Evolution

Observations of Speciation A common argument against evolution is that speciation which is key in so called "marco evolution" has never been observed, of course in reality it has showing that evolution through artificial selection has produced speciation in drosophila pseudoobscura (a common fruit fly) [1]. This proves that at the very least environmental stimuli have the potential to direct the selection of random mutations in such a way that over successive generations adaption and then specialisation occurs, this by itself at least in a technical sense proves the existence of evolution which is merely adaption through descent with modification. Of course there have been other recorded examples of speciation observed in laboratory conditions [2] but that is mostly irrelevant as a single case example should be enough to prove my point and the example of drosophila pseudoobscura is the most famous. Human Ancestral Tree DNA evidence has confirmed that modern humans (homo sapiens) and homo neanderthalensis were able to interbreed probably in the middle east [3] proving that at least in technical terms they were subspcies of the same species at one point, possibly before further divergence on the part of the neanderthals. Furthermore DNA of the homo denisova species has been found in many people throughout Asia and Australasia particularly in Melanesians and Aboriginal Australians [4] showing again that there is infertility and therefore a quadripartite relationship between homo sapiens, homo neanderthalensis, homo denisova and what evolutionary theory postulates is the common ancestor of all three which again would likely be inter-fertile with the other three. This likely fourth inter-fertile species was found in the form of homo heidelbergensis which inhabited Africa, the middle east and Europe from 600,000 to 200,000 years ago and its relationship to the other 3 confirmed through DNA testing [5]. In addition two more important decendents of homo heidelbergensis can be found in the form of homo rhodesiensis [6] which was so close to both later homo sapiens and to homo heidelbergensis that it has often been mistaken for both making it one of the clearest transitional fossils at least as far as morphology goes. But then again there is another decendant of homo rhodesiensis called homo sapiens idaltu which is directly ancestral to the modern human population [7]. In additional direct ancestors of the original homo heidelbergensis have been found in the form of homo antecessor which lived 1,200,000 years ago to 800,000 years ago and was likely not inter-fertile with modern humans however due to its morphological similarities with homo heidelbergensis it has often been confused for such [8] however there were significant enough morphological differences for the same species to be confused with a previous species named homo ergaster or a seperate species derived thereof [9]. Regardless everyone within the feild agress that both homo heidelbergensis and homo antecessor were both derived from homo ergaster [10]. Homo egraster is clearly a much earlier homonid which many more morphological traits of apes than later humans although its close relationship with homo antecessor and heidelbergensis show that there may be potential inter-fertility in these. Homo egraster originates around 1.9 million years ago [11] which means that it overlaps with homo habilis, the species likely transitional between the homo genus and earlier australopithecines. However realistically the furthest back you can trace a single line of evolution (with admittedly a couple of minor disagreements about what goes where or what should be called what) within humans is to homo ergaster which is verified through genetic, morpholitical and phylogenetic evidence as well as relative dating showing a sequential pattern of evolution that could not reasonably be explained by any other theory. Phylogenetic evidence Carl Linnaeus set out to classify life into a number of different groups during the 18th century, he could not have believed in evolution since the first musings of evolutionary theory would occur nearly two decades after his death. Despite this when trying to classify life rather than resulting in a number of different categories Linnaeus ended up having to categorise life into a number of hierarchical groups creating a single hierarchy of life where for instance a lion is categorised into the genus panthera along with for instance jaguars and tigers. The lion and all other members of panthera are then categorised into the family of felidae along with all cats big and small. All felidea are then placed within the order of carnivora containing almost all carnivorous mammals. All carnivora are then placed into the class of mammalia along with all mammals (including humans). All of this of course is nested into the phylum of chordata containing everything with a backbone and all chordates are classed in with animalia which includes all chordates and all other animals which are then classed as one of the primary kingdoms of life. All of this was figured out by Linnaeus in the 18th century (although he did not include humans) producing what is commonly refereed to as the tree of life (for a diagram of the tree of life to see what I mean see source [12]). When this was cross referenced with 21st century genetic analysis it matches up more or less exactly (with a could of changes that needed to be made such as with bats) this shows that there is not only a taxonomic hierarchy established by morphology and physiology but also a genetic hierarchy which mirrors the previously established hierarchy. (for this section I can provide general sources but most of this is relatively general and so if my opponent wants to cross reference anything I have said wikipedia should do). This points to groups with genetic similarities within groups of genetic similarities and those themselves within groups of genetic similarity so on and so forth. This serves as evidence for evolution due to producing the branching tree pattern that would be expected in evolutionary theory showing each taxonomic group the likelyhood of common ancestry, this is difficult to explain with theories other than common ancestry through evolution. Indeed this is the same pattern that we see in the "genetic route" of languages [13] and with human haplogroups [14] both of which directly comparable to the theory of evolution based on the principle of common ancestory. Genetic Evidence We know the average rate at which mutations occur within specific circumstances and therefore roughly the rate of genetic drift and evolution by natural and sexual selection occur as a result of this by sequencing the DNA of various organisms it can be told both how genetically related they are to modern humans and how long ago they would have had to share a common ancestor under evolutionary theory. This can often be cross referenced with the fossil record for instance with the family Equidae which traced it back to north America 50 million years ago but the most compelling example encapsulated in a single paper I have been able to produce is that of the ancestry of modern chickens and other related birds seen here [15] where genetics and the fossil record are cross referenced. In addition as mentioned earlier in the human ancestry portion human genetic evidence has been used to show cross breeding with other types of humans and sequence their genes from there as well as match them to fossils of other homonids. Vestigial Organs Vestigial organs are often misunderstood as being organs that no longer have a purpose and can therefore be refuted by showing that the organs still have a purpose, instead all that needs to be the case for an organ to be vestigial is that it serves a purpose that it was not originally intended for or serves a purpose that was originally secondary. A key example of organs that are clearly vestigial are the arm/wing and claw of an emu, the arm having no meaningful muscles [16] and the claw [17] is attached to said arm/wing where it cannot be moved. This is of course easily explained by evolution given the presence of claws in very early species of birds such as Confuciusornis [18] although admittedly fossil evidence for the ancestors of the emu is rather scarce [18]. [1] http://www.jstor.org... [2] http://onlinelibrary.wiley.com...(SICI)1096-9888(199808)33:8%3C750::AID-JMS680%3E3.0.CO;2-1/full [3] http://news.nationalgeographic.com... [4] https://www.sciencedaily.com... [5] http://www.innovateus.net... [6] http://eol.org... [7] http://www.nature.com... [8] https://australianmuseum.net.au... [9] https://www.revolvy.com... [10] http://eol.org... [11] https://www.sciencedaily.com... [12] http://www.greennature.ca... [13] http://www.ancient.eu... [14] http://arslanmb.org... [15] http://journals.plos.org... [16] https://www.ncbi.nlm.nih.gov... [17] http://2.bp.blogspot.com... [18] http://www.ucmp.berkeley.edu...