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Microbial mat A microbial mat is a multi-layered sheet of microorganisms, mainly bacteria and archaea. Microbial mats grow at interfaces between different types of material, mostly on submerged or moist surfaces, but a few survive in deserts. They colonize environments ranging in temperature from –40 °C to 120 °C. A few are found as endosymbionts of animals. Although only a few centimetres thick at most, microbial mats create a wide range of internal chemical environments, and hence generally consist of layers of microorganisms that can feed on or at least tolerate the dominant chemicals at their level and which are usually of closely related species. In moist conditions mats are usually held together by slimy substances secreted by the microorganisms, and in many cases some of the microorganisms form tangled webs of filaments which make the mat tougher. The best known physical forms are flat mats and stubby pillars called stromatolites, but there are also spherical forms. Microbial mats are the earliest form of life on Earth for which there is good fossil evidence, from , and have been the most important members and maintainers of the planet's ecosystems. Originally they depended on hydrothermal vents for energy and chemical "food", but the development of photosynthesis allow mats to proliferate outside of these environments by utilizing a more widely available energy source, sunlight | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,863 |
Microbial mat The final and most significant stage of this liberation was the development of oxygen-producing photosynthesis, since the main chemical inputs for this are carbon dioxide and water. As a result, microbial mats began to produce the atmosphere we know today, in which free oxygen is a vital component. At around the same time they may also have been the birthplace of the more complex eukaryote type of cell, of which all multicellular organisms are composed. Microbial mats were abundant on the shallow seabed until the Cambrian substrate revolution, when animals living in shallow seas increased their burrowing capabilities and thus broke up the surfaces of mats and let oxygenated water into the deeper layers, poisoning the oxygen-intolerant microorganisms that lived there. Although this revolution drove mats off soft floors of shallow seas, they still flourish in many environments where burrowing is limited or impossible, including rocky seabeds and shores, hyper-saline and brackish lagoons, and are found on the floors of the deep oceans. Because of microbial mats' ability to use almost anything as "food", there is considerable interest in industrial uses of mats, especially for water treatment and for cleaning up pollution. Microbial mats have also been referred to as "algal mats" and "bacterial mats" in older scientific literature. They are a type of biofilm that is large enough to see with the naked eye and robust enough to survive moderate physical stresses | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,864 |
Microbial mat These colonies of bacteria form on surfaces at many types of interface, for example between water and the sediment or rock at the bottom, between air and rock or sediment, between soil and bed-rock, etc. Such interfaces form vertical chemical gradients, i.e. vertical variations in chemical composition, which make different levels suitable for different types of bacteria and thus divide microbial mats into layers, which may be sharply defined or may merge more gradually into each other. A variety of microbes are able to transcend the limits of diffusion by using "nanowires" to shuttle electrons from their metabolic reactions up to two centimetres deep in the sediment – for example, electrons can be transferred from reactions involving hydrogen sulfide deeper within the sediment to oxygen in the water, which acts as an electron acceptor. The best-known types of microbial mat may be flat laminated mats, which form on approximately horizontal surfaces, and stromatolites, stubby pillars built as the microbes slowly move upwards to avoid being smothered by sediment deposited on them by water. However, there are also spherical mats, some on the outside of pellets of rock or other firm material and others "inside" spheres of sediment. A microbial mat consists of several layers, each of which is dominated by specific types of microorganism, mainly bacteria | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,865 |
Microbial mat Although the composition of individual mats varies depending on the environment, as a general rule the by-products of each group of microorganisms serve as "food" for other groups. In effect each mat forms its own food chain, with one or a few groups at the top of the food chain as their by-products are not consumed by other groups. Different types of microorganism dominate different layers based on their comparative advantage for living in that layer. In other words, they live in positions where they can out-perform other groups rather than where they would absolutely be most comfortable — ecological relationships between different groups are a combination of competition and co-operation. Since the metabolic capabilities of bacteria (what they can "eat" and what conditions they can tolerate) generally depend on their phylogeny (i.e. the most closely related groups have the most similar metabolisms), the different layers of a mat are divided both by their different metabolic contributions to the community and by their phylogenetic relationships. In a wet environment where sunlight is the main source of energy, the uppermost layers are generally dominated by aerobic photosynthesizing cyanobacteria (blue-green bacteria whose color is caused by their having chlorophyll), while the lowest layers are generally dominated by anaerobic sulfate-reducing bacteria. Sometimes there are intermediate (oxygenated only in the daytime) layers inhabited by facultative anaerobic bacteria | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,866 |
Microbial mat For example, in hypersaline ponds near Guerrero Negro (Mexico) various kind of mats were explored. There are some mats with a middle purple layer inhabited by photosynthesizing purple bacteria. Some other mats have a white layer inhabited by chemotrophic sulfide-oxidizing bacteria and beneath them an olive layer inhabited by photosynthesizing green sulfur bacteria and heterotrophic bacteria. However, this layer structure is not changeless during a day: some species of cyanobacteria migrate to deeper layers at morning, and go back at evening, to avoid intensive solar light and UV radiation at mid-day. Microbial mats are generally held together and bound to their substrates by slimy extracellular polymeric substances which they secrete. In many cases some of the bacteria form filaments (threads), which tangle and thus increase the colonies' structural strength, especially if the filaments have sheaths (tough outer coverings). This combination of slime and tangled threads attracts other microorganisms which become part of the mat community, for example protozoa, some of which feed on the mat-forming bacteria, and diatoms, which often seal the surfaces of submerged microbial mats with thin, parchment-like coverings. Marine mats may grow to a few centimeters in thickness, of which only the top few millimeters are oxygenated. Underwater microbial mats have been described as layers that live by exploiting and to some extent modifying local chemical gradients, i.e. variations in the chemical composition | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,867 |
Microbial mat Thinner, less complex biofilms live in many sub-aerial environments, for example on rocks, on mineral particles such as sand, and within soil. They have to survive for long periods without liquid water, often in a dormant state. Microbial mats that live in tidal zones, such as those found in the Sippewissett salt marsh, often contain a large proportion of similar microorganisms that can survive for several hours without water. Microbial mats and less complex types of biofilm are found at temperature ranges from –40 °C to +120 °C, because variations in pressure affect the temperatures at which water remains liquid. They even appear as endosymbionts in some animals, for example in the hindguts of some echinoids. Microbial mats use all of the types of metabolism and feeding strategy that have evolved on Earth—anoxygenic and oxygenic photosynthesis; anaerobic and aerobic chemotrophy (using chemicals rather than sunshine as a source of energy); organic and inorganic respiration and fermentation (i..e converting food into energy with and without using oxygen in the process); autotrophy (producing food from inorganic compounds) and heterotrophy (producing food only from organic compounds, by some combination of predation and detritivory). Most sedimentary rocks and ore deposits have grown by a reef-like build-up rather than by "falling" out of the water, and this build-up has been at least influenced and perhaps sometimes caused by the actions of microbes | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,868 |
Microbial mat Stromatolites, bioherms (domes or columns similar internally to stromatolites) and biostromes (distinct sheets of sediment) are among such microbe-influenced build-ups. Other types of microbial mat have created wrinkled "elephant skin" textures in marine sediments, although it was many years before these textures were recognized as trace fossils of mats. Microbial mats have increased the concentration of metal in many ore deposits, and without this it would not be feasible to mine them—examples include iron (both sulfide and oxide ores), uranium, copper, silver and gold deposits. Microbial mats are among the oldest clear signs of life, as microbially induced sedimentary structures (MISS) formed have been found in western Australia. At that early stage the mats' structure may already have been similar to that of modern mats that do not include photosynthesizing bacteria. It is even possible that non-photosynthesizing mats were present as early as . If so, their energy source would have been hydrothermal vents (high-pressure hot springs around submerged volcanoes), and the evolutionary split between bacteria and archea may also have occurred around this time. The earliest mats were probably small, single-species biofilms of chemotrophs that relied on hydrothermal vents to supply both energy and chemical "food" | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,869 |
Microbial mat Within a short time (by geological standards) the build-up of dead microorganisms would have created an ecological niche for scavenging heterotrophs, possibly methane-emitting and sulfate-reducing organisms that would have formed new layers in the mats and enriched their supply of biologically useful chemicals. It is generally thought that photosynthesis, the biological generation of energy from light, evolved shortly after (3 billion). However an isotope analysis suggests that oxygenic photosynthesis may have been widespread as early as . The eminent researcher into Earth's earliest life, William Schopf, argues that, if one did not know their age, one would classify some of the fossil organisms in Australian stromatolites from as cyanobacteria, which are oxygen-producing photosynthesizers. There are several different types of photosynthetic reaction, and analysis of bacterial DNA indicates that photosynthesis first arose in anoxygenic purple bacteria, while the oxygenic photosynthesis seen in cyanobacteria and much later in plants was the last to evolve. The earliest photosynthesis may have been powered by infra-red light, using modified versions of pigments whose original function was to detect infra-red heat emissions from hydrothermal vents. The development of photosynthetic energy generation enabled the microorganisms first to colonize wider areas around vents and then to use sunlight as an energy source | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,870 |
Microbial mat The role of the hydrothermal vents was now limited to supplying reduced metals into the oceans as a whole rather than being the main supporters of life in specific locations. Heterotrophic scavengers would have accompanied the photosynthesizers in their migration out of the "hydrothermal ghetto". The evolution of purple bacteria, which do not produce or use oxygen but can tolerate it, enabled mats to colonize areas that locally had relatively high concentrations of oxygen, which is toxic to organisms that are not adapted to it. Microbial mats would have been separated into oxidized and reduced layers, and this specialization would have increased their productivity. It may be possible to confirm this model by analyzing the isotope ratios of both carbon and sulfur in sediments laid down in shallow water. The last major stage in the evolution of microbial mats was the appearance of cyanobacteria, photosynthesizers which both produce and use oxygen. This gave undersea mats their typical modern structure: an oxygen-rich top layer of cyanobacteria; a layer of photosynthesizing purple bacteria that could tolerate oxygen; and oxygen-free, HS-dominated lower layers of heterotrophic scavengers, mainly methane-emitting and sulfate-reducing organisms. It is estimated that the appearance of oxygenic photosynthesis increased biological productivity by a factor of between 100 and 1,000 | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,871 |
Microbial mat All photosynthetic reactions require a reducing agent, but the significance of oxygenic photosynthesis is that it uses water as a reducing agent, and water is much more plentiful than the geologically produced reducing agents on which photosynthesis previously depended. The resulting increases in the populations of photosynthesizing bacteria in the top layers of microbial mats would have caused corresponding population increases among the chemotrophic and heterotrophic microorganisms that inhabited the lower layers and which fed respectively on the by-products of the photosynthesizers and on the corpses and / or living bodies of the other mat organisms. These increases would have made microbial mats the planet's dominant ecosystems. From this point onwards life itself produced significantly more of the resources it needed than did geochemical processes. Oxygenic photosynthesis in microbial mats would also have increased the free oxygen content of the Earth's atmosphere, both directly by emitting oxygen and because the mats emitted molecular hydrogen (H), some of which would have escaped from the Earth's atmosphere before it could re-combine with free oxygen to form more water. Microbial mats thus played a major role in the evolution of organisms which could first tolerate free oxygen and then use it as an energy source | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,872 |
Microbial mat Oxygen is toxic to organisms that are not adapted to it, but greatly increases the metabolic efficiency of oxygen-adapted organisms — for example anaerobic fermentation produces a net yield of two molecules of adenosine triphosphate, cells' internal "fuel", per molecule of glucose, while aerobic respiration produces a net yield of 36. The oxygenation of the atmosphere was a prerequisite for the evolution of the more complex eukaryote type of cell, from which all multicellular organisms are built. Cyanobacteria have the most complete biochemical "toolkits" of all the mat-forming organisms: the photosynthesis mechanisms of both green bacteria and purple bacteria; oxygen production; and the Calvin cycle, which converts carbon dioxide and water into carbohydrates and sugars. It is likely that they acquired many of these sub-systems from existing mat organisms, by some combination of horizontal gene transfer and endosymbiosis followed by fusion. Whatever the causes, cyanobacteria are the most self-sufficient of the mat organisms and were well-adapted to strike out on their own both as floating mats and as the first of the phytoplankton, which forms the basis of most marine food chains. The time at which eukaryotes first appeared is still uncertain: there is reasonable evidence that fossils dated between and represent eukaryotes, but the presence of steranes in Australian shales may indicate that eukaryotes were present | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,873 |
