More about how evolution works; stasis (Evolution)

by dhw, Sunday, October 18, 2015, 12:39 (3322 days ago) @ David Turell

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.-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.-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?
 
dhw: Once again, innovation is the phenomenon that requires explanation.-DAVID: Under our current state of knowledge innovation is not explained. -Yep, that's why we come up with our different theories.-DAVID: It is probable that changes of environment cause adaptations. This is well known as epigenetic alterations. We do not know if it leads to speciation, which is what you are trying to imply. And it is just as possible that innovation is produced by God's plan.-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). However, I'm glad you now regard this as being just as possible as your divine 3.8 billion-year computer programme or divine dabbling (= God's planning, as opposed to individuals seeking improvement). At least you have progressed to 50/50. -dhw: 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. [...]-DAVID: There are no good transitional forms from fish to land animals. Just 'sort of' specimens. And in most of the fossil records new species appear with no predecessor of small intermediate changes. The jumps are huge. Your theory is son-of-Darwin and requires the itty-bitty changes which don't exist. You can live with the hope for a better supporting fossil record, as did Darwin, but 150 years later, no luck.-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. A fish that slithers onto dry land will die if it can't breathe or move.