More about how evolution works; stasis (Evolution)

by David Turell , Sunday, October 18, 2015, 15:19 (3322 days ago) @ dhw

dhw: Stasis doesn't need explaining. If organisms have reached what your author called an “optimal” state, they don't need to change. They will go on living until there is a change in conditions to which they are unable to adapt.
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> DAVID: Your statement is correct, if one makes the assumption that the Earth never changes, but it is changing all the time. We know that 90% of everything that ever lived is now extinct. So ancient forms that never change are most unusual.
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> dhw: I can't follow your argument. Earth's changes explain why 90% of species are extinct: they died when they couldn't adapt. Earlier you complained that my hypothesis didn't explain “broad evidence of stasis, such as 250 million years of unchanged trilobites or 70 million-year old unchanged coelacanths.” Dinosaurs ruled the earth for about 160 million years, but died out when they couldn't cope with new conditions. What is there to explain?-Aren't 'ancient forms that never change most unusual'? Of course trilobites and dinosaurs died out, but bacteria didn't through 'snowball' Earth, palm trees in the Arctic, ice ages, etc. To me this means certain organisms are not meant to die, but I forget, you don't want to look for purpose in evolution.
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> dhw: I am not implying that adaptation leads to speciation, but that the same mechanism may also exploit new conditions in order to create new structures that lead to improvement (and so to speciation). -That sentence runs in circles: 'not implying adaptation leads to speciation'....'and so to speciation'. -> 
> dhw: You keep repeating the same objection, and I keep repeating the same answer. The changes HAVE to be jumps (hence no fossils) or the organisms won't survive. According to my hypothesis Darwin was wrong: random mutations and gradualism are out: the intelligent cell communities cooperate to restructure organisms (just as they cooperate when organisms adapt) to find new ways of exploiting the existing environment. If the innovation doesn't work, it and the organism won't survive. -And my objection is the same. The gaps in the fossil record require the engineering of new forms so that all the new parts are coordinated in their functions. The whale series of eight or nine steps is a wonderful example of the impossibility of your thesis. Those 'intelligent cell communities' can just think of everything and make the jumps.