Microbial mat There is still debate about the origins of eukaryotes, and many of the theories focus on the idea that a bacterium first became an endosymbiont of an anaerobic archean and then fused with it to become one organism. If such endosymbiosis was an important factor, microbial mats would have encouraged it. There are two possible variations of this scenario: Microbial mats from ~ provide the first evidence of life in the terrestrial realm. The Ediacara biota are the earliest widely accepted evidence of multicellular "animals". Most Ediacaran strata with the "elephant skin" texture characteristic of microbial mats contain fossils, and Ediacaran fossils are hardly ever found in beds that do not contain these microbial mats. Adolf Seilacher categorized the "animals" as: "mat encrusters", which were permanently attached to the mat; "mat scratchers", which grazed the surface of the mat without destroying it; "mat stickers", suspension feeders that were partially embedded in the mat; and "undermat miners", which burrowed underneath the mat and fed on decomposing mat material. In the Early Cambrian, however, organisms began to burrow vertically for protection or food, breaking down the microbial mats, and thus allowing water and oxygen to penetrate a considerable distance below the surface and kill the oxygen-intolerant microorganisms in the lower layers | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,874 |
Microbial mat As a result of this Cambrian substrate revolution, marine microbial mats are confined to environments in which burrowing is non-existent or negligible: very harsh environments, such as hyper-saline lagoons or brackish estuaries, which are uninhabitable for the burrowing organisms that broke up the mats; rocky "floors" which the burrowers cannot penetrate; the depths of the oceans, where burrowing activity today is at a similar level to that in the shallow coastal seas before the revolution. Although the Cambrian substrate revolution opened up new niches for animals, it was not catastrophic for microbial mats, but it did greatly reduce their extent. Most fossils preserve only the hard parts of organisms, e.g. shells. The rare cases where soft-bodied fossils are preserved (the remains of soft-bodied organisms and also of the soft parts of organisms for which only hard parts such as shells are usually found) are extremely valuable because they provide information about organisms that are hardly ever fossilized and much more information than is usually available about those for which only the hard parts are usually preserved. Microbial mats help to preserve soft-bodied fossils by: The ability of microbial mat communities to use a vast range of "foods" has recently led to interest in industrial uses. There have been trials of microbial mats for purifying water, both for human use and in fish farming, and studies of their potential for cleaning up oil spills | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,875 |
Microbial mat As a result of the growing commercial potential, there have been applications for and grants of patents relating to the growing, installation and use of microbial mats, mainly for cleaning up pollutants and waste products. | Biology | https://en.wikipedia.org/wiki?curid=18229656 | Microbial mat | 139,876 |
DuPont Danisco Cellulosic Ethanol LLC is a 50/50 joint venture between DuPont and Genencor, a subsidiary of Danisco. The company is accelerating development and deployment of cellulosic ethanol, which is made from non-food biomass. DDCE plans to license its technology and also will engage in limited operations of cellulosic ethanol biorefineries. The company's collaborations include work with Genera Energy and the University of Tennessee Research Foundation DDCE has constructed a demonstration-scale biorefinery and research and development facility for cellulosic ethanol in Vonore, Tennessee. The plant went into operation at the end of 2009. DDCE was founded in 2008, but was eventually dissolved in 2011 due to the acquisition of Danisco by DuPont. | Biology | https://en.wikipedia.org/wiki?curid=18229900 | DuPont Danisco | 139,877 |
Glossary of botanical terms This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology. For other related terms, see Glossary of phytopathology and List of Latin and Greek words commonly used in systematic names. | Biology | https://en.wikipedia.org/wiki?curid=18238240 | Glossary of botanical terms | 139,878 |
Tussock grasslands of New Zealand Tussock grasslands form expansive and distinctive landscapes in the South Island and to a lesser extent in the central plateau region of the North Island of New Zealand. Most of the plants referred to as tussocks are in the genera "Carex", "Chionochloa", "Festuca", and "Poa". What would be termed "herbfields" for European mountains, and bunchgrass meadows in North America, are referred to as tussock herbfields in New Zealand due to a dominance of this type of plant. Species of the genus "Chionochloa" dominate in these areas. The larger tussocks are called snow grass (or less commonly as snow tussocks) and may grow up to 2 metres in height. They grow slowly and some specimens are estimated to be several centuries old. | Biology | https://en.wikipedia.org/wiki?curid=18240273 | Tussock grasslands of New Zealand | 139,879 |
Dawkins vs. Gould Dawkins vs. Gould: Survival of the Fittest is a book about the differing views of biologists Richard Dawkins and Stephen Jay Gould by philosopher of biology Kim Sterelny. When first published in 2001 it became an international best-seller. A new edition was published in 2007 to include Gould's "The Structure of Evolutionary Theory" finished shortly before his death in 2002, and more recent works by Dawkins. The synopsis below is from the 2007 publication. In the introductory chapter the author points out that there have been many conflicts in biology. Still, few have been as public or as polemical as the one between Dawkins and Gould. Dawkins sees evolution as a competition between gene lineages, where organisms are vehicles for those genes. Gould, a palaeontologist in the tradition of George Gaylord Simpson, has a different perspective. For example, he sees chance as very important, and views organisms as being more important than genes. Their broader world views also differ, for instance they have very different beliefs about the relationship between religion and science. This begins with a discussion on genes and gene lineages (chapter 2). Dawkins' view on the nature of evolution, as outlined in "The Selfish Gene", has genes as the units of selection, both in the first replicators and in more complex organisms, where alliances of genes are formed (and sometimes broken) | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,880 |
Dawkins vs. Gould He then discusses in chapter 3, Dawkins' view of heritability, with genes as difference makers that satisfy replicator principles and have phenotypic power, increasing the likelihood of phenotypic expression, depending on environmental context. In chapter 4, he discusses aspects of genomes and genetic replication, using various examples. He notes that in a story about magpie aggression, "Dawkins' story will be about genes and vehicles", whereas Gould and others will describe it in terms of phenotypic fitness. (p. 39) He discusses ways in which genes "lever their way into the next generation", including genes that are loners, or 'Outlaws', and which promote their own replication at the expense of other genes in their organism's genome. He then discusses the role of extended phenotypes, in which genotypes that influence their environment further increase the likelihood of replication (chapter 4). Chapter 5 explores selfish genes and the selection within the animal kingdom of co-operation as opposed to altruism, levels of selection, and the evolution of evolvability itself. Sterelny notes that on the issue of high-level selection, "Dawkins and Gould are less sharp than they once were." (p. 65) In chapter 6, Sterelny notes that "despite the heat of some recent rhetoric, the same is true of the role of selection in generating evolutionary change", (p. 67) and naive adaptationism | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,881 |
Dawkins vs. Gould "Everyone accepts that many characteristics of organisms are not the direct result of selection", as in the example of redness of blood, which is a by-product of its oxygen-carrying properties. (p. 70) Numerous general truths are uncontroversial "though their application to particular cases may be. Nor is there disagreement between Gould and Dawkins on core cases", such as echolocation in bats, which "everyone agrees is an adaptation". (p. 71) They do however differ on the relative role of selection and variation. For example, they have different emphases on development. Developmental constraints are fundamental to Gould's approach. Dawkins gives this less weight, and has been more interested in enhanced possibilities open to lineages as a result of developmental revolutions. For example, the evolution of segmentation increases variation possibilities. He discusses this in "Climbing Mount Improbable", and "returns to similar themes at the end of "The Ancestor's Tale": major transitions in evolution are developmental transitions, transitions that make new variants possible, and hence new adaptive complexes possible". (pp. 77–78) "Gould, on the other hand, is inclined to bet that the array of possibilities open to a lineage is tightly restricted, often to minor variants of its current state." (p. 78) Gould sees morphological stability as "probably explained by constraints on the supply of variation to selection". (p | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,882 |
Dawkins vs. Gould 78) But whereas in his earlier work Gould considered variation supply as a brake on evolutionary change, in "The Structure of Evolutionary Theory" he carefully notes that it can also enhance possibilities for change. "So while both Dawkins and Gould recognise the central role of developmental biology in an explanation of evolutionary change, they make different bets as to what the role will be. Gould but not Dawkins thinks that one of these roles is as a brake", damping down change possibilities. (p. 78) Another difference is Dawkins conception of evolutionary biology's central problem as the explanation of adaptive complexity, whereas Gould has largely focused on the existence of large-scale patterns in the history of life that are not explained by natural selection. "A further disagreement concerns the existence and importance of these patterns", (p. 79) which leads on to Part III. In discussing Gould's perspective, Sterelny begins with two fundamental distinctions that Gould saw between his viewpoint and that of the Dawkins camp. Firstly, Gould thought that gene selectionists misrepresent the role of genes in microevolution, ascribing a causal role in evolution, rather than by-product record of evolutionary change. Moreover, evolutionary biologists have often neglected non-selective possibilities when formulating hypotheses about microevolutionary change | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,883 |
Dawkins vs. Gould For example, contemporary sex differences in human males and females need not be adaptations, but could be evolutionary vestiges of a greater sexual dimorphism in ancestral species. But Gould's main target is 'extrapolationism', concerning the relationship between evolutionary processes occurring within species and those of large-scale life histories. In this view, the evolution of species lineages is an aggregate of events at the local population scale, with major changes being the additive result of minor changes over successive generations. While not disputing the relevance of this, Gould argued that it is not the whole truth. "Indeed, it is not much of an exaggeration to say that Gould's professional life has been one long campaign against the idea that this history of life is nothing but the long, long accumulation of local events." (p. 86) Sterelny offers four highlights to illustrate this. Firstly, punctuated equilibrium, in which new species arise by a split in a parental species, followed by geologically rapid speciation of one or both of the fragments. A period of stasis then occurs until the species either becomes extinct or splits again. Gould argued that punctuated equilibrium challenges the gradual change expected by extrapolationists. In the case of Hominid evolution, there is the evolutionary trend of marked increase in brain size. To Gould, this trend was the result of species sorting, in which species with relatively larger brains were more likely to appear, or to survive | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,884 |
Dawkins vs. Gould Secondly, in his Natural History writings, Gould often argued that the history of life was profoundly affected by mass extinctions caused by environmental catastrophes such as an asteroid impact causing the Cretaceous–Paleogene extinction event, which wiped out pterosaurs, large marine reptiles and non-avian dinosaurs 66 million years ago. Such a mass extinction would be sudden at not just the larger geological time-scale, but also the more ephemeral ecological one. "The properties that are visible to selection and evolution in local populations—the extent to which an organism is suited to life here and now" become irrelevant to survival prospects in mass extinction times. "Survival or extinction in mass extinction episodes determines the large-scale shape of the tree of life". Massive culling of synapsids at the end of the Permian "gave the dinosaurs their chance. The death of the dinosaurs opened the door for the radiation of mammals." (p. 89) Thirdly, in "Wonderful Life", Gould describes the Burgess Shale fauna, which is known in detail due to fortuitous preservation of both hard and soft tissue around 505 million years ago. Gould argues that the Burgess Shale fauna demonstrate both diversity of species and disparity of body plans. He accepts that diversity has probably increased over the last few million years, but argues that disparity of animal life peaked early in evolutionary history, with very little disparity generated since the Cambrian, and profound conservatism in surviving lineages | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,885 |
Dawkins vs. Gould For example, despite diversity in beetle species their body plans follow the same general pattern. He argues that survival has been contingent, and that if the tape of life was replayed from the earliest Cambrian, with small alterations in the initial conditions, a different set of survivors may have evolved. Fourth, in "", "Gould argues that evolutionary trends are not the scaled-up consequences of competitive interactions among organisms." (p. 90) For example, morphological changes in horses are not the cumulative result of the competitive success of horses better adapted to grazing. "Rather, Gould argues that this trend is really a change in the spread of variation within the horse lineage", which used to be species rich with a wide range of lifestyles and sizes. "But only a very few species survived, and those few happen to be largish horses. The average horse is larger now only because almost all horse species became extinct, and the few survivors happened to be somewhat atypical", and there is no evolutionary 'trend' towards increased size. (p. 91) Similarly with complexity. While complexity has increased over time, it is misleading to see this simply as a trend towards increased complexity, from simple organisms such as bacteria to complex organisms such as us. Rather, the distance from the least to the most complex living organism has increased. "The real phenomenon to be explained is this increase in variation rather than an upward trend in average complexity. There is, Gould argues, no such trend | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,886 |
Dawkins vs. Gould " (p. 92) Sterelny notes two issues arising from consideration of Gould's case against extrapolationism. "Are the patterns in life's history that he claims to detect real? And do these patterns really show the existence of evolutionary mechanisms other than those operating at the scale of local populations?" (p. 92) Sterelny then outlines in chapter 8 Gould and Eldredge's punctuated equilibrium hypothesis. They argued that the appearance of stability in species evolution is not a mere effect of the gappiness and imperfection of the fossil record. Rather, it is the result of discontinuous tempos of change in the process of speciation and the deployment of species in geological time. Sterelny notes that this hypothesis has been misunderstood in two important ways. First, in some early discussions of the idea, the contrast between geological and ecological time was blurred, with Gould and Eldredge interpreted as claiming that species originate more or less overnight in a single step. However, Gould and Eldredge were referring to geological time, in which speciation taking 50,000 years would seem instantaneous relative to a species existence over millions of years. A second misunderstanding relates to further evolutionary change following speciation. They are not claiming that there is no generational change at all. "Lineages do change. But the change between generations does not accumulate. Instead, over time, the species wobbles about its phenotypic mean | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,887 |
