The Intelligent Cell (Origins)

by dhw, Saturday, December 17, 2011, 15:24 (4723 days ago) @ David Turell

DAVID: Lets climb up into the trees 6 million years ago. We are two common ancestors looking at a growing savannah. One of us stays roughly the same and the other becomes US, the H. sapiens. Why did we climb down? What drove us? Nothing we know of. We cannot relive ancient history. We can only guess. But one of us did get down. That guy lost those heavy arm and shoulder muscles and as part of the changes grew a giant brain.
The savannah gave both of us the option to try a different lifestyle, but it did not require it. Natural selection requires some sort of challenge. The climate change doesn't seem to offer any. As a result, we really have no idea why this happened. But it did, and we are here, in all our glory.

I’m not thinking of two common ancestors looking at the same savannah, with one changing and the other staying the same. I’m thinking of one particular area where the forest disappears. ALL our guys and dolls have to get used to savannah life, whereas elsewhere life can continue the same arboreal way. We know it takes two to tango, but with this scenario you have a whole tribe to tango. If epigenetics and Lamarckism can stand up to it, you have all the “ancestors” in this one area needing to develop new skills, from which evolve the anatomical and intellectual changes that ultimately lead to us.

DAVID: If an open option allows an advantage in complexity, but does not require it, why did it happen? Dumb luck or some push to complexity? I think there is a pushing mechanism and that it will be found in the near future. To be nice, I think your theory is possible, but not reasonable without some pushing somewhere.

The push would be environmental, with change required by natural deforestation. 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!