Whale Evolution in the Fossil Record

Thanks for your opening argument. Usually you state the premise or resolution for the debate so the voters know how to determine a winner. I will state that there is no demonstrable evidence of whale evolution having taken place. I must point out that it seems your line of reasoning is that these "whale ancestors" or "cousins" are related because of homologous structures which is to me a very weak argument. Homology of any kind is just as much evidence of a common Designer as it is for common ancestry. I realize homology is important for evolution, especially when studying fossil creatures which you wish to "fit" in the tree of evolution, but it is not a very strong argument. Homology can be evidence for either a common Designer or a common ancestor depending on the model of origins being applied. I will make an argument against your position under the following subtitles.A Mechanism for EvolutionSo first off, for your model of origins (in the case of cetaceans) to even be considered viable, you must have a demonstrable mechanism for evolutionary change. Unless you can provide a mechanism which has demonstrably shown to add new genetic information and to form novel structures (such as a blowhole or flipper), then your "interpretation" of the fossils of Pakicetus, Ambulocetus, Remingtonocetus, etc., cannot be taken seriously. Pakicetus This first example you give as a candidate for a transitional form in the whale evolution series falls far short of your intended aspirations. You point out "transitional" structures which are homologous to cetaceans and artiodactyles, yet you fail to point out that Pakicetus was entirely a land dwelling mammal. "A prominent whale expert, Thewissen, and colleagues unearthed some more bones of Pakicetus, and published their work in the journal Nature. The commentary on this paper in the same issue says, "All the postcranial bones indicate that pakicetids were land mammals, and . . . indicate that the animals were runners, with only their feet touching the ground'" (http://creation.com...). In a detailed analysis of the semicircular canal systems in both living and fossil cetaceans, it was demonstrated that a sharp gap in relative sizes between whales and non-whales existed, including the pakicetid Ichthyolestes. There were no examples of slow and gradual shrinking of the canals in any of the fossil series, they were either one relative size or the other. In fact, the paper affirms that the alleged change in canal structure happened ‘instantaneously’ and produced a ‘unique’ apparatus (Spoor F., Bajpai S., Hussain S.T., Kumar K. and Thewissen J.G.M., Vestibular evidence for the evolution of aquatic behaviour in early cetaceans, Nature 417(6885):163–166, 9 May 2002). It is a huge jump to say Pakicetus evolved into modern whales, or to even say it is related as a "cousin." Lets move one. Remingtonocetus I'm afraid your evidence here is just to circumstantial. Your assuming whale evolution has taken place, and you are interpreting these homologous structures as evidence. Marsupial moles and placental moles are nearly identical, yet since evolutionists say these evolves separately and are not closely related to each other, the phenomena is categorized as "convergent evolution." So I am supposed to accept you three homologous structures as evidence for Remingtonocetus being ancestrally related to modern whales when marsupial and placental moles share nearly 100% of their morphology yet they are unrelated. Homology is selectively used in the story of evolution and is therefore untrustworthy. Ambulocetus You yourself admitted that two key "evidential bones" of Ambulocetus were missing, so I'm not following your reasoning here. If the sigmoid process and semi-circular canals are supposed to be striking evidence of whale kinship, why bring up Ambulocetus? Homology As already stated, homology does not provide conclusive evidence of evolution as it is model-dependant evidence. Furthermore, it has been demonstrated that homologous structures are in many cases not derived from homologous genes (http://creation.com...). Genetic research has not shown that homologous structures are produced by homologous genes and follow homologous patterns of embryological development (http://creation.com...). So how do you know that these similarities are based on homologous genes if these are mere fossils with no DNA information to study? And how can you say that these cases of homologous structures are not examples of convergent evolution rather than evidence of ancestral relationship? Conclusion So far all you have demonstrated are a few fossil creatures which share a few structures with cetaceans. I can show many more structures shared between Chimpanzees and humans, that doesn't ultimately "prove" we share a common ancestor. Your evidence so far is very weak and very circumstantial. I look forward to your response and I am prepared to defend my statements. On to you...