Dawkins vs. Gould Jonathan Weiner's The Beak of the Finch describes this very process." (p. 96) Sterelny notes that despite the fact that the fossil record represents, for several reasons, a biased sample, "the consensus seems to be shifting Gould's way: the punctuated equilibrium pattern is common, perhaps even predominant". Yet even if stasis is common "why suppose that this is bad news for the extrapolationist orthodoxy?" (p. 97) He notes that "the problem is not stasis but speciation. How can events in a local population generate a new species?" (p. 98) In discussing this issue, he notes "any solution to the speciation problem will take us beyond events in local populations observable on human timescales", and "it is likely that whatever explains the occasional transformation of a population into a species will rely on large-scale but rare climatic, biological, geographic or geological events; events which isolate populations until local change is entrenched". (p. 99) He notes that speciation is not just the accumulation of events in a local population, but dependent on the population's embeddedness into a larger whole. "There is a break with a strong version of extrapolationism, but it is not a radical break. Dawkins could, should, and probably would accept it; in "The Ancestor's Tale", he has an inclusive view of speciation mechanisms." (p | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,888 |
Dawkins vs. Gould 100) Thus, while "Gould somewhat overstates the adherence of orthodoxy to strict extrapolationism", punctuated equilibrium is more important than some of the more "ungenerous treatment" that has been meted out. (pp. 100–101) In chapter 9, Sterelny discusses mass extinction, and notes Gould's hypothesis that mass extinctions are more frequent, rapid, intense and different in their effects than has been supposed. (p. 108) Moreover, Gould argues that during such extinctions, there are evolutionary principles that would enable the prediction of winners and losers. "The game has rules. But they are different rules from those of normal times ... Species survival is not random, but the properties on which survival depends are not adaptations to the danger mass extinction threatens. If a meteor impact caused a nuclear winter, then the ability to lie dormant would have improved your chances. But dormancy is not an adaptation to the danger of meteor impacts." (p. 110) Similarly, "species with broad geographical ranges, species with broad habitat tolerances, species whose lifecycle does not tie them too closely to a particular type of community all would have had a better chance of making it", (p. 110) and this amounts to species selection. However, as Gould concedes, there are no well-worked-out case studies | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,889 |
Dawkins vs. Gould "In short, Gould's case for the importance of mass extinction depends on the view that there is a qualitative difference between mass extinction and background extinction, and that major groups have disappeared that would otherwise have survived". (p. 113) A plausible but difficult to prove claim, as is the claim that mass extinction regimes are species selection regimes. In chapter 10, Sterelny discusses the fossil evidence of Cambrian fauna, and how this provides the basis for Gould's challenge to gradualistic orthodoxy. About 543 million years ago, at the base of the Cambrian, the Ediacaran fauna, characterised by small shelly fossils, fossilised tracks, and burrows, apparently disappeared. From available evidence, diversity of fauna was very limited at the beginning of the Cambrian Period. "By the middle of the Cambrian, about 520 million years ago, animal life was rich and diverse", (p. 116) as demonstrated by the Maotianshan Shales fossils, in Chengjiang, China, which "are as spectacular as the Burgess Shale fauna, and significantly older." (p. 116) "Thus the fossil record seems to show that most of the major animal groups appeared simultaneously. In the 'Cambrian explosion', we find segmented worms, velvet worms, starfish and their allies, molluscs (bivalves, snails, squid and their relatives), sponges, brachiopods and other shelled animals appearing all at once, with their basic organisation, organ systems and sensory mechanisms already operational." (p | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,890 |
Dawkins vs. Gould 116) "This explosive evolutionary radiation of the Cambrian seems to be unique. Plants seem to have arisen somewhat more gradually ... nor was there a similar radiation when animals invaded the land ... the colonisation of the land saw no new ways of making an animal." (p. 117) Despite adaptations, the basic body plans remain recognisable. One possibility is that the 'Cambrian explosion' is "an illusion generated by the failure of earlier Precambrian fossils to survive to our times," (p. 117) that there is a long history of hidden evolution preceding the appearance of multi-celled animals in the fossil record. "This remains a live option. There are fossil embryos of animals from China dating to about 570 million years ago", (p. 120) and there are many animal lineages for which there is no fossil record, possibly due to being small and soft-bodied, so leaving no detectable traces. Certainly Precambrian animal life is evidenced by the Ediacaran fossils, but the relationship between fauna from these two periods remains unclear. Gould was inclined to support the view that the Ediacaran fauna became wholly extinct prior to the Cambrian, thus were not Cambrian ancestors, "hence their existence does not extend the timeframe of animal evolution into the Precambrian". (p. 120) However, the development of methods of calibrating rates of change in DNA sequences has given the ability to estimate the last common ancestor of various lineages | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,891 |
Dawkins vs. Gould It also allows the obtaining of molecular clock dates for lineages without a fossil record, which shows that zero-fossil phyla are also ancient. Such information comes with important caveats in relation to methodology, including the underlying assumptions of each method. "However, even the youngest dates from molecular clocks place the origins of the deepest branches in the tree of animal life—where the sponges and jellyfish branch off from the other early animals—over 600 million years ago, and so quite deep in the Precambrian." (p. 125) Gould accepted this, but noted that this does not negate the Cambrian Explosion. Molecular clocks date origins, while fossils date geographical spread and morphology. Molecular clock data cannot decide between gradual morphological change and rapid evolutionary bursts after initial species divergence. "Moreover, Gould argues that the fossil record supports the model in which the lineage splits much earlier than the distinctive morphologies evolve. For that explains why we find no Precambrian proto-arthropod fossils. In short, the 'hidden history' hypothesis remains an open option, but so does Gould's guess that the Cambrian explosion was genuinely explosive rather than an illusion generated by incomplete preservation." (pp. 125–126) Of relevance to the explosive radiation hypothesis are the findings from the Cambrian sites: the Burgess (~505 myr), the Chengjiang (~522 myr), and the Sirius Passet formation in Greenland, which is dated at about 518 million years Before Present | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,892 |
Dawkins vs. Gould Sterelny describes the distinction between disparity and diversity, and then explores Gould's claim that since the Cambrian, diversity has increased, but disparity has decreased. Since the Cambrian, not just species within phyla, but whole phyla themselves have become extinct. The major subdivisions of animal life are phyla, each of which is a distinctive way of building an animal. Gould's claim is that "the Cambrian phylum count was larger, maybe much larger, than the contemporary count. No new phyla have appeared, and many have gone. That count, in turn, is a reasonable measure of disparity. So Cambrian disparity was considerably larger than current disparity. The history of animal life is not a history of gradually increasing differentiation. It is a history of exuberant initial proliferation followed by much loss; perhaps sudden loss." (p. 129) Gould doubted that selection played much role in either the early burst of disparity, the post-Cambrian conservativeness of evolution, or the roster of loss and survival. To Gould, there is a conservative pattern of history indicated by a reduction in disparity as measured by both the lack of new body plans and the lack of any major modifications of old ones. Given that evolution in general has not ceased in the past 500 million years, this poses a number of questions. However, Dawkins and more so his former student Mark Ridley think Gould's basic claim about history's pattern is incorrect | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,893 |
Dawkins vs. Gould Central to Ridley's approach is cladistics, in which the purpose of biological systematics is to discover and represent genealogical relationships between species. Biological classifications are thus evolutionary genealogies, where only monophyletic groups (e.g. genera, families, orders, classes, phyla) are recognised and named. To cladists, similarity and dissimilarity are not objective features of the living world; they are products of human perceptions. Thus, whereas some morphological and physiological differences are more salient to us, and more striking or surprising, this is a fact about us, not the history of life. Conversely, genealogical reconstructions—who is related to whom—are objective facts independent of the observer's perception. Sterelny discusses how both cladists and Dawkins think that Gould overestimates Cambrian disparity, and he notes that while the distinction between disparity and diversity is very plausible, in the absence of a good account of the nature of disparity, and objective measures, "the existence of Gould's puzzling pattern remains conjectural". (p. 141) Finally, in chapter 11, Sterelny discusses the "evolutionary escalator", or the tendency over time for life on earth to show a progressive increase both in complexity and adaptivity. While Gould does not outright reject this, he thinks it is a misleading way to think about the history of life | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,894 |
Dawkins vs. Gould As above, with the example of horses, Gould argues that there has been no directional trend, but rather, a massive extinction in the horse lineage, with the surviving remnants happening to be largish grazers. So the appearance of a trend is generated by a reduction in heterogeneity. "A trend which is hostage to one switch between life and death is no trend at all." (p. 146) At the scale of complexity, the same applies. "What we think of as a progressive increase in complexity is a change in the difference between the least and the most complex organism. It is a change in the spread of complexity." (p. 146) Life starts in the simplest form that the constraints of chemistry and physics will allow, with bacteria probably close to that limit. "So life starts at the minimum level of complexity. Since even now nearly everything that is alive is a bacterium, for the most part life has stayed that way." (p. 146) But occasionally life builds a lineage that becomes more complex over time. There are no global evolutionary mechanisms that either prevent more complex organisms evolving from simpler ones, or that make it more likely to occur. Complexity tends to drift up because the point of life's origin is close to the physical lower bound. Such complex creatures are relatively less than bacteria, which still dominate life, but the difference between the simplest and most complex organisms tends to become greater over time. So the increased range is wholly undirected | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,895 |
Dawkins vs. Gould Displayed as a frequency distribution curve or histogram, the shape would be skewed to the right (i.e. positively skewed), with the mode near the left. Over time, the range would increase as average complexity drifts upwards. But the mode would remain at left, with the curve spreading to the right, because there is a wall imposed by the laws of the physical sciences to the left, but not to the right. To Gould, this upward drift in complexity is not the same as directional progress. 'Replaying the tape' of life's history would not guarantee the same outcomes, especially as mass extinction events make history utterly unpredictable. Conversely, Dawkins and Simon Conway Morris think that the course of evolutionary history is more predictable than does Gould. They argue that "convergent evolution is such a ubiquitous feature of evolution that the broad outline of evolution is highly predictable. Evolutionary pathways are constrained by both opportunity and possibility. There are not many ways of building working organisms, and so we can predict that evolution will move along this small set of pathways. Many of the most distinctive features of living systems have evolved more than once. Some of them (like eyes) have evolved many times." (p. 149) Also, Dawkins thinks that evolution is progressive, not in an anthropocentric sense, but because over time life is becoming better adapted, although not in every aspect, as when local conditions change and organisms must move or readapt | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,896 |
Dawkins vs. Gould "There is no reason to suppose that there is any arrow of overall improvement here." (p. 150) However, Dawkins thinks that relationships between organisms and their enemies, such as predator-prey, or parasite-host relationships, are locked into a permanent arms race, and such lineages generate progressive change. "Both predator and prey will become absolutely more efficient in hunting and avoiding hunters, though their relative success with respect to one another may not change at all over time." (p. 151) Thus progress is real though partial and intermittent. "Partial because it is generated only when selective regimes are both directional and stable: selecting for the same kind of phenotypic change over long periods, as in arms races ... intermittent because every arms race will ultimately be disrupted by large-scale environmental changes." (p. 151) However, while they were in progress, each lineage was objectively improving. To Sterelny, Gould overstates his case, and "there is more to the history of life's complexity than a gradual increase in variance". (p. 151) He cites the 1995 work "The Major Transitions in Evolution" by John Maynard Smith and Eörs Szathmáry, in which life's history involves a series of major transitions and hence inherent directionality, with each transition facilitating possibilities for the evolution of more complex organisms | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,897 |
Dawkins vs. Gould Dawkins pursues a similar, though less detailed, argument* in discussing the evolution of evolvability, in which a series of 'watershed events' make new life forms possible. These watersheds in evolvability comprise the evolution of sex, of multi-celled life together with a life cycle that takes large organisms through a single-celled reproduction stage, and the evolution of a modular mode of the development and construction of bodies. "Segmentation, for Dawkins, is a special case of modularity; of building a creature out of relatively discrete chunks. For once a chunk has been invented by evolution, it can be modified or redeployed without stuffing up the rest of the organism." (p. 152) While Gould too is interested in evolvability, the crucial difference between Gould's view, and that of Maynard Smith, Szathmary and Dawkins, is in how they see the spread of complexity. To Gould, complexity drifts upward, having a lower boundary or wall to the left, "but no upper bound, and these features of complexity are fixed by biochemistry, not the course of evolutionary history". (p. 153) Maynard Smith and Szathmary consider that evolutionary history has had upper bounds, or walls to the right. For example, until eukaryotic life evolved, there was an upper bound of complexity set by the intrinsic limits on the size and structural complexity of prokaryotes, and for "perhaps 2 billion years, bacterial evolution was confined between these two limits." (p | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,898 |
