[extropy-chat] HISTORY: Solved & Unsolved Riddles

[kevinfreels at hotmail.com]

I am more inclined to believe that there were a variety of factors involved.
I think that when we start looking for causes of evolutionary change, we are
short changing it a bit. Suppose one A. Boisei survived to reproductive age
because they escaped from a predator because they spent more time standing
up because of a malformed joint at the base of the neck and were able to see
trouble coming before some others. Another A. Boisei stood up more often
because he had a slightly heavier head due to a larger brain than the others
due to some simple brain size variation and it simply felt better. These two
made children that stood up more often and had larger brains.
These children bred with a child formed from an A. Boisei that stood up more
because it kept his head cooler and one that stood up more often because her
arms were too short to knuckle walk effectively. One of their children is
born with shorter arms, more upright posture, and a bigger brain.
You could go on and on with this type of speculation and in the end, we may
simply never know.
----- Original Message -----
From: "Don Dartfield" <twodeel at jornada.org>
To: "ExI chat list" <extropy-chat at lists.extropy.org>
Sent: Wednesday, November 12, 2003 12:40 PM
Subject: Re: [extropy-chat] HISTORY: Solved & Unsolved Riddles


> On Wed, 12 Nov 2003, John K Clark wrote:
>
> > If you can see a predator better by standing up above the grass it also
> > means the predator can see you better, and that's bad news if you're
> > slow as molasses and if you walk on 2 legs you are. Better to just
> > briefly come up on 2 legs as many animals do and take a peek and then
> > come back down on 4, or just develop a long neck. I would think coming
> > out of the trees and into the open savannah would increase the trend
> > toward 4 leg locomotion, but that 's not what happened and I've yet to
> > hear a convincing theory that explained why.
>
> I read an evolutionary biology book that claimed we started standing erect
> mainly to help keep our expanding brains cool, via increased exposure to
> air currents and decreased sun exposure.  I'm not sure how well-researched
> and/or documented this claim was, though -- I was only 12 when I read the
> book, and I was a vehement creationist at the time, so I didn't really pay
> close attention to it or even read much of it at all.  Now I should go
> back to the library and try to find that book again...
>
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