Re: What did AAT Supposedly eat?

Rod Hagen (rodhagen@insane.apana.org.au)
Mon, 23 Jan 1995 10:10:56 +1000

In article <3epjv1$ict@newsbf02.news.aol.com>, patdooley@aol.com (Pat
Dooley) wrote:

>
> Primates have been arboreal for tens of millions of years. Most primate
> species are still well adapted for such an environment. In those time
> scales, evolution works out most of the flaws. Lucy was clearly descended
> from an arboreal ape ancestor but her unique features certainly didn't
> come from the common ancestor of humans and bonobos.

Always wondered how the AAT people think the arboreal apes got a taste for
the water in the first place. Dropping from the trees into the water
perhaps? And how did they get out again? Mangroves? Isn't a primarily
terrestrial phase at least probable? If so, I can think of some good
reasons for standing on two legs other than for keeping your nose out of
the water. Firstly, it lets you reach higher for tucker, without having to
go to the trouble of climbing a tree, getting down again etc. This
revalation came to me while picking fruit on some trees that had grown too
high. Its far more efficient (i.e. more fruit in less time) to just walk
along reaching the ones that you can, than it is going up and down (aided
with a ladder to compensate for my non-arboreality) to get the stuff. A
height advantage (confered by bidepality) is a definite plus in this
regard.

The revelation was enhanced by watching our airedale terrier trying to get
to some of the plums. She stands momentarily on her back legs trying to
reach the higher ones, but she is not as good at it as me, so she gets
less plums! (Our border collie has a different strategy, she jumps. This
looks very inefficient in energy terms. It also looks very funny when she
lands on her back with a squishy plum squashed all over her face and her
tail wagging).
>
> Somewhere between 12 mya and 4 mya, human evolution proceeded
> down a different path from that followed by other ape species.
> It wasn't the big brain, because Lucy had the usual ape sized brain.
> It wasn't tools, because Lucy wasn't up to using them, at least any
> more than present day apes use tools. It can't have been continued
> arborealism because bipedalism is an innapropriate adaptation.
> The direct descent to the savannah theory has a multitude of problems,
> not the least of which is explaining how it could have evolved without
> disadvantageous intermediates.

But a direct descent to the water theory still needs to explain the
initial splash!

>
> So, there are no bipedal aquatic mammals. But no primate species
> have ever made such a transition, except, perhaps, one. As has
> been repeatedly pointed out, when you lead a primate to water,
> it wades in on its hind legs.

When you lead an airdale terrier to a plum tree it stands on its hind legs
too (could this be the start of the prunus canine theory!)

;-)

Rod

-- 
Rod Hagen
rodhagen@insanity.apana.org.au
Rod_Hagen@maccontent.apana.org.au