Dawkins vs. Gould 153) Similarly, until a series of evolutionary innovations facilitated the evolution of multi-celled organisms, eukaryotic complexity was set by the limits on a single eukaryotic cell. "Maynard Smith and Szathmary argue that social existence, too, has evolutionary preconditions. Until these are met, a wall remains to the right." (p. 153) Whereas to Gould, there are unchanging boundaries set by physics and chemistry, Maynard Smith, Szathmary and Dawkins view evolution as irreversibly transforming these boundaries. "The eukaryotic cell, sexual reproduction and cellular differentiation all change the nature of evolutionary possibility. These possibilities have changed over time in a direction that increases the maximum attainable complexity. In short, over time the rules of evolution change." (pp. 153–154) So evolvability has changed, with developmental mechanisms determining the variation available to selection. Gould claims that bacteria dominate every age, including this one.* They are the world's most numerous organisms, have the most disparate metabolic pathways, and may constitute most of the world's biomass. "All this is true and important", with Dawkins making similar observations.* "But it is not the whole truth. We live in an age in which many biological structures are now possible that were once not possible. That too is true, and important." (p | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,899 |
Dawkins vs. Gould 153) In Chapter 12, Sterelny notes that "Dawkins and his allies really do have a different conception of evolution from that embraced by Eldredge, Lewontin and other collaborators of Gould", but that this does not explain the undercurrent of hostility generated in the debate, as illustrated by a series of exchanges in the "New York Review of Books". But the issues pertain mostly to matters internal to evolutionary theory, and apart from banal psychological explanations pertaining to human reaction to public criticism, Sterelny thinks that at core is their different attitudes to science itself. To Dawkins, science is not just a light in the dark, but "by far our best, and perhaps our only, light." (p. 158) While not infallible, the natural sciences are society's one great engine for producing objective knowledge about the world, not just one knowledge system among many, and certainly not a socially constructed reflection of contemporary dominant ideology. Dawkins accepts that science cannot say what we should accept and reject, "but does not think of values as a special kind of fact that can be studied non-scientifically", notwithstanding that values are a kind of fact that anthropologists can and do study. "Least of all does he think religion has any special authority on values." (p. 158) Gould's perspective is more ambiguous, in which some important questions are outside the scope of science, falling into the domain of religion. "On this issue, Dawkins' views are simple. He is an atheist | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,900 |
Dawkins vs. Gould Theisms of all varieties are just bad ideas about how the world works, and science can prove that those ideas are bad. What is worse, as he sees it, these bad ideas have mostly had socially unfortunate consequences." (pp. 158–159) In contrast, Gould thought theism is irrelevant to religion. "He interprets religion as a system of moral belief. Its essential feature is that it makes moral claims on how we ought to live. In Gould's view, science is irrelevant to moral claims. Science and religion are concerned with independent domains." (p. 159) Sterelny considers Gould's views on religion "doubly strange". (p. 159) First, various religions make innumerable factual claims about the history of the world and how it works, and those claims are often the basis of moral injunctions. Second, Gould's conception of ethics seems strange. "Does he think that there are genuine ethical truths? Is there genuine moral knowledge?" (p. 159) Recent ethical thinking has two approaches to this question, with perhaps the main contemporary argument being the 'expressivist' view that moral claims express the speaker's attitude towards some act or individual. In this view "when, for instance, I call someone a scumbag, I do not describe a particular moral property of that person. Rather, I express my distaste for that person and their doings." (pp. 159–160) The main alternative is 'naturalism', in which moral claims are based on facts, albeit complex, about human welfare. Gould seems to deny both options | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,901 |
Dawkins vs. Gould "If 'expressivism' is right, there is no independent domain of moral knowledge to which religion contributes", with moral utterances reflecting not objective features of the world, but attitudes and opinions of the speakers. Conversely, "if naturalism is right, science is central to morality. For it discovers conditions under which we prosper." (p. 159) Gould thinks that there are important domains of human understanding where science has no role, and moreover he is sceptical about science's role within its 'proper' domain. Nevertheless, he rejects extreme versions of postmodern relativism. Evolution is an objective fact, containing objective facts, and those facts are not just aspects of a Western creation myth reflecting the dominant ideology, or an element of the current palaeontological paradigm. "So "to some extent" Gould shares with Dawkins the view that science delivers objective knowledge about the world as it is." (p. 161) But while science reflects objective evidence and is not a mere socio-cultural construction "Gould argues that science is very deeply influenced by the cultural and social matrix in which it develops", (p. 161) with many of his writings illustrating the influence of social context on science, and its ultimate sensitivity to evidence. These writings "began as reflections on natural history; they ended as reflections on the history of natural history". (p | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,902 |
Dawkins vs. Gould 161) Gould's Time's Arrow, Time's Cycle (first published in 1987) "locates the development of our conception of deep history in its cultural and intellectual context without any suggestion that that cultural context perverted the development of geology", whereas "in Wonderful Life, Gould argued that the Burgess Shale fauna were misunderstood because they were interpreted through the ideology of their discoverer". (p. 162) The Mismeasure of Man is Gould's most famous work on the themes of socio-cultural interests leading to bad science, pseudo-science, racist and sexist science, where "a particular ideological context led to a warped and distorted appreciation of the evidence on human difference". (p. 162) Thus, "one sharp contrast between Dawkins and Gould is on the application of science in general, and evolutionary biology in particular, to our species". (p. 162) Yet paradoxically, Dawkins' most systematic writings on human evolution explore the differences between human evolution and that of most other organisms, in which humans pass on their values through ideas and skills which Dawkins calls memes. To Dawkins, ideas are often like pathogens or parasites, replicating throughout human populations, sometimes quite virulently, with evangelical religion being a salient example. Doubts about the reliability and accuracy of idea replication suggest Dawkins' own view of cultural evolution may not work | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,903 |
Dawkins vs. Gould But his general approach has gained some popularity, as illustrated by works which explore the interaction between cultural and biological evolution, such as Peter Richerson and Robert Boyd's "Not By Genes Alone". as well as Eytan Avital and Eva Jablonka's" Animal Traditions". "So though Dawkins approaches human behaviour using different tools to those of standard sociobiologists and evolutionary psychologists, he is fully committed to the idea that we can understand ourselves only in an evolutionary framework." (pp. 164–165) This contrasts with Gould. While "Of course" he accepts that humans are an evolved species, "Everything that Gould does not like in contemporary evolutionary thinking comes together in human sociobiology and its descendant, evolutionary psychology. The result has been a twenty-year campaign of savage polemic against evolutionary theories of human behaviour. Gould "hates" sociobiology". And "It is true that some evolutionary psychology does seem simple-minded," such as Randy Thornhill's "unconvincing" attempt to argue that a tendency towards rape is an evolutionary adaptation. (p. 165) However, contemporary evolutionary psychologists, and especially biological anthropologists, have accepted the need for caution in testing adaptationist hypotheses. (p. 165) However, even the most disciplined sociobiological approaches reflect different approaches to evolution to that exemplified by Gould | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,904 |
Dawkins vs. Gould They "tend not to emphasise the importance of development and history in imposing constraints on adaptation, the problems in translating microevolutionary change into species-level change, the role of contingency and mass extinction in reshaping evolving lineages, or the importance of paleobiology to evolutionary biology", (p. 166) which likely played a part in Gould's hostility. But Sterelny suspects more most of all, Gould thought "these ideas are dangerous and ill-motivated as well as wrong. They smack of hubris, of science moving beyond its proper domain, and incautiously at that". Conversely, to Dawkins, knowledge of evolutionary underpinnings to human behaviour is potentially liberating, and "might even help us to escape the poisoned chalice of religion". (p. 166) Finally, in chapter 13, Sterelny summarises the fundamental contrasts between the views of Dawkins and Gould. In Dawkins' argument, selection acts on lineages of replicators, which are mostly but not exclusively genes. Ideas and skills are the replicators in animals capable of social learning, and "the earliest replicators were certainly not genes". (p. 167) Genetic competition occurs through vehicle-building alliances, with selection dependent on repeatable influences on those vehicles. Other genetic replication strategies include Outlaws, the prospects of which are enhanced at the expense of vehicle adaptiveness. And extended phenotype genes advantageously enhance their environment | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,905 |
Dawkins vs. Gould The vehicles of Dawkins replicators need not be individuals, but can also be groups, although animal co-operation is not sufficient to claim group selection. Evolution's central explanatory imperative is the existence of complex adaptation, which can only be explained by natural selection. This complex adaptation evolves gradually, with occasional replication errors resulting in large but survivable phenotypic change. Humans are unusual species in that they are vehicles for memes as well as genes, although humans are not exempt from evolutionary biological explanations. Extrapolationism is a sound working theory, with most evolutionary patterns the result of microevolutionary change over vast geological time. Major animal lineages are the result of ordinary speciation processes, although possibility-expanding changes may result in some form of lineage-level selection. In contrast, Gould sees selection as usually acting on organisms in a local population, although in theory and practice, it can occur at many levels, with change at one level often affecting future options at other levels. Selection can occur at the group level, with some species lineages having characteristics which make extinction less likely, or speciation more likely. And while rare, selection can occur on genes within an organism. While selection is important, and requires understanding, it is just one of many factors explaining microevolutionary events and macroevolutionary patterns | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,906 |
Dawkins vs. Gould Further, complex adaptations are but one phenomenon explanations in evolutionary biology. Extrapolationism is not a good theory, with large-scale patterns in the history of life not explainable by extrapolating from measurable events in local populations. Evolutionary biology needs a theory of variation, explaining the effect of variation supply on change potentiality. While humans are evolved animals, attempts to explain human behaviour using techniques from evolutionary biology have largely failed, "vitiated by one-sided understanding of evolutionary biology. They have often been biologically naive." (p. 170) Sterelny notes that these debates remain alive and developing, with no final adjudication possible as yet. "But we can say something about how the argument has developed." (p. 170) He claims that "the idea that gene-selectionist views of evolution are tacitly dependent on reductionism and genetic determinism is a mistake. Dawkins and the other gene selectionists do not think that nothing happens in evolution but changes in gene frequency." (p. 170) They do not deny the significance of the organism or phenotype, which they see as vehicles of selection, or 'survival machines', which interact with other survival machines and with the environment in ways replication of the genes whose vehicles they are. But there are other replication-enhancing strategies apart from organism construction | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,907 |
Dawkins vs. Gould Extended phenotypes, as exemplified by parasitic species, are common and important, with probably all parasitic gene pools including "genes whose adaptive effects are on host organisms." (p. 171) And "the outlaw count is unknown, but it is growing all the time", and may transpire to be more common than thought. Sterelny notes that "gene selectionism is not determinism. No gene selectionist thinks that there is typically a simple relationship between carrying a particular gene and having a particular phenotype". While they exist, such as the sickle-cell haemoglobin gene, they are the exception not the rule. Gene-selectionist ideas are compatible with context dependence of gene action, but they do assume some reasonable regular relationship between a specific gene in an organism's genotype, and some aspect of the organism's phenotypic expression. They assume that within gene lineages, the effect on their vehicles will be fairly similar. "So while gene selectionists are not genetic determinists, they are making a bet on developmental biology. When revitalised to reoccurring features of context, gene action will turn out to be fairly systematic. There is no reason to suppose that this hunch is false, but it is not known to be true." (p. 172) Developmental biology is relevant to this debate in another important way: "The role of selection in evolution | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,908 |
Dawkins vs. Gould Gould is betting that when the facts of developmental biology are in, it will turn out that the evolutionary possibilities of most lineages are highly constrained", with some characteristics "frozen" into their respective lineages. "They are developmentally entrenched. That is, these basic organisational features are connected in development to most aspects of the organism's phenotype, and that makes them hard to change." (p. 172) And "since variation in these frozen-in features is unlikely, selection is not likely to be important in explaining their persistence", (p. 173) and Gould thinks 'frozen accidents' are important in explanations of evolutionary patterns found in the fossil record. Conversely, Dawkins thinks that over time, selection can alter the range of a lineage's evolutionary possibilities. "So he thinks both that selection has a larger range of variation with which to work, and that when patterns do exist over long periods ... selection will have played a stabilising role." (p. 173) The integration of evolution and development "is the hottest of hot topics in contemporary evolutionary theory, and this issue is still most certainly open" | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,909 |
Dawkins vs. Gould In discussing the effects of mutations, Sterelny's "best current guess is that developmental biology probably does generate biases in the variation that is available to selection, and hence that evolutionary trajectories will often depend both on selection and these biases in supply" (173), vindicating Gould's view that developmental biology is crucial to explaining evolutionary patterns. (p. 174) "But it is harder to see how to resolve some of Gould's other claims about the large-scale history of life. Despite the plausibility of the distinction between disparity and diversity, we are not close to constructing a good account of disparity and its measurement". (p. 174) Further, convergent evolution belies the unpredictability that Gould supposes. However, "most examples of convergence are not independent of evolutionary experiments. For they concern lineages with an enormous amount of shared history, and hence shared developmental potential", as in "the standard example of streamlining in marine reptiles, sharks, pelagic bony fish like the tuna, and dolphins". (p. 175) Further, "the scale is not large enough. The fact that eyes have often evolved does not show that had, say, the earliest chordates succumbed to a bit of bad luck (and become extinct), then vertebrate-like organisms would have evolved again." (p. 175) Moreover, Gould's main concern is not with adaptive complexes, which are the source of the above, oft-cited examples, "but with body plans—basic ways of assembling organisms | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,910 |
