The Intelligent Cell (Origins)

by dhw, Sunday, December 18, 2011, 11:34 (4722 days ago) @ David Turell

I suggested that a “tribe” of our common ancestors may have been forced by natural deforestation in a particular region to adapt to savannah life, thereby having to develop new skills with all the concomitant anatomical and mental changes.

DAVID: This opinion comes from Stephan, Niles, David H.. It is the punctuated isolation equilibrium theory that fits the huge jumps in Darwinism that don't fit the bearded one's proposal. All the guys have to do is follow the receding forest margins, and not bother to change. Animals usually follow the path of least resistance.

I’m delighted to hear that I’m in the company of professionals, though I really didn’t imagine I was the first to hit on the idea! We needn’t dwell on Darwin’s gradualism. I’ve already said many times that (a) I don’t accept it, and (b) I don’t understand why he thought it was so crucial to his theory. It isn’t. Your objection to what I now know is called punctuated isolation equilibrium theory (I’m impressed!) assumes that our ancestors were in a position to follow the receding forests. Isolation can have many causes: mountains, lakes, seas, deserts; or there may be fierce competition as the habitat shrinks (assuming it isn’t wiped out suddenly), again requiring a change of lifestyle. What animals “usually” do doesn’t preclude exceptional circumstances producing exceptional consequences. No-one has explained how humans evolved, but we do know that isolated areas have produced unique species (think of Madagascar), so the isolation scenario has its precedents.

DAVID: To be nice, I think your theory is possible, but not reasonable without some pushing somewhere.

Dhw: The push would be environmental. […] Africa is a vast continent – there is no reason why such an event should not be localized to a single region. It would only need one to start the process. Now perhaps you can be even nicer!

DAVID: I can be a little naughty at times, but generally I am very nice. You haven't disproved the need for genome guiding pushes!

And you haven’t disproved the theory that environmental pressure may have provided the push. No-one has yet proved or disproved anything. But you and I have always been nice to each other, and when we are naughty, it’s fun! You are angling for “genome guiding pushes” because, I presume, they would fit in with your concept of pre-planning. I’m angling for environmental change as the trigger and epigenetics as the mechanism, not to pursue any agenda but because it seems to me to fit in better with the long history of evolutionary comings and goings. This doesn’t run counter to design theory (or to chance theory, but that’s another matter) – only to your view of its scale and implementation. Do you really believe that every single environmental change and every single species extinction was planned by God as an essential step to the creation of humans?