Theory of evolution

My opponent is a well-educated individual from Saudi Arabia, and I respect his opinion. However, it is incorrect and I aim to enlighten him and others who share creationist beliefs. ==Rebuttals== a) It is ‘just’ a theory This is a common argument used by creationists who do not understand what a theory is. In fact, according to Creation Ministries International—the leading creationist think tank—says that wording is incorrect. You should instead say you disbelieve the evidence, or something along those lines. However, in science, a theory is a “well-substantiated explanation of data” [1]. Therefore, to say it is ‘just’ a theory is like admitting evolution is a well-substantiated position within the scientific sphere. My opponent, therefore, must not say that it is ‘just’ a theory, and should rather explain why evolution is incorrect. b) Based on ideas This is, in part, correct. Evolution is based on ideas. However, isn’t religion also based on ideas? Therefore, merely because something contains ideas behind it does not mean it is incorrect. To say that evolution is not based on facts is totally incorrect. In fact, it is one of the most supported theories in scientific istory. Hopefully I will enlighten my opponent as to the vast array of evidence for the theory of evolution—and I am using the word ‘theory’ as it is used in science, not in popular culture. ==Case== a) Anatomical vestiges First, what is a vestige? A vestige is a structure which has lost all or most of its function in a given species. As the argument goes, they only are retained because of evolution. A very well-known example would be ostrich wings. Wings evolved in order to provide flight, however the ostrich cannot fly, still has them. If evolution didn’t exist, and it came about from a designer, he must have not been very intelligent (reminds me of Tyson’s “Stupid Design” talk). Therefore, the only reasonable explanation is that the ostrich evolved from something which could fly, and they have simply been retained and have not yet gone away. However, they are not vestigial because they are useless—they help the bird balance whilst running, for example. They are vestigial because they are useless as wings [2]. How does this prove evolution? They are remnants of change. If a God made these animals, they would not have useless parts. This can easily be explained by evolution, as these parts had a function in the past and do not have one now. Alexander Werth, Biologist, has noted that vestige are “artifacts of the progressive change that occurred over generations via natural selection” [3]. Just like clues at a crime scene. Although the knife is no longer being used to stab someone, it is left behind as evidence of a murder. It may no longer fulfill its purpose (to inflict harm), but it still offers evidence as to what did actually occur. Vestiges offer significant proof of evolution. b) Atavisms These are very similar to vestiges. An atavism is a reappearance related to past ancestors, not found in the parents or other close relatives. For example, a whale has been found with an actual leg on its body. This would not be from its parents or other close relatives, but has reappeared from its past ancestors (which were tiger-like animals on land). Carl Wieland, CEO of Answers in Genesis (a creationist think tank) and editor of creation magazine stated the whale with this atavism offers a “serious challenge to … [the] creation model” [4]. Evolution predicts atavisms. We know that whales had terrestrial ancestors based on the phylogenetic tree. This means that there is a possibility that mutant whales will occasionally develop atavisms from these terrestrial ancestors. Most of the legs found on whales were merely a few bones (femurs, tibia, etc. ) but a few had entire feet with complete digits. Further evidence comes from humans themselves. Some newborns are born with tails—indicating an ancestor with a tail, which again points to ape-like ancestors. Evidence indicates that humans lost their tales due to decreases in the Wnt-3a gene—a mutation which was put into the homo sapien genome [5]. This offers evidence to the fact is new borns are sometimes born with tails, that this mutation disappears. And the fact that humans—whose recent ancestors do not have tails—are born with tails indicates that we do, in fact, come from an ancestor which had a tale. c) Fossil record There is quite a complete record of dinosaur to bird transitional fossils. In fact, this record is so complete that there are no gaps! There are many fossils which indicate a transition, and in fact have prerequisites to feathers on their bodies (in some cases, actual feathers are expected to have existed! ) To name some of these fossils, to name a few, “Eoraptor, Herrerasaurus, Ceratosaurus, Allosaurus, Compsognathus, Sinosauropteryx, Protarchaeopteryx, Caudipteryx, Velociraptor, Sinovenator, Beipiaosaurus, Sinornithosaurus, Microraptor, Archaeopteryx, Rahonavis, Confuciusornis, Sinornis, Patagopteryx, Hesperornis, Apsaravis, Ichthyornis, and Columba, among many others” [6]. There is also an extensive fossil record for reptile to mammal transitions. Fossils from the Jurassic indicate a class of mammaliaforms, an extinct group of animals “more closely related to the living mammals than to nonmammaliaform cynodonts” have existed. These fossils show “evolutionary innovations in the ear region, the temporomandibular joint, and the brain vault” [7]. This means that there are significant transitional fossils between reptiles and mammals, indicating some form of evolution occurred from one point to the next. Although a common ancestor has not been identified, the connection between humans and ape-like creatures is strong and has reached “a consensus” amongst phylogenetic analysis’s [8]. Homo erectus, Cro-Magnon, Homo habilis, etc. all show direct ancestry to one common ancestor (which has yet to be identified). So far, at least 14 transitional ape to human fossils have been identified [9]. Whale evolution is considered the “one of the most compelling examples of macroevolutionary change in vertebrates”. It is also the “best documented examples of macroevolution in mammals” [10]. The evolution of whale heads are well documented. [10] As we can see, the nasal positions shifted, orbits changed, etc. In primitive land mammals, molars have 3 cusps. Two cheek side, one tongue side. Two early whales have similar teeth to that of these primitive land mammals, however as more whales evolved we see a reduction in crests and basins, as shown in the following figure. [10] Conclusion: Overall, the evidence I have presented shows a simple conclusion: the evidence for evolution is overwhelming, and in the words of a leading creationist, the evidence often offers a “serious challenge to … [the] creation model”. 1. . http://creation.com... 2. . http://www.talkorigins.org... 3. . http://www.evolution-outreach.com... 4. . http://www.talkorigins.org... 5. Although the study was on mice, it is suggested that the same process applies to humans. See, e. g. , . http://www.ncbi.nlm.nih.gov... 6. . http://www.talkorigins.org... 7. Zhe-Xi Luo; Alfred W. Crompton; Ai-Lin Sun. “A New Mammaliaform from the Early Jurassic and Evolution of Mammalian Characteristics,” Science, Vol. 292, No. 5521. (May 25, 2001), pp. 1535-1540. 8. Talk Origins, see 6. 9. See 6, however it seems as though even more have been discovered. I count at least 16 here (an interactive webpage, explains each of the groups in simple terms): . http://humanorigins.si.edu... 10. Thewissen, J. G. M. ; Bajpai, Sunil “Whale Origins as a Poster Child for Macroevolution,” Bioscience, Vol. 51, No. 12 (January 1, 2001), pp. 1037