Dawkins vs. Gould " Sterelny thinks that "we have to score Gould's contingency claims as: 'Don't know; and at this stage don't know how to find out'". (p. 175) Gould seems right that mass extinctions played a role in shaping evolutionary history, and "is probably right that extinction works by different rules in mass extinction regimes". (p. 176) Some ideas are difficult to assess, such as whether mass extinctions filter out the features of species or of individuals comprising species. It is also difficult to tell how fundamental is the disagreement between Gould and Dawkins on this. But Sterelny's bet is that Gould may be right in thinking that survival or extinction in mass extinction depends on species properties. "However, it has proved hard to find really clear, empirically well-founded examples to back up this hunch." (p. 176) It was once thought that sexual reproduction was maintained by species selection, which Sterelny outlines. He notes however that "this idea has recently fallen on hard times", with new individual-based ideas being developed. Further, species-level maintenance of sexual reproduction "has a problem: sex does not always promote evolvability", breaking up as well as creating advantageous gene combinations. (p. 177) "So it has been hard to find really convincing examples of species-level properties that are built by species-level selection | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,911 |
Dawkins vs. Gould The problem is to find: (i) traits that are aspects of species, not the organisms making up the species; (ii) traits that are relevant to extinction and survival; and (iii) traits that are transmitted to daughter species, granddaughter species and so forth". And "transmission to daughter species is especially problematic". (p. 177) In the end, Sterelny states his own views are much closer to Dawkins than to Gould's, especially regarding microevolution—change within local populations. "But macroevolution is not just microevolution scaled up; Gould's paleontological perspective offers real insights into mass extinction and its consequences, and, perhaps, the nature of species and speciation". And Gould is considered right to expand the explanatory agenda of evolutionary biology to include large-scale patterns in life's history. "So, Dawkins is right about evolution on local scales, but maybe Gould is right about the relationship between events on a local scale, and those on the vast scale of paleontological time." (p. 178) The Suggested Reading section for each chapter is an extension of the chapter, aimed at pointing the reader in the direction of material that may assist their understanding of the issues under discussion | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,912 |
Dawkins vs. Gould This section of Sterelny's book contains, chapter by chapter, a comprehensive list of recommended reading, covering all of the main publications by Dawkins, Gould, and their respective proponents, along with many lesser-known publications by them, with accompanying commentary on either the authors, the publications, or both. Also, the readability of the various publications, and the relevance of the publications to the issues under discussion, as well as the relationship of the publications to each other, such as authors responding to each other through their publications, or supporting the stance of other authors, etc. He also tries to further clarify some points in the process. | Biology | https://en.wikipedia.org/wiki?curid=18244814 | Dawkins vs. Gould | 139,913 |
Morley Kare Dr. Morley Richard Kare (1922–1990) was a physiologist and biologist. Morley Richard Kare was born in 1922 in Winnipeg, Manitoba. He received his bachelor's degree in agriculture from the University of Manitoba in 1943, his master’s in nutrition from the University of British Columbia in 1948 and his Ph.D. in physiology from Cornell University in 1952. Dr. Kare taught physiology at Cornell University, North Carolina State University and the University of Pennsylvania. Although his early research focused on muscle biochemistry and metabolism, he became increasingly interested in the senses of taste and smell and how these senses contribute to nutrition and food choice across species. Kare is best remembered for founding the Monell Chemical Senses Center, a multidisciplinary basic research institute devoted to the science of taste and smell, located in Philadelphia, Pennsylvania. He served as the Center’s first Director from 1968 until his death in 1990, at which point Dr. Gary Beauchamp took over. In his memory, the Monell Center created the Morley R. Kare Fellows Fund in 1990. The Fund helps support scientists beginning careers in the chemical senses. | Biology | https://en.wikipedia.org/wiki?curid=18247348 | Morley Kare | 139,914 |
Spore (2008 video game) Spore is a 2008 life simulation real-time strategy God game developed by Maxis, published by Electronic Arts and designed by Will Wright, and was released for Microsoft Windows and Mac OS X. Covering many genres including action, real-time strategy, and role-playing games, "Spore" allows a player to control the development of a species from its beginnings as a microscopic organism, through development as an intelligent and social creature, to interstellar exploration as a spacefaring culture. It has drawn wide attention for its massive scope, and its use of open-ended gameplay and procedural generation. Throughout each stage, players are able to use various creators to produce content for their games. These are then automatically uploaded to the online Sporepedia and are accessible by other players for download. "Spore" was released after several delays to generally favorable reviews. Praise was given for the fact that the game allowed players to create customized creatures, vehicles and buildings. However, "Spore" was criticized for its gameplay which was seen as shallow by many reviewers; GameSpot remarked: "Individual gameplay elements are extremely simple". Controversy surrounded "Spore" due to the inclusion of SecuROM, and its digital rights management software, which can potentially open the user's computer to security risks | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,915 |
Spore (2008 video game) "Spore" allows the player to develop a species from a microscopic organism to its evolution into a complex animal, its emergence as a social, intelligent being, to its mastery of the planet and then finally to its ascension into space, where it interacts with alien species across the galaxy. Throughout the game, the player's perspective and species change dramatically. The game is broken up into distinct "stages". The outcome of one phase affects the initial conditions and leveling facing the player in the next. Each phase exhibits its own style of play, and has been described by the developers as ten times more complicated than its preceding phase. Phases often feature optional missions; when the player completes a mission, they are granted a bonus, such as a new ability or money. If all of a player's creations are completely destroyed at some point, the species will be respawned at its nearest colony or at the beginning of the phase. Unlike many other Maxis games, "Spore" has a primary win condition, which is obtained by reaching a supermassive black hole placed at the center of the galaxy and receiving a "Staff of Life". However, the player may continue to play after any goal has been achieved. The first four phases of the game, if the player uses the editors only minimally, will take up to 15 hours to complete, but can take as little as one or two hours. Note that there is no time limit for any stage: the player may stay in a single stage as long as they wish, and progress to the next stage when ready | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,916 |
Spore (2008 video game) At the end of each phase, the player's actions cause their creature to be assigned a characteristic, or consequence trait. Each phase has three consequence traits, usually based on how aggressively or peacefully the phase was played. Characteristics determine how the creature will start the next phase and give it abilities that can be used later in the game. "Spore" is a game that is separated into stages, each stage presenting a different type of experience with different goals to achieve. The five stages are the Cell Stage, the Creature Stage, the Tribal Stage, the Civilization Stage, and the Space Stage. Once the primary objective is completed, the player has the option to advance to the next stage, or continue playing the current stage. The Cell Stage (sometimes referred to as the tide pool, cellular, or microbial stage) is the very first stage in the game, and begins with a cinematic explanation of how the player's cell got onto the planet through the scientific concept of panspermia, with a meteor crashing into the ocean of a planet and breaking apart, revealing a single-celled organism. The player guides this simple microbe around in a 3D environment on a single 2D plane, reminiscent of Flow, where it must deal with fluid dynamics and predators, while eating meat chunks or plants. The player may choose whether the creature is a herbivore or a carnivore prior to starting the stage | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,917 |
Spore (2008 video game) The player can find "meteor bits" (apparently from the aforementioned panspermic meteor) or kill other cells to find parts that upgrade their creature by adding abilities such as electricity, poison or other parts. Once the microbe has found a part, the player can call a mate to enter the editor, in which they can modify the shape, abilities and appearance of the microbe by spending "DNA points" earned by eating meat chunks or plants in the stage. The cell's eating habits in the Cell Stage directly influence its diet in the Creature Stage, and only mouths appropriate to the diet (Herbivore, Carnivore, or Omnivore) established in the Cell Stage will become available in the Creature Stage. Once the creature "grows" a brain and the player decides to progress to the next stage, the creature editor appears, prompting the user to add legs before the shift to land. The Creature editor differs in that it gives the player the ability to make major changes to the creature's body shape and length, and place parts in three-dimensional space instead of a top-down view as in the Cell editor. In the Creature Stage, the player creates their own land creature intended to live on a single continent. If the player attempts to swim to another island, an unidentified monster eats the player, and the player is warned not to come again. The biosphere contains a variety of animal species which carnivorous and omnivorous creatures can hunt for food, and fruit-bearing plants intended for herbivores and omnivores | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,918 |
Spore (2008 video game) The player creature's Hunger becomes a measured stat as well as its Health in this stage; depletion of the Hunger meter results in Health depletion and eventual death of the player creature unless food is eaten. In the Creature Stage, the player has a home nest where members of their own species are located. The nest is where the player respawns following death, and acts as a recovery point for lost HP. Other species' nests are spread throughout the continent. While interacting with them, the player can choose to be "social" or "aggressive"; how the player interacts with other creatures will affect their opinion of the player's species. For instance, by mimicking their social behaviors (singing, dancing etc.), NPC creatures will eventually consider the player an ally, but if the player harms members of their species, they will flee or become aggressive upon sighting them. The player can heal in allied nests and add allied creatures to their packs. "Epic" creatures, which are rare, aggressive creatures more than twenty times the player's height, feature prominently in the Creature Stage. The player cannot use social interactions with an Epic creature. There are also "Rogue" creatures which may be befriended or attacked. Additionally, spaceships may appear in this stage and abduct a creature | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,919 |
Spore (2008 video game) Progress in the Creature Stage is determined by the player's decisions on whether to befriend or attack other species, and to which degree; these decisions will affect the abilities of the player's species in subsequent stages of the game. Successful socialization and hunting attempts will give DNA Points, which may be spent on many new body parts. The player will also be rewarded with multiple DNA points for allying with or completely extincting a species. Placing new parts in the Creature editor comes at the expense of DNA points; more expensive parts will further upgrade the player creature's abilities for either method of interaction, as well as secondary abilities such as flight, speed or boosted health. After the player is finished editing, a newly evolved generation of creatures will be present in the home nest as the player's creature hatches. As the player's creature befriends or hunts more creatures, its intelligence and size increases until it is able to form a tribe. After the brain of the player's species evolves sufficiently, the species may enter the Tribal Stage. The species' design becomes permanent, and the player sheds control of an individual creature in favor of the entire tribe group, as the game focuses on the birth of division of labor for the species. The player is given a hut, a group of fully evolved creatures, as well as two of six possible Consequence Abilities, unlocked depending on the species' behavior in the previous phases | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,920 |
Spore (2008 video game) This is only possible if the player played the previous stages; if the player started directly from the "Galaxy Screen", they are locked. Gameplay during this stage is styled as an RTS. Rather than controlling one creature, the player now controls an entire tribe and can give them commands such as gathering food, attacking other tribes or simply moving to a certain location. The player may give the tribe tools such as weapons, musical instruments, and healing or food-gathering implements. Food now replaces "DNA points" as the player's currency, and can be spent on structures and additional tribe members, or used to appease other tribes. Tribe members also gain the option to wear clothes, the editing of which replaces the Creature Editor in the 'Tribal Outfitter'. Combat can be made more effective with weapons like stone axes, spears, and torches. For socializing, a player can obtain musical instruments: wooden horns, maracas and didgeridoos. Miscellaneous tools can be used for fishing and gathering food and for healing tribe members. All tools, however, require a specialized tool shack, which costs food to build. Tribe members can also gather food, an essential concept. Food can be stolen by wild creatures or by other tribes in the form of raids. The diet choice that the player made in prior stages, whether herbivore, omnivore, or carnivore, determines what food the tribe can gather and eat. Animals can be hunted for meat, and fish or seaweed can be speared for food | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,921 |
Spore (2008 video game) Fruit is gathered from trees and bushes, and players can also domesticate animals for eggs, which all diet types can eat. Any foreign animals in the player's pack in the Creature Stage are automatically added to the tribe as farm animals. Epic creatures may threaten nests or tribes. Allied tribes will occasionally bring the player gifts of food. Players can steal food from other tribes (though it angers them), and dead tribes may be pillaged for their food. There are five other tribes that appear along with the player's tribe. For every tribe befriended or destroyed, a piece of a totem pole is built, which may increase the population limit of the player's tribe or grant access to new tools and clothes. When all five tribes are allied or conquered, the player may move forward to the Civilization Stage. The events of Tribal Stage have left the player's tribe the dominant species of the planet, but the species itself has now fragmented into many separate nations. The player retains control of a single nation with one city. The goal in the civilization phase is to gain control of the entire planet, and it is left to the player to decide whether to conquer it using military force, diplomacy, or religious influence. Two new editors (the building and vehicle editors) are used to create city buildings and vehicles. The player can place three types of buildings (House, Factory, and Entertainment) around the City Hall (which can also be customized) and may build up to 3 types of vehicles (sea, land and air) at each city | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,922 |
