Tree of life not real (Introduction)

by dhw, Monday, February 17, 2014, 11:12 (3934 days ago) @ David Turell

dhw: [to Tony:] 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.-DAVID: 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 little... -http://phys.org/news/2013-07-scientific-evolution.html-QUOTE: "Co-author Dr Sylvain Gerber, added: "A key question now is what prevents groups from generating fundamentally new forms later on in their evolution. Equally intriguing is the manner in which some groups are able to break free from these constraints.-"Our results hint that this may hinge upon the evolution of new 'key innovations' that enable groups to exploit new resources or habitats, for example dinosaurs growing feathers and evolving wings or fish evolving legs and moving onto land to claim new territory."-(Tony has also quoted the first sentence, but left out the rest, which changes the whole meaning.)-Of course innovations are the key to the evolution of new species, and they would probably not survive if they did not work! This does not mean that new species arrive fully developed without precursors, but that existing organisms change their nature (break free from their constraints), whereas others remain as they were. This is a perfectly conventional view of evolution!-DAVID: 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!-So it's not anthropomorphic for you to read God's mind and endow him with an anthropocentric purpose, but it's anthropomorphic for me to question the logic of the arguments you present to justify your anthropocentric hypothesis. For shame!-DAVID: 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.-Common descent does not preclude jumps (hence punctuated equilibrium, and the proposal that innovations must work at once if they are to survive). It merely tells us that all living organisms descended from earlier living organisms. The fact that we have not discovered the mechanism does not invalidate the theory, or lend tangible support to theism. We have all seen life descending from earlier life. Has anyone seen life that did not descend from earlier life?