This is where I have a problem.
In both of these treatments evolution is viewed like it is goal oriented.
Initial and final values of a trait over some mm years
How long to double the size of a mouse
Whatever numbers, in darwins or in haldanes, one achieves are arbitrary and meaningless.
It took X million years for this
A. whosits to grow a widget from # cm ## cm.
And it took Y million years for the
B. thingies to double the size its whatever.
A. whosits took 62 darwins from this phenotype to that.
B. thingies took 65 darwins from this phenotype to that.
Does this mean *evolution* was faster for the whosits than the thingies and does it really matter?
All it means is that more time elapsed from this arbitrarily chosen version of the whosits to that one, than it did for the two arbitrarily chosen versions of the thingies.
Neither of these gives a rate to evolution but just a length of time to go from this version to that version. And this is not just semantics since it was not evolution that changed but the inputs to its processes that changed.
We also know from some experiments that high stress can lead to more mutations as the immune system is suppressed and control systems over cell structure weakens.
This changes the inputs to the processes but does not change or speed up those processes. Stress Response Mutations only give the processes more to work with initially than they would without that scheme. They add to the available allele pool they do not make the selection or distribution of alleles any faster.
My view. Evolution ran, not at any rate, but just ran day by day, generation by generation, for both lineages, but one took longer than the other for some various reasons dealing with chemistry, allele pool, environment, fecundity, luck, and circumstance.
Evolution does not speed up or slow down in comparison between sets of phenotypes. Each phenotype takes however long it takes generation to generation and comparisons between phenotypes are useless since each evolves by its own unique circumstance.
Is this just semantics on my part? Is the "evolution" of the fruit fly "faster" than that of the elephant? Or does evolution just plod along dependant on the inputs?
Edited by AZPaul3, : No reason given.
Eschew obfuscation. Habituate elucidation.