Spore (2008 video game) These vehicles serve military, economic or religious purposes. The main unit of currency is "Sporebucks", which is used to purchase vehicles and buildings. To earn income, players can capture spice geysers and set up spice derricks at their locations, conduct trade, or build factories. In constructing vehicles and buildings, as with most real-time strategy games, there is a capacity limit; building houses will increase the cap, and constructing various buildings adjacent to one another will provide a productivity bonus or deficit. The presence of other nations requires the player to continue expanding their empire using military force, propaganda, or simply buying out cities. Players can choose their method of global domination depending on the types of cities they own. Military states grow solely by attacking other cities. Nations with a religious trait construct special missionary units that convert other cities via religious propaganda. Likewise, economic states communicate solely by trade and have no weapons (except for defensive Turrets). If the player's nation captures a city of a different type, they can choose to have the city retain its original type if they wish, or convert it to match the type it was captured with. Players of all three ideological paths can eventually use a superweapon, which requires a large number of cities and Sporebucks, but gives the player a significant advantage over rival nations. Aside from enemy nations, Epic creatures may threaten individual cities | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,923 |
Spore (2008 video game) The Space Stage provides new goals and paths as the player's species begins to spread through the galaxy. The game adopts the principle of mediocrity, as there are numerous forms of life scattered throughout the galaxy. The player controls a single spaceship, built at the beginning of the Space Stage. The player can travel by clicking on other planets and moons and stars, though each jump costs energy. Later in the game, the player can purchase a wormhole key which enables them to travel through black holes, offering instant transportation to a sister black hole. There are around 500,000 planets in the game's galaxy orbiting around 100,000 stars (including Earth and its star, Sol). Players can make contact with other space-faring civilizations, or "empires", which sport many different personalities and worldviews, ranging from diplomatic and polite species willing to ally, to distrustful, fanatical empires more willing to wage war. Completing missions for an empire improves the player's relationship with them, as does trading and assisting in fending off attacks. When the player has become allied with an empire, they can ask certain favors of the empire. If the player becomes enemies with an empire, they will send a small fleet of ships to attack the player's ship as soon as they enter their territory | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,924 |
Spore (2008 video game) One of the main goals in the Space Stage is for the player to push their way toward a supermassive black hole at the galaxy's center, which introduces the game's final antagonists, the Grox, a unique species of cybernetic aliens with a powerful empire of 2400 systems surrounding the core. Getting to the center of the galaxy and entering starts a cinematic in which the player is introduced to Steve. After the cinematic dialogue with Steve ends the player is shot out of the black hole, and gets rewarded with the Staff of Life. Another major goal in the game was to eradicate the Grox, which yielded an achievement. Several other stages were mentioned at various points by the developers, including a Molecular Stage, an Aquatic Stage, a City Stage, and a Terraforming Stage. Ultimately, these were scrapped. If Galactic Adventures is installed, the player may be given missions which involve travelling to planets, beaming down and completing Maxis-created, planetside 'adventures'. With this expansion, the player can also outfit their Captain with weapons and accessories which assist in these adventures. The occupants of allied ships can also take part. User-generated content is a major feature of "Spore"; there are eighteen different editors (some unique to a phase). All have the same general UI and controls for positioning, scaling and colouring parts, whether for the creation of a creature, or for a building or vehicle | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,925 |
Spore (2008 video game) The Creature editor, for example, allows the player to take what looks like a lump of clay with a spine and mould it into a creature. Once the torso is shaped, the player can add parts such as legs, arms, feet, hands, noses, eyes, and mouths. Many of these parts affect the creature's abilities (speed, strength, diet, etc.), while some parts are purely decorative. Once the creature is formed, it can be painted using a large number of textures, overlays, colours, and patterns, which are procedurally applied depending on the topology of the creature. The only required feature is the mouth. All other parts are optional; for example, creatures without legs will slither on the ground like a slug or an inchworm, and creatures without arms will be unable to pick up objects. There are two new editors seen in the new expansion : these include the captain editor (also called the captain outfitter) and the adventure creator, which enables terraforming and placing objects freely on adventure planets. "Spore" user community functionality includes a feature that is part of an agreement with YouTube granting players the ability to upload a YouTube video of their creatures' activity directly from within the game, and EA's creation of "The "Spore" YouTube Channel", which will showcase the most popular videos created this way. In addition, some user-created content will be highlighted by Maxis at the official "Spore" site, and earn badges of recognition | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,926 |
Spore (2008 video game) One of "Spore's" most social features is the "Sporecast", an RSS feed that players can use to subscribe to the creations of any specific "Spore" player, allowing them to track their creations. There is a toggle which allows the player to restrict what downloadable content will be allowed; choices include: "no user generated content", "official Maxis-approved content", "downloadable friend content", and "all user-created content". Players can elect to ban content in-game, at any time, and Maxis monitors content for anything deemed inappropriate, issuing bans for infractions of content policy. "Spore" has also released an API (application programming interface) to allow developers to access data about player activity, the content they produce and their interactions with each other. The "Spore" API is a collection of RESTful public web services that return data in .XML format. In April 2009, the results of the "Spore" API Contest was concluded with winners building interactive visualizations, games, mobile applications and content navigation tools. The API also includes a Developers forum for people wishing to use all the creations people have made to create applications. The game is referred to as a "massively single-player online game" and "asynchronous sharing." Simultaneous multiplayer gaming is not a feature of "Spore" | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,927 |
Spore (2008 video game) The content that the player can create is uploaded automatically to a central database, cataloged and rated for quality (based on how many users have downloaded the object or creature in question), and then re-distributed to populate other players' games. The data transmitted is very small — only a couple of kilobytes per item transmitted – due to procedural generation of material. Via the in-game "MySpore Page", players receive statistics of how their creatures are faring in other players' games, which has been referred to as the "alternate realities of the "Spore" metaverse." The game reports to the player on how other players have interacted with him or her. For example, the game reports how many times other players have allied with the player's species. The personalities of user-created species are dependent on how the user played them. Players can share creations, chat, and roleplay in the Sporum, the game's internet forum hosted by Maxis. Multiple sections allow forum users to share creations and tips for the game, as well as roleplay. The "Sporepedia" keeps track of nearly every gameplay experience, including the evolution of a creature by graphically displaying a timeline which shows how the creature incrementally changed over the eons; it also keeps track of the creature's achievements, both noteworthy and dubious, as a species. The "Sporepedia" also keeps track of all the creatures, planets, vehicles and other content the player encounters over the course of a game | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,928 |
Spore (2008 video game) Players can upload their creations to Spore.com to be viewed by the public at the "Sporepedia" website. The ever-growing list of creations made by players is past the 100 million mark so far. "Spore" uses procedural generation extensively in relation to content pre-made by the developers. Wright mentioned in an interview given at E3 2006 that the information necessary to generate an entire creature would be only a couple of kilobytes, and went on to give the following analogy: "think of it as sharing the DNA template of a creature while the game, like a womb, builds the 'phenotypes' of the animal, which represent a few uploaded and downloaded freely and quickly from the "Sporepedia" online server. This allows users to asynchronously upload their creations and download other players' content, which enriches the experience of the game as more of its players progress in the game." IGN Australia awarded "Spore" a 9.2 out of 10 score, saying, "It ["Spore"] will make you acknowledge just how far we've come, and just how far we have to go, and "Spore" will change the way you think about the universe we live in." "PC Gamer" UK awarded the game a 91%, saying ""Spore"s triumph is painfully ironic. By setting out to instill a sense of wonderment at creation and the majesty of the universe, it's shown us that it's actually a lot more interesting to sit here at our computers and explore the contents of each other's brains." In its 4 | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,929 |
Spore (2008 video game) 5 (of 5) -star review, GameSpy wrote ""Spore" is a technological triumph that introduces a whole new way of tapping into a bottomless well of content." Most of the criticism of "Spore" came from the lack of depth in the first four phases, summarized by Eurogamer's 9 of 10 review, which stated, "for all their mighty purpose, the first four phases of the game don't always play brilliantly, and they're too fleeting." 1UP.com reasoned in its B+ graded review, "It's not a perfect game, but it's definitely one that any serious gamer should try." GameSpot in its 8.0 of 10 review called "Spore" "a legitimately great game that will deliver hours of quality entertainment", but criticized the "individual gameplay elements [that] are extremely simple." Jason Ocampo's IGN 8.8 of 10 review stated, "Maxis has made an impressive product that does so many incredible things" but added, "while "Spore" is an amazing product, it's just not quite an amazing game." "The New York Times "review of "Spore" mostly centered on lack of depth and quality of gameplay in the later phases of the game, stating that "most of the basic core play dynamics in "Spore" are unfortunately rather thin | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,930 |
Spore (2008 video game) " While a review in "PC Gamer" US stated that "it just isn't right to judge "Spore" in the context of so many of the other games we judge", "Zero Punctuation" was also critical of the game, claiming it did not live up to the legacy of "The Sims": "The chief failing of "Spore" is that it's trying to be five games, each one a shallow and cut down equivalent of another game, with the Civilization Stage even going so far as to be named after the game ["Civilization"] it's bastardizing." Criticism has also emerged surrounding the stability of the game, with "The Daily Telegraph" stating: "The launch of "Spore", the keenly anticipated computer game from the creators of "The Sims", has been blighted by technical problems." In an interview published by MTV, "Spore" designer Will Wright responded to early criticism that the phases of the game had been dumbed-down by explaining "We were very focused, if anything, on making a game for more casual players. "Spore" has more depth than, let’s say, "The Sims" did. But we looked at the Metacritic scores for "Sims 2", which was around ninety, and something like "Half-Life", which was ninety-seven, and we decided — quite a while back — that we would rather have the Metacritic and sales of "Sims 2" than the Metacritic and sales of "Half-Life"". In its first three weeks on sale, the game sold 2 million copies, according to Electronic Arts | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,931 |
Spore (2008 video game) It received a "Silver" sales award from the Entertainment and Leisure Software Publishers Association (ELSPA), indicating sales of at least 100,000 copies in the United Kingdom. "Spore" uses a modified version of the controversial digital rights management (DRM) software SecuROM as copy protection, which requires authentication upon installation and when online access is used. This system was announced after the originally planned system met opposition from the public, as it would have required authentication every ten days. Additionally, EA released the game under a policy by which the product key of an individual copy of the game would only be authenticated on up to three computers; however, some users ran afoul of the limitations as the software would consider even a slight change of hardware to constitute a different computer, resulting in all authorizations being used up by those who often upgrade their computer. In response to customer complaints, this limit was raised to five computers. After the activation limit has been depleted, EA Customer Service will consider further activations on a case-by-case basis. A survey conducted by EA revealed that only 14% have activated on more than 1 PC and less than 1% of users have tried to activate "Spore" on more than 3 PCs. By September 14, 2008 (ten days after the game's initial Australian release), 2,016 of 2,216 ratings on Amazon gave the game one out of five stars, most citing EA's implementation of DRM for the low ratings | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,932 |
Spore (2008 video game) Electronic Arts cited "SecuROM" as a "standard for the industry" and Apple's iPod song DRM policy as justification for the control method. Former Maxis developer Chris Harris labeled the DRM a "screw up" and a "totally avoidable disaster". The "SecuROM" software was not mentioned on the box, in the manual, or in the software license agreement. An EA spokesperson stated that "we don't disclose specifically which copy protection or digital rights management system we use [...] because EA typically uses one license agreement for all of its downloadable games, and different EA downloadable games may use different copy protection and digital rights management.” A cracked version without the DRM was released two days before the initial Australian release, making "Spore" the most torrented game on BitTorrent in 2008. On September 22, 2008, a class action lawsuit was filed against EA, regarding the DRM in Spore, complaining about EA not disclosing the existence of SecuROM, and addressing how SecuROM runs with the nature of a rootkit, including how it remains on the hard drive even after "Spore" is uninstalled. On October 14, 2008, a similar class action lawsuit was filed against EA for the inclusion of DRM software in the free demo version of the Creature Creator. The DRM was also one of the major reasons why Spore is still one of the most pirated games to date, where within the first week of the game, over 500,000 people started downloading or downloaded it illegally from sites like The Pirate Bay | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,933 |
