More on human-orangutan analysis

[John grehan]

At 02:56 PM 6/25/2003 -0500, Will Fischer wrote:

>3.  However, and finally, the analyses of soft tissue characters (both
>in 2000(+) and 2002(++)) got the same tree as the molecular data.

Unless I missed something it seems that this study is problematic for its
lack of outgroup comparison since the only taxa included were the great
apes (at least as far as I was able to determine and I have been unable to
obtain verification from an author I contacted) which would to me to be a
rather inadequate approach to the systematics of this group.

Given that I have found other purported human-chimp/African ape apomorphies
to also occur in monkeys I wonder how much this is also the case here. Many
of the characters are based on a scattered array of publications spanning
many decades between them so I am not sure to what extent they have
investigated the veracity of the characters used even without including
monkeys for outgroup verification. I am in the process of checking the
literature sources for the soft tissue analysis - a long process.

It is my current proposition that humans and chimps are most similar to
each other in terms of overall similarity and this applies to both gene
sequences and morphological characters (even though there may not always a
precise match). In terms of shared derived features the weight of evidence
in total proposed morphological synapomorphies is greater for the
human-orangutan relationship but unfortunately these characters are
generally excluded from the competing models.

John Grehan