Here are some of the arguments given in support of the theory of universal common descent, aka the theory of evolution, from multiple threads in this forum. They span several years of posting. Some had links from scientific studies, others were asserted from memory. - e.coli have evolved to a different species - Neanderthal is a separate species - Horse tree is proof of evolution - Whales are common with equus and canadae and proves evolution - Vestigial organs prove we have evolved - the 'tail' in the embyo shows we came from a fish - archaeopteryx is a transitional species between bird & reptile - Time proves evolution. Given enough time, anything is possible - Fruit flies prove evolution Here is a summary of my responses. - e.coli are the same species, that have adapted to digest citrates - Neanderthal was a tribe of humans, & their dna is evident in living humans now. - The mtDNA in equus can be traced, & descendancy evidenced for some haplogroups, but many speculative 'horse ancestors' are just speculative. There is no evidence that they descended. That is believed, only. - Just because you can imagine a sequence of drawings, does not provide evidence that it happened. There is no evidence, genetic or otherwise, that whales are ascended or descended from equus or canidae. - Almost all of the original 86 vestigial organs listed in the 1800s have been proven to be necessary, important organs in the human anatomy. They are NOT vestigial, just assumed, wrongly. - It is not a tail. It is a developing embryo. Any imagined similarity to a tail is a 'looks like!' fallacy. - There are multiple, conflicting theories about archaeopteryx. It is impossible to make a definitive statement about this extinct creature, that has much more evidence of it being a bird with claws & feathers. ..like many living birds do. - Time has no mechanism to affect major changes in the genome. There is nothing evidenced to support this claim. It is a belief, not a scientifically evidenced theory. - Fruit flies, even after millions of generations, remain fruit flies. They are of the same genotype. These can be looked up if a refreshment is needed. I have pointed out what i consider to be the 'central flaw' of the theory of universal common descent. It is a false equivalency between horizontal variability, that is observed in living organisms, and the extrapolation of common descent. ..macro vs micro, as it is commonly presented. It is the ASSUMED ability of organisms to change outside of their genetic parameters. All scientific experimentation conflicts with this assumption, as organisms can only vary within their genetic haplotypes.. they do not change in their basic genetic structure, but are hard wired to produce only what their genes supply. In this thread, i repeat my challenge for scientific evidence, for this theory, which has become a belief.. an impassioned religious belief.. as evidenced by the zeal, indignation, and emotion that the Defenders of UCD employ in what should be a dispassionate examination of scientific evidence. I know this topic attracts hecklers, religious bigots, and unscientifically minded True Believers in a worldview. Those who only want to disrupt and oppose open inquiry should be ignored and/or reported, so a thoughtful, intelligent debate can occur. So, if you have evidence, arguments, or rational rebuttals for this subject, i would love to hear them, and debate the merits of this theory of origins.