Spore (2008 video game) EA began selling "Spore" without SecuROM on December 22, 2008 through Steam. Furthermore, EA Games president Frank Gibeau announced that maximum install limit would be increased from 3 to 5 and that it would be possible to de-authorize and move installations to new machines, citing the need to adapt their policy to accommodate their legitimate customers. EA has stated, "By running the de-authorization tool, a machine 'slot' will be freed up on the online Product Authorization server and can then be re-used by another machine. You can de-authorize at any time, even without uninstalling Spore, and free up that machine authorization. If you re-launch "Spore" on the same machine, the game will attempt to re-authorize. If you have not reached the machine limitation, the game will authorize and the machine will be re-authorized using up one of the five available machines." However, the de-authorization tool to do this is not available on the Mac platform. In 2016, a DRM-free version of "Spore" was released on GOG.com. The educational community has shown some interest in using "Spore" to teach students about evolution and biology. However, the game's player-driven evolution mechanism differs from the theory of evolution in some key ways: In October 2008, John Bohannon of "Science" magazine assembled a team to review the game's portrayal of evolution and other scientific concepts. Evolutionary biologists T | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,934 |
Spore (2008 video game) Ryan Gregory of the University of Guelph and Niles Elredge of the American Museum of Natural History reviewed the Cell and Creature stages. William Sims Bainbridge, a sociologist from the U.S. National Science Foundation, reviewed the Tribe and Civilization stages. NASA's Miles Smith reviewed the Space Stage. The "Science" team evaluated "Spore" on twenty-two subjects. The game's grades ranged from a single A in galactic structure and a B+ in sociology to Fs in mutation, sexual selection, natural selection, genetics, and genetic drift. In addition, Yale evolutionary biologists Thomas Near and Thomas Prum found "Spore" fun to play and admired its ability to get people to think about evolutionary questions, but consider the game's evolutionary mechanism to be "severely messed up.". With this noted, study of how players make meaning with the game suggest that the game prompts more sophisticated thinking about evolution than the model the game presents. According to "Seed" magazine, the original concept for "Spore" was more scientifically accurate than the version that was eventually released. It included more realistic artwork for the single-celled organisms and a rejection of faster-than-light travel as impossible. However, these were removed to make the game more friendly to casual users | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,935 |
Spore (2008 video game) While "Seed" does not entirely reject "Spore" as a teaching tool, admiring its ability to show the user experimentation, observation, and scale, biological concepts did not fare so well: Will Wright argues that developers "put the player in the role of an intelligent designer" because of the lack of emotional engagement of early prototypes focusing on mutation. Intelligent design advocate Michael Behe of Lehigh University reviewed the game and said that "Spore" "has nothing to do with real science or real evolution—neither Darwinian nor intelligent design,". "Spore Creature Creator" is the creature creator element of "Spore" released prior to the full game. In late 2008, EA released the "Creepy and Cute" expansion pack, which includes new parts and color schemes for creature creation. Among the new parts were additional mouths and eyes, as well as "insect legs." The pack also included new test-drive animations and backgrounds. An expansion pack named "" was released on June 23, 2009. It allows the player's creature to beam onto planets, rather than using a hologram. It also adds an "Adventure Creator" which allows for the creation of missions and goals to share with the "Spore" community. Creatures can add new abilities, including weaponry, tanks, and crew members, as well as a section of the adventure creator that involves editing a planet and using 60 new flora parts. "Bot Parts" was an expansion part of an EA promotion with Dr | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,936 |
Spore (2008 video game) Pepper in early 2010, 14 new robotic parts for "Spore" creatures were released in a new patch (1.06.0000) available only from the Dr. Pepper website. Codes found on certain bottles of Dr Pepper allow the player to redeem these parts, albeit only for the USA, excluding Maine. It was only available for Windows PC, and was eventually extended to Canadian residents. The promotion ended in late 2011. The Spore Bot Parts Pack has caused controversy within the "Spore" community, because of many problems with the download and its exclusive nature. The Nintendo DS spinoff is titled "Spore Creatures", focusing on the Creature phase. The game is a 2D/3D story-based role-playing game as the gamer plays a creature kidnapped by a UFO and forced to survive in a strange world, with elements of "Nintendogs". Another "Spore" title for the DS called "Spore Hero Arena" was released in 2009. "Spore Origins" is the mobile phone/iPhone/iPod spinoff of "Spore", and as with the Nintendo DS version, focuses on a single phase of gameplay; in this case, the cell phase. The simplified game allows players to try to survive as a multicellular organism in a tide pool, similar to "Flow". The iPhone version takes advantage of the device's touch capabilities and 3-axis accelerometer. A Wii spinoff of the game now known as "Spore Hero" has been mentioned by Will Wright several times, such as in his October 26, 2007 interview with "The Guardian" | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,937 |
Spore (2008 video game) Buechner confirmed it, revealing that plans for a Wii version were underway, and that the game would be built from the ground up and would take advantage of the Wii Remote, stating, "We're not porting it over. You know, we're still so early in design and prototyping that I don't know where we're going to end up, so I don't want to lead you down one path. But suffice to say that it's being developed with the Wii controls and technology in mind." Eventually, a spin-off under the title "Spore Hero" was announced, an adventure game built ground up for the Wii with a heavier focus on evolution. For a time, Xbox 360 and PlayStation 3 versions of "Spore" were under consideration. Frank Gibeau, president of Electronic Arts' Games Label announced that the publisher might use the underlying technology of "Spore" to develop electric software titles, such as action, real-time strategy, and role-playing games for the PlayStation 3, Xbox 360, and Wii. "Spore Hero Arena" is a spinoff game for the Nintendo DS released on October 6, 2009. "Darkspore" was an action role-playing game that utilized the same creature-editing mechanics. It was released in April 2011 for Microsoft Windows. The game was shut down in March 2016. "Spore Creature Keeper" was a spin-off game developed by Maxis for Windows and OS X. Made for younger users, the gameplay was heavily based on "The Sims". Originally planned for a summer 2009 release, the game development was eventually cancelled | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,938 |
Spore (2008 video game) There is an iTunes-style ""Spore" Store" built into the game, allowing players to purchase external "Spore" licensed merchandise, such as t-shirts, posters, and future "Spore" expansion packs. There are also plans for the creation of a type of "Spore" collectible card game based on the "Sporepedia" cards of the creatures, buildings, vehicles, and planets that have been created by the players. There are also indications of plans for the creation of customized creature figurines; some of those who designed their own creatures at E3 2006 later received 3D printed models of the creatures they created. On December 18, 2008, it was announced that players could now turn their creations into 3D sculptures using Z Corporations 3D printing technology. The "Spore" Store also allows people to put their creatures on items such as T-shirts, mugs, and stickers. The "Spore" team worked with a comic creation software company to offer comic book versions of players' "Spore stories". Comic books with stylized pictures of various creatures, some whose creation has been shown in various presentations, can be seen on the walls of the "Spore" team's office. The utility was revealed at the on July 24, 2008 as the "Spore Comic Creator", which would utilize MashOn.com and its e-card software | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,939 |
Spore (2008 video game) "Spore: Galactic Edition", a special edition of the game; includes a "Making of Spore" DVD video, "How to Build a Better Being" DVD video by National Geographic Channel, "The Art of Spore" hardback mini-book, a fold-out "Spore" poster and a 100-page Galactic Handbook published by Prima Games. EA, 20th Century Fox, and AIG announced the development of a "Spore" film on October 1, 2009. The movie adaptation would be a CGI-animated film created by Blue Sky Studios. Chris Wedge was set to direct the proposed film. However, , the film remains in development hell. Cliff Martinez composed the main menu Galaxy theme track. Brian Eno created the generative music together with Peter Chilvers and is credited for the ”spore compositions”. "Solar System", "Timeline" and a few other tracks on Spore—"Religious Vehicle Editor". "Sporepedia" was composed by Saul Stokes. "Spore" has been used in academic studies to see how respondents display surrogation. | Biology | https://en.wikipedia.org/wiki?curid=18248185 | Spore (2008 video game) | 139,940 |
Milbemycin oxime/lufenuron The combination milbemycin oxime/lufenuron (trade names Sentinel Flavor Tabs, by Novartis Animal Health, and Program plus) is a parasite control drug in which the active ingredient, milbemycin oxime, eliminates worms, while a second active ingredient, lufenuron, arrests the development of eggs and larvae, preventing them from maturing and continuing the infestation of an animal. This combination is registered for animal use only. To achieve efficacy, the treatment is administered once monthly, together with food, in a dosage suitable for the weight of the affected animal. The usual ratio is 500 μg milbemycin oxime and 10 mg lufenuron/kg body weight. Novartis indicates the proper dosage by color-coding the packages. Several 2002 studies by Novartis demonstrate that milbemycin oxime/lufenuron compares favorably to some other treatments, such as the moxidectin injection. The combination is considered effective in the elimination of fleas, and the prevention of infection from hookworm ("Ancylostoma caninum"), heartworm ("Dirofilaria immitis"), roundworms, whipworms ("Trichuris vulpis"), and ascarids ("Toxocara canis" and "Toxascaris leonina"). The USA FDA approval for Sentinel says "Concurrent use of insecticides may be necessary". It is the concurrent use of Sentinel and nitenpyram (Capstar) that has an FDA-approved indication "to kill adult fleas". can lead to a negative physical response in some animals, most dangerously those that test positively for heartworm disease before receiving the treatment | Biology | https://en.wikipedia.org/wiki?curid=18248420 | Milbemycin oxime/lufenuron | 139,941 |
Milbemycin oxime/lufenuron Less serious side effects are an upset stomach or loss of appetite, various skin irritations, and mood changes. | Biology | https://en.wikipedia.org/wiki?curid=18248420 | Milbemycin oxime/lufenuron | 139,942 |
PBLU pBLU is a commercially produced bacterial plasmid that contains genes for ampicillin resistance (beta lactamase and beta galactosidase). It is often used in conjunction with an ampicillin-susceptible "E. coli" strain to teach students about transformation of eubacteria. It is 5,437 base pairs long. There is a multiple cloning site in the "lacZ" gene. | Biology | https://en.wikipedia.org/wiki?curid=18255533 | PBLU | 139,943 |
Combinatorial biology In biotechnology, combinatorial biology is the creation of a large number of compounds (usually proteins or peptides) through technologies such as phage display. Similar to combinatorial chemistry, compounds are produced by biosynthesis rather than organic chemistry. This process was developed independently by Richard A. Houghten and H. Mario Geysen in the 1980s. allows the generation and selection of the large number of ligands for high-throughput screening. techniques generally begin with large numbers of peptides, which are generated and screened by physically linking a gene encoding a protein and a copy of said protein. This could involve the protein being fused to the M13 minor coat protein pIII, with the gene encoding this protein being held within the phage particle. Large libraries of phages with different proteins on their surfaces can then be screened through automated selection and amplification for a protein that binds tightly to a particular target. | Biology | https://en.wikipedia.org/wiki?curid=18259841 | Combinatorial biology | 139,944 |
Improvision is a software developer based in Coventry, England. The company is the developer of Confocal, live cell imaging solutions and image analysis software for 2D, 3D and 4D imaging. was founded in 1990 by Ken Salisbury, Andrew Waterfall and John Zeidler. was acquired by PerkinElmer on 2 April 2007, in a cash transaction. The company is based in Coventry, England, and it develops and sells scientific imaging equipment and software including confocal microscopy systems and image analysis software (Volocity) for the Life Sciences industry. In 2004, was runner-up in the Apple Design Awards for Best Mac OS X Scientific Computing Solution for their Volocity 2.6.1 software release. In 2002, it was a winner in the annual Lord Stafford Awards for Innovation. In April 2000, received a Queen's Award for Enterprise, the highest honour which can be given to a UK company, in recognition of outstanding achievement in export sales. | Biology | https://en.wikipedia.org/wiki?curid=18263923 | Improvision | 139,945 |
Intron-encoded endonuclease I-SceI Intron-encoded endonuclease I-Sce I is a homing endonuclease. The enzyme is used in biotechnology as a meganuclease. It recognises an 18-base pair sequence TAGGGATAACAGGGTAAT and leaves a 4 base pair 3' hydroxyl overhang. It is a rare cutting endonuclease. Statistically an 18-bp sequence will occur once in every 6.9*10 base pairs (a frequency of 1 in 4). This sequence does not normally occur in a human or mouse genome. I-SceI is coded by introns. It is present in the mitochondria of yeast Saccharomyces cerevisiae. | Biology | https://en.wikipedia.org/wiki?curid=18267886 | Intron-encoded endonuclease I-SceI | 139,946 |
Allion Healthcare () was the parent company of MOMSpharmacy based in Melville, New York primarily known for providing mail order HIV medications to patients who are primarily on Medicaid or the AIDS Drug Assistance Program (ADAP). Among the offerings is the MOMSPak in which the drugs are packed together in dated individual packages to make the multi-drug regimen easier. The company reported having 15,610 patients in 2007. The company has distribution centers in New York, California, Florida, New Jersey, and Washington. The company was founded in 1983 as The Care Group and changed its name to Allion in 1999 after emerging from bankruptcy. The company has an agreement with Roche Laboratories for pricing discounts in exchange for providing blind patient data on Fuzeon medication. In November 2007 Company signed an exclusive distribution agreement with Galea Life Sciences for Nutraplete, the first therapeutic dietary supplement designed specifically for people living with HIV/AIDS. The company was listed on NASDAQ on the ticker symbol ALLI. On January 13, 2010 the company closed on being acquired by the private equity firm HIG Capital for $6.60/share in a deal valued at $278 million. On April 4, 2012, the New York Attorney General Eric T. Schneiderman charged four people associated with the company in a Money Laundering & Bribery Scheme claiming the company sold blackmarket drugs "of unknown origin and potency, and in some cases, drugs that were mislabeled or potentially expired | Biology | https://en.wikipedia.org/wiki?curid=18277696 | Allion Healthcare | 139,947 |
Allion Healthcare " According to the complaint: To date none of such has been proven. The indictment said at least $155 million in false claims were associated with the charge. | Biology | https://en.wikipedia.org/wiki?curid=18277696 | Allion Healthcare | 139,948 |
