More about how evolution works; stasis (Evolution)

by David Turell , Saturday, October 17, 2015, 22:23 (3323 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.-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.-> dhw: 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.-Under our current state of knowledge innovation is not explained. 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 tying to imply. And it is just as possible that innovation is produced by God's plan.-> 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. 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,...-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.