Tree of life not real (Introduction)

by David Turell , Sunday, February 16, 2014, 15:35 (3911 days ago) @ dhw

TONY: My point is we do not have this gradual progression from less complex to more complex. Where complex creatures exist, they exist, with no obvious reliable precursors, and they exist alongside simpler forms already existed and did not grow significantly more complex. At least, we have no definitive evidence that one creature grew into a more complex one, only speculation. I am asking what happens to this train of thought if we remove the speculation about one organism metamorphosing into another organism, something which we have no definitive observations of, and simply look at the evidence for what it actually is instead of what we want it to be? Would our perception about the whole thing change?
> 
> dhw: The alternative which I presume you have in mind is separate creation. "Definitive evidence" is perhaps the key expression here. We have no definitive evidence for - or observation of - any form of life that does not descend from existing organisms (disregarding the very first living organisms, about whose origin we know nothing and therefore speculate endlessly). The observation that life descends from life is the basis of "common descent", which in turn is the basis of evolution. The alternative to one organism metamorphosing into another organism has to be not just one original form of life but billions. Even if I put on my theist hat, I would find it hard to believe that God would go to all the trouble of specially creating billions of forms the majority of which literally came to a dead end.-The answer to this debate may lie in the following paper which shows that new species arrive fully developed, without precursors, and then modify just a litle, Darwin predicted a cone, Gould an inverted mushroom, and the current paper a cylinder with little diversification.-http://phys.org/news/2013-07-scientific-evolution.html-As an aside, dhw has fallen into the trap I warn about: the second bolded comment assumes an anthropomorphized God who thinks like we do. For shame!-The first (in order) bolded statement is an assumption which is not supported from the evolution we see. The issue of common descent is what we are debating. We may descend from somewhat simple (the first cells) to very complex, but it is by huge jumps, by a mechanism we have not discovered. For me it suggests theistic evolution as everyone here knows.