Group Selection (book) Group Selection is a 1971 book edited by George C. Williams, containing papers written by biologists arguing against the view of group selection as a major force in evolution. The group of biologists writing on a single unified (if somewhat broad) theme contrasts with Williams' earlier seminal 1966 book "Adaptation and Natural Selection", whose arguments Williams suspected to be his alone. In particular it contains a reprint, with an erratum, of W.D. Hamilton's classic 1964 paper on inclusive fitness, "The Genetical Evolution of Social Behavior" plus a paper by John Maynard Smith entitled "The Origin and Maintenance of Sex" (pp 163–175), containing ideas on evolution of sex later developed by Maynard Smith; see especially his 1978 book "The Evolution of Sex". | Biology | https://en.wikipedia.org/wiki?curid=18290237 | Group Selection (book) | 139,949 |
Genetically modified mouse A genetically modified mouse or genetically engineered mouse model (GEMM) is a mouse ("Mus musculus") that has had its genome altered through the use of genetic engineering techniques. Genetically modified mice are commonly used for research or as animal models of human diseases, and are also used for research on genes. Together with patient-derived xenografts (PDXs), GEMMs are the most common "in vivo" models in cancer research. Both approaches are considered complementary and may be used to recapitulate different aspects of disease. GEMMs are also of great interest for drug development, as they facilitate target validation and the study of response, resistance, toxicity and pharmacodynamics. In 1974 Beatrice Mintz and Rudolf Jaenisch created the first genetically modified animal by inserting a DNA virus into an early-stage mouse embryo and showing that the inserted genes were present in every cell. However, the mice did not pass the transgene to their offspring, and the impact and applicability of this experiment were, therefore, limited. In 1981 the laboratories of Frank Ruddle from Yale University, Frank Costantini and Elizabeth Lacy from Oxford, and Ralph L. Brinster and Richard Palmiter in collaboration from the University of Pennsylvania and the University of Washington injected purified DNA into a single-cell mouse embryo utilizing techniques developed by Brinster in the 1960s and 1970s, showing transmission of the genetic material to subsequent generations for the first time | Biology | https://en.wikipedia.org/wiki?curid=18293050 | Genetically modified mouse | 139,950 |
Genetically modified mouse During the early eighties, Palmiter and Brinster developed and led the field of transgenesis, refining methods of germline modification and using these techniques to elucidate the activity and function of genes in a way never possible before their unique approach. There are two basic technical approaches to produce genetically modified mice. The first involves pronuclear injection into a single cell of the mouse embryo, where it will randomly integrate into the mouse genome. This method creates a transgenic mouse and is used to insert new genetic information into the mouse genome or to over-express endogenous genes. The second approach, pioneered by Oliver Smithies and Mario Capecchi, involves modifying embryonic stem cells with a DNA construct containing DNA sequences homologous to the target gene. Embryonic stem cells that recombine with the genomic DNA are selected for and they are then injected into the mice blastocysts. This method is used to manipulate a single gene, in most cases "knocking out" the target gene, although increasingly more subtle and complex genetic manipulation can occur (e.g. humanisation of a specific protein, or only changing single nucleotides). Genetically modified mice are used extensively in research as models of human disease. Mice are a useful model for genetic manipulation and research, as their tissues and organs are similar to that of a human and they carry virtually all the same genes that operate in humans | Biology | https://en.wikipedia.org/wiki?curid=18293050 | Genetically modified mouse | 139,951 |
Genetically modified mouse They also have advantages over other mammals, in regards to research, in that they are available in hundreds of genetically homogeneous strains. Also, due to their size, they can be kept and housed in large numbers, reducing the cost of research and experiments. The most common type is the knockout mouse, where the activity of a single (or in some cases multiple) genes are removed. They have been used to study and model obesity, heart disease, diabetes, arthritis, substance abuse, anxiety, aging and Parkinson disease. Transgenic mice generated to carry cloned oncogenes and knockout mice lacking tumor suppressing genes have provided good models for human cancer. Hundreds of these oncomice have been developed covering a wide range of cancers affecting most organs of the body and they are being refined to become more representative of human cancer. The disease symptoms and potential drugs or treatments can be tested against these mouse models. A mouse has been genetically engineered to have increased muscle growth and strength by overexpressing the insulin-like growth factor I (IGF-I) in differentiated muscle fibers. Another mouse has had a gene altered that is involved in glucose metabolism and runs faster, lives longer, is more sexually active and eats more without getting fatter than the average mouse (see Metabolic supermice). Great care should be taken when deciding how to use genetically modified mice in research | Biology | https://en.wikipedia.org/wiki?curid=18293050 | Genetically modified mouse | 139,952 |
Genetically modified mouse Even basic issues like choosing the correct "wild-type" control mouse to use for comparison are sometimes overlooked. | Biology | https://en.wikipedia.org/wiki?curid=18293050 | Genetically modified mouse | 139,953 |
List of instruments used in anatomy Instruments used in Anatomy dissections are as follows: | Biology | https://en.wikipedia.org/wiki?curid=18311517 | List of instruments used in anatomy | 139,954 |
Hematology-Oncology and Stem Cell Transplantation Research Center The Hematology-Oncology Research Center and Stem Cell Transplantation (HORCSCT; formerly HORCBMT) is affiliated to Tehran University of Medical Sciences (TUMS) and based in Shariati Hospital, Tehran, Iran. As a main national hematology-oncology center, it is among the most prominent stem cell transplantation centers in the world, with more than 300 successful transplantations performed per year. The Center is mainly involved in new therapeutic approaches which are developed or under development for hematologic-oncologic patients, particularly stem cell transplantation. In addition, it is involved in the research activities aimed at improving the diagnosis and management of different hematologic and oncologic diseases. The Center was founded in 1991 by Professor Ardeshir Ghavamzadeh, who is currently the Center director. It was further expanded in 2000, when it was moved to a new 4800 m building well-equipped for different basic and clinical research and services. Iran will invest 2.5 billion dollars in the country's stem cell research over the next five years (2008-2013). | Biology | https://en.wikipedia.org/wiki?curid=18311730 | Hematology-Oncology and Stem Cell Transplantation Research Center | 139,955 |
Connectomics is the production and study of connectomes: comprehensive maps of connections within an organism's nervous system, typically its brain or eye. Because these structures are extremely complex, methods within this field use a high-throughput application of neural imaging and histological techniques in order to increase the speed, efficiency, and resolution of maps of the multitude of neural connections in a nervous system. While the principal focus of such a project is the brain, any neural connections could theoretically be mapped by connectomics, including, for example, neuromuscular junctions. This study is sometimes referred to by its previous name of hodology. One of the main tools used for connectomics research at the macroscale level is diffusion MRI. The main tool for connectomics research at the microscale level is chemical brain preservation followed by 3D electron microscopy, used for neural circuit reconstruction. Correlative microscopy, which combines fluorescence with 3D electron microscopy, results in more interpretable data as is it able to automatically detect specific neuron types and can trace them in their entirety using fluorescent markers. To see one of the first micro-connectomes at full-resolution, visit the Open Connectome Project, which is hosting several connectome datasets, including the 12TB dataset from Bock et al. (2011). Aside from the human brain, some of the model systems used for connectomics research are the mouse, the fruit fly, the nematode "C. elegans", and the barn owl | Biology | https://en.wikipedia.org/wiki?curid=18314899 | Connectomics | 139,956 |
Connectomics By comparing diseased connectome and healthy connectomes, we should gain insight into certain psychopathologies, such as neuropathic pain, and potential therapies for them. Generally, the field of neuroscience would benefit from standardization and raw data. For example, connectome maps can be used to inform computational models of whole-brain dynamics. Current neural networks mostly rely on probabilistic representations of connectivity patterns. Connectograms (circular diagrams of connectomics) have been used in traumatic brain injury cases to document the extent of damage to neural networks. The human connectome can be viewed as a graph, and the rich tools, definitions and algorithms of the Graph theory can be applied to these graphs. Comparing the connectomes (or braingraphs) of healthy women and men, Szalkai et al. have shown that in several deep graph-theoretical parameters, the structural connectome of women is significantly better connected than that of men. For example, women's connectome has more edges, higher minimum bipartition width, larger eigengap, greater minimum vertex cover than that of men. The minimum bipartition width (or, in other words, the minimum balanced cut) is a well-known measure of quality of computer multistage interconnection networks, it describes the possible bottlenecks in network communication: The higher this value is, the better is the network. The larger eigengap shows that the female connectome is better expander graph than the connectome of males | Biology | https://en.wikipedia.org/wiki?curid=18314899 | Connectomics | 139,957 |
Connectomics The better expanding property, the higher minimum bipartition width and the greater minimum vertex cover show deep advantages in network connectivity in the case of female braingraph. Human connectomes have an individual variability, which can be measured with the cumulative distribution function, as it was shown in . By analyzing the individual variability of the human connectomes in distinct cerebral areas, it was found that the frontal and the limbic lobes are more conservative, and the edges in the temporal and occipital lobes are more diverse. A “hybrid” conservative/diverse distribution was detected in the paracentral lobule and the fusiform gyrus. Smaller cortical areas were also evaluated: precentral gyri were found to be more conservative, and the postcentral and the superior temporal gyri to be very diverse. The human genome project initially faced many of the above criticisms, but was nevertheless completed ahead of schedule and has led to many advances in genetics. Some have argued that analogies can be made between genomics and connectomics, and therefore we should be at least slightly more optimistic about the prospects in connectomics. Others have criticized attempts towards a microscale connectome, arguing that we don't have enough knowledge about where to look for insights, or that it cannot be completed within a realistic time frame. Eyewire is an online game developed by American scientist Sebastian Seung of Princeton University | Biology | https://en.wikipedia.org/wiki?curid=18314899 | Connectomics | 139,958 |
Connectomics It uses social computing to help map the connectome of the brain. It has attracted over 130,000 players from over 100 countries. | Biology | https://en.wikipedia.org/wiki?curid=18314899 | Connectomics | 139,959 |
Fungivore Fungivory or mycophagy is the process of organisms consuming fungi. Many different organisms have been recorded to gain their energy from consuming fungi, including birds, mammals, insects, plants, amoebas, gastropods, nematodes, bacteria and other fungi. Some of these, which only eat fungi, are called fungivores whereas others eat fungi as only part of their diet, being omnivores. Many mammals eat fungi, but only a few feed exclusively on fungi; most are opportunistic feeders and fungi only make up part of their diet. At least 22 species of primate, including humans, bonobos, colobines, gorillas, lemurs, macaques, mangabeys, marmosets and vervet monkeys are known to feed on fungi. Most of these species spend less than 5% of the time they spend feeding eating fungi, and fungi therefore form only a small part of their diet. Some species spend longer foraging for fungi, and fungi account for a greater part of their diet; buffy-tufted marmosets spend up to 12% of their time consuming sporocarps, Goeldi’s monkeys spend up to 63% of their time doing so and the Yunnan snub-nosed monkey spends up to 95% of its feeding time eating lichens. Fungi are comparatively very rare in tropical rainforests compared to other food sources such as fruit and leaves, and they are also distributed more sparsely and appear unpredictably, making them a challenging source of food for Goeldi’s monkeys. Fungi are renowned for their poisons to deter animals from feeding on them: even today humans die from eating poisonous fungi | Biology | https://en.wikipedia.org/wiki?curid=18320085 | Fungivore | 139,960 |
Fungivore A natural consequence of this is the virtual absence of obligate vertebrate fungivores, with the diprotodont family Potoridae being the major exception. One of the few extant vertebrate fungivores is the northern flying squirrel, but it is believed that in the past there were numerous vertebrate fungivores and that toxin development greatly lessened their number and forced these species to abandon fungi or diversify. Many terrestrial gastropod mollusks are known to feed on fungi. It is the case in several species of slugs from distinct families. Among them are the Philomycidae (e. g. "Philomycus carolinianus" and "Phylomicus flexuolaris") and "Ariolimacidae" ("Ariolimax californianus"), which respectively feed on slime molds (myxomycetes) and mushrooms (basidiomycetes). Species of mushroom producing fungi used as food source by slugs include milk-caps, "Lactarius" spp., the oyster mushroom, "Pleurotus ostreatus" and the penny bun, "Boletus edulis". Other species pertaining to different genera, such as "Agaricus", "Pleurocybella" and "Russula", are also eaten by slugs. Slime molds used as food source by slugs include "Stemonitis axifera" and "Symphytocarpus flaccidus". Some slugs are selective towards certain parts or developmental stages of the fungi they eat, though this behavior varies greatly. Depending on the species and other factors, slugs eat only fungi at specific stages of development. Moreover, in other cases, whole mushrooms can be eaten, without any trace of selectivity | Biology | https://en.wikipedia.org/wiki?curid=18320085 | Fungivore | 139,961 |
Fungivore In 2008, "Euprenolepis procera" a species of ant from the rainforests of South East Asia was found to harvest mushrooms from the rainforest. Witte & Maschwitz found that their diet consisted almost entirely of mushrooms, representing a previously undiscovered feeding strategy in ants. Several beetle families, including the Erotylidae, Endomychidae, and certain Tenebrionidae also are specialists on fungi, though they may eat other foods occasionally. Other insects, like fungus gnats and scuttle flies, utilize fungi at their larval stage. Feeding on fungi is crucial for dead wood eaters as this is the only way to acquire nutrients not available in nutritionally scarce dead wood. Jays ("Perisoreus") are believed to be the first birds in which mycophagy was recorded. Canada jays ("P. canadensis"), Siberian jays ("P. infaustus") and Oregon jays ("P. obscurus") have all been recorded to eat mushrooms, with the stomachs of Siberian jays containing mostly fungi in the early winter. The ascomycete, "Phaeangium lefebvrei" found in north Africa and the Middle East is eaten by migrating birds in winter and early spring, mainly be species of lark (Alaudidae). Bedouin hunters have been reported to use "P. lefebvrei" as bait in traps to attract birds. The ground-foraging Superb Lyrebird "Menura novaehollandiae" has also been found to opportunistically forage on fungi. Fungi are known to form an important part of the diet of the southern cassowary ("Casuarius casuarius") of Australia | Biology | https://en.wikipedia.org/wiki?curid=18320085 | Fungivore | 139,962 |
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