Re: Bonobos and chimps
Stanley Friesen (email@example.com)
Fri, 22 Apr 1994 03:52:50 GMT
In article <camillaCoJB81.Jxv@netcom.com>,
Camilla Cracchiolo <firstname.lastname@example.org> wrote:
>I have a question: What I've read about the evolution of bonobos
>and chimps gives me the impression that primatologists and
>anthropologists think the bonobo line branched off the chimp
>line fairly recently. In other words, the common chimp came
>first, and then the bonobos.
Yep, that's about right. (Though some might want to call
the ancestral population cluster a distinct species from either
living chimpanzee - but that is a technical detail of little
real importance here).
> Yet everything I've read also
>refers to bonobos as being much closer morphologically to
>the proposed mutual ancestor of both humans and chimps than
>the common chimp.
This is, perhaps, a bit misleading. The bonobo is similar in
certain ecological adaptions and behavioral patterns to what
we believe the ancestral hominids were like. However, in most
features it is closer to the common chimpanzee than to early
hominids (like Australopithecus).
This sort of pattern is called convergent evolution, and often
occurs when two forms evolve under similar ecological conditions.
But, as in all such cases, the similarities are independently
derived, not retained ancestral traits.
>Why is this? I would think logically, and cladistically,
>it would be the other way around: that common chimps
>branched off the bonobo line.
On the other hand, this is not entirely clear. The date of
the *split* can be set to a fairly recent time, but in the
absence of fossils it is hard to say *which* species the
ancestral population would belong to.
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