The Theory of Evolution Is Valid

I. The Nested Hierarchy of SpeciesBasically, the argument of the nested hierarchy of species is this - species that are more like each other will have more similar genetic composition than those who are less like each other. This has been observed from the prokaryote to the primate group. Here is an illustation of this: "Most existing species can be organized rather easily in a nested hierarchical classification. This is evident in the use of the Linnaean classification scheme. Based on shared derived characters, closely related organisms can be placed in one group (such as a genus), several genera can be grouped together into one family, several families can be grouped together into an order, etc. .. Most importantly, the standard phylogenetic tree and nearly all less inclusive evolutionary phylogenies have statistically significant, high values of hierarchical structure. "[1][2]The empirical evidence for this idea is staggering. Consider this chart here: "One widely used measure of cladistic hierarchical structure is the consistency index (CI). .. As an example, a CI of 0.2 is expected from random data for 20 taxa. A value of 0.3 is, however, highly statistically significant. Most interesting for the present point is the fact that a CI of 0.1 for 20 taxa is also highly statistically significant, but it is too low—it is indicative of anti-cladistic structure. Klassen et al. took 75 CI values from published cladograms in 1989 (combined from three papers) and noted how they fared in terms of statistical significance. The cladograms used from 5 to 49 different taxa (i. e. different species). Three of the 75 cladograms fell within the 95% confidence limits for random data, which means that they were indistinguishable from random data. All the rest exhibited highly statistically significant values of CI. None exhibited significant low values; none displayed an anti-correlated, anti-hierarchical pattern. .. Seventy-five independent studies from different researchers, on different organisms and genes, with high values of CI (P < 0.01) is an incredible confirmation with an astronomical degree of combined statistical significance . "[1][3][4]Overall, the cladistic hierarchical structure of every species on Earth pretty much proves evolution. In no other biological system could any sort of hierarchy exist. Other theories would result in a plethora of species that have no apparent relationship; in other words, its a more choatic system than what exists on Earth. II. Past HistoryOn it's most simple level, evolution can be shown in bacteria: "This process of natural selection resulting in evolution can be easily demonstrated over a 24 hour period in a laboratory Petri dish of bacteria living in a nutrient medium. When a lethal dose of antibiotic is added, there will be a mass die-off. However, a few of the bacteria usually are immune and survive. The next generation is mostly immune because they have inherited immunity from the survivors. That is the case with the purple bacteria in the Petri dishes shown below--the bacteria population has evolved. " Natural selection is shown because those bacteria with traits that allow them to survive are still alive, and inevitably reproduce to allow for more immune bacteria[5]: II. A. VestigialalityVestigal structures are, simply, just characteristics that serve little or no function in the current species, but once did serve a major purpose. They would prove evolution because if an animal has a charateristic that it no longer needs in the present, it obviously evolved. One example is that in some blind species, rudimentary eyes exist. "Many cave dwelling animals, such as the fish Astyanax mexicanus (the Mexican tetra) and the salamander species Typhlotriton spelaeus and Proteus anguinus, are blind yet have rudimentary, vestigial eyes The eyes of the Mexican tetra have a lens, a degenerate retina, a degenerate optic nerve, and a sclera, even though the tetra cannot see. The blind salamanders have eyes with retinas and lenses, yet the eyelids grow over the eye, sealing them from outside light. "[1][6][10]Another example is the ostrich wing. "For example, wings are very complex anatomical structures specifically adapted for powered flight, yet ostriches have flightless wings. The vestigial wings of ostriches may be used for relatively simple functions, such as balance during running and courtship displays—a situation akin to hammering tacks with a computer keyboard. The specific complexity of the ostrich wing indicates a function which it does not perform, and it performs functions incommensurate with its complexity. " The ostrich wing is related to the wings of many other birds, but serves a little, non-flight function. [1]II. B. AtavismsAn atavism is closely related to a vestigiality. "An atavism is the reappearance of a lost