More about how evolution works; stasis (Evolution)

by dhw, Saturday, October 17, 2015, 12:21 (3107 days ago) @ David Turell

dhw: I am suggesting that this [“scattershot”] history can be explained by the fact that some organisms adapt to changing conditions, others fail and so die out, and others find their own ways of exploiting new conditions and “complexifying", as dictated by their individual ability to master changing conditions, and not by some overriding anthropocentric purpose.-DAVID: And a large number never advance at all. They don't fit the Darwin proposal of adapt or die, which you are proposing.-This doesn't make sense to me. If conditions don't change, organisms don't need to adapt; if conditions change, either organisms can still cope, or they adapt, or they die (even if adaptation simply means migrating). Advancement comes from innovation, not adaptation.-Dhw: [...] every single innovation from bacteria onwards must in some way have proceeded from the drive to improvement, as opposed to the need for adaptation. The latter is a response to challenges from the environment, whereas improvement is a response to opportunities offered by the environment.-DAVID: This is the same response that you made above. It doesn't explain broad evidence of stasis, such as 250 million years of unchanged trilobites or 70 million year-old unchanged coelacanths. To me this is a strong sign of planned advances, such as 22 million years of monkeys to humans and the monkeys still exist unchanged. Why a complexity push only here and there?-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. Once again, innovation is the phenomenon that requires explanation: i.e. individual organisms finding the ability to do something new in a given environment, as a result of which their own physical structure changes. Earlier I suggested the emergence of dry land as an example: some aquatic creatures will stay in the water, but others will explore the new environment, and their cell communities will cooperate to restructure themselves. Similarly, most monkeys may have stayed in the trees, but at some point others (perhaps through a change in their own local conditions) may have decided to come down and explore the plains. “May have”, because nobody knows. Why a complexity push only here and there? Because all innovations must take place in individual organisms, and just as individual humans come up with new ideas “here and there”, so did other organisms throughout the history of evolution.
 
DAVID: Please see my entry on Koonin.
dhw: The basis of it all is endosymbiosis. Lynn Margulis was a pioneer in this field, and she believed in the intelligent cell.
DAVID: And I believe in intelligent information running the cells. I will stick 100% to my side of the 50/50.-And I will stick to the infinitely more logical division of 50% to 50%.