B
buffalo
Guest
No one argues change, we argue the leap of faith that it will take you all the way from molecules to man.Yes. But they changed over time and the changes were driven by natural selection. The change was cyclical because the environment (the weather in that case) was also cyclical. Natural selection drove changes to follow the changing environment. The environment changed cyclically, so natural selection drove change cyclically.
Merely because it was cyclical does not mean it was not change. The cyclical part is not relevant. Natural selection was not conservative in that case, it drove change. Your earlier statement is not correct for all cases. Only in a static environment is natural selection uniformly conservative.
Natural selection drove the change from pale to dark. Then when the air became less polluted it drove the reverse change from dark to pale. Natural selection in a changing environment is not a conservative force, it is a force for change. This has been shown by many examples. The deep sea is a relatively unchanging environment, and there change does indeed move very slowly.
Natural selection is not intrinsically conservative; it reflects the environment. Conservative in a static environment, a driver of change in a non-static environment.
rossum
Natural selection is conservative in allowing limited variation to accommodate changing environments. It is not creative, it preserves the organism.