44th human-orangutan synapomorphy

John Grehan jgrehan at SCIENCEBUFF.ORG
Fri Jan 14 09:12:00 CST 2005

Richard's suggestion that the mechanical ability is something ancestral
to primates and lost in all groups except orangutans and humans is a
reasonable possibility. It would seem to imply that there have been
multiple losses of the ability within primates. But on the other hand it
could be that the ability evolved in different lineages and the
orangutan-human ability represents a novel development within the
primates. I am distinguishing mechanical ability from problem solving in
general although the former could be seen as a subset of the latter
(then again I'm not a behavioralist and perhaps a specialist would
disagree with that separation). I don't think I'm getting carried away,
although one never knows. For now it seems that there is a substantial
difference in the mechanical ability and inclinations of humans and
orangutans compared with all other primates so that stands as a
character that brings them together. On the face of it, the ability is a
uniquely shared character within the primates. It is that context upon
which I would look at it as a synapomorphy.

John Grehan

> -----Original Message-----
> From: Richard Jensen [mailto:rjensen at saintmarys.edu]
> Sent: Friday, January 14, 2005 4:17 AM
> To: John Grehan
> Subject: Re: 44th human-orangutan synapomorphy
> I suggest that mechanical ability is a plesiomorphy, having arisen
> earlier in the animal kingdom.  Certain canids and felids illustrate
> problem-solving ability and felids in particular are quite adept at
> manipulating objects (e.g., opening cupboards, sliding latches, and
> similar tasks).  Octopi are also well-known for their ability to solve
> problems, e.g., figuring out how to unscrew lids from closed jars.
> Let's not get carried away on what constitutes a synapomorphy -
perhaps a
> retained plesiomorphy or homoplasy is the
> correct interpretation.
> Cheers,
> Dick
> John Grehan wrote:
> > Well, thanks to Ken helping me to look more closely at the situation
> seem to have another confirmed orangutan-human synapomorphy. I decided
> check with a specialist on primate cognitive behavior regarding the
> mechanical inclinations of orangutans (and their assoicated abiity to
> escape by unlocking cages) and my impression from the literature was
> corroborated. This person told me that "orangutans are mechanical
> geniuses.  This has long been recognized, and I don't know of anything
> that contradicts this impression of the 'bent' of their intellect." So
> seems safe to include mechanical ability as the 44th  synapmorphy with
> humans even though there is no numerical quantification. It would seem
> that humans and orangutans are noteable for mechanical ability and
> that other primates just don't show up on the radar screen. Perhaps
> key to the 'success' of human evolution lies with having a common
> with the orangutan - a common ancestor that thought far more like us
> > than chimps.
> >
> > John Grehan
> >
> --
> Richard J. Jensen              | tel: 574-284-4674
> Department of Biology      | fax: 574-284-4716
> Saint Mary's College         | e-mail: rjensen at saintmarys.edu
> Notre Dame, IN 46556    | http://www.saintmarys.edu/~rjensen

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