character specific to a remote evolutionary ancestor and not observed in the parents or recent ancestors of the organism displaying the atavistic character. "[1]This is another prediction of evolution that has been observed many times: "Many famous examples of atavisms exist, including (1) rare formation of extra toes (2nd and 4th digits) in horses, similar to what is seen in the archaic horses Mesohippus and Merychippus, (2) atavistic thigh muscles in Passeriform birds and sparrows, (3) hyoid muscles in dogs, (4) wings in earwigs (normally wingless), (5) atavistic fibulae in birds (the fibulae are normally extremely reduced), (6) extra toes in guinea pigs and salamanders, (6) the atavistic dew claw in many dog breeds, and (7) various atavisms in humans. "[1][8]One semi-common example among humans is sketetal tails. While not common, they do exist, such as this one: "As with other atavistic structures, human tails are most likely the result of either a somatic mutation, a germline mutation, or an environmental influence that reactivates an underlying developmental pathway which has been retained, if only partially, in the human genome In fact, the genes that control the development of tails in mice and other vertebrates have been identified (the Wnt-3a and Cdx1 genes). As predicted by common descent from the atavistic evidence, these tail genes have also been discovered in the human genome. "[1][8][9]II. C. Common AnatomiesMany of the structures that we have are present in a multitude of species. For example, the embryo of most complex animals is pretty much the same: Or take the forelimb of the lion, bird, seal, and human. They all have the same basic strucutre in their limbs: On a related example, take the wings of certain animals. They all have the same commom structure: The fact that all of these structures are related hints at a common ancestor. There is no other way for that multitude of species to have all of those same characteristics. [7]II. D. RelatednessOne prime way to see evolution in action is to find different species that had a recent common ancestor. This means that the species being studied would be relatively alike. "If evolution has occurred, there should be many anatomical similarities among varieties and species that have diverged from a common ancestor. Those species with the most recent common ancestor should share the most traits. For instance, the many anatomical similarities of wolves, dogs, and other members of the genus Canis are due to the fact that they are descended from the same ancient canine species and still share 99.8% of their genes. Wolves and dogs also share similarities with foxes, indicating a slightly more distant ancestor with them. "[5]An easy way to look at this is to compare amino acids. "Biologists have found that the more closely related two species are, the greater the similarity in amino acid sequences of their proteins. Such comparisons allow scientists to deduce evolutionary relationships between various organisms. " Here is a chart showing how many different amino acids are between humans and a particular species: It is pretty easy to see that the species that we should share a lineage with (like chimpanzees) have fewer amino acid differences than species that we last had a lineage with around a billion years ago (like yeast). [5] Overall, all of this is proof of evolution because no other biological system could account of the common relatedness that many species share with each other. ConclusionThere are a lot of proofs of evolution, cheif among them the nested hierarchical struture of species and the many results of this. Evolution is a very well tested scientific theory that has made predictions that have been proven time and time again. It is nothing short of a very valid theory. Sources[1]: . http://www.talkorigins.org...;(Parts I-I and II-I & II)[2]: . http://www.ncbi.nlm.nih.gov...[3]: . http://www.ncbi.nlm.nih.gov...[4]: Fisher, R. A. (1990) Statistical methods, experimental design, and scientific inference. Bennet, J. H. ed. , Oxford: Oxford University Press. [5]: . http://anthro.palomar.edu...[6]: Jeffery, W. R. (2001) "Cavefish as a model system in evolutionary developmental biology. " Dev Biol. 231: 1-12. [7]: . http://www.citruscollege.edu...[8]: Hall, B. K. (1995) "Atavisms and atavistic mutations. " Nature Genetics 10: 126-127. [9]: Katoh, M. (2002) "Molecular cloning and expression of mouse Wnt14, and structural comparison between mouse Wnt14-Wnt3a gene cluster and human WNT14-WNT3A gene cluster. " Int J Mol Med 9 :221-227. [10]: Kos, M. , Bulog, B. , Szel, A. , and Rohlich, P. (2001) "Immunocytochemical demonstration of visual pigments in the degenerate retinal and pineal photoreceptors of the blind cave salamander Proteus anguinus. " Cell Tissue Res 303: 15-25. NOTE: Sources 2-4, 6, and 8-10 were quoted from source 1.