Great Apes again (was: Red Ape book...)

John Grehan jgrehan at SCIENCEBUFF.ORG
Fri Jan 7 23:47:57 CST 2005


From: Taxacom Discussion List on behalf of Ken Kinman
Sent: Fri 1/7/2005 6:27 PM
Subject: Re: [TAXACOM] Great Apes again (was: Red Ape book...)

     You would disregard Shoshani et al.'s character 163 just because it is also found in a distant outgroup like Tarsius (and Pteropus is even more distant).  That might be a reason to give it LOWER weight, but not ZERO weight.  


And the Gorilla-Pan-hominid synapomorphies definitely are pertinent because they would help confirm a Pan-hominid clade and help disprove an orangutan-hominid clade.  But I can see how that kind of double-whammy would make you very uncomfortable.

Since the characters for all three make no distinctions for any two I can't see how they can 'confirm' such. At best they would do is support a human-African ape clade as opposed to an orangutan-humid clade.

      You seem very harsh towards anything that leans toward a chimp-hominid clade, and relatively uncritical of your own choice of characters for an orangutan-hominid clade.  

I guess its a matter of perspective as to whether one is as critical of one's own characters as those of others. I'll leave that for others to judge as they wish. However, I am not as 'harsh' as most primate systematists who will not even discuss the proposed orangutan characters or respond to critiques of their own characters.

Why not combine "Adult & Juvenile incisive foramen condition", instead of splitting it in two.  You call that two independent characters?  

They each occur at different developmental stages so that's the choice that was made. I would not object to others making their own choice. 

Same for "Estriol levels high during menstrual cycle and pregnancy".  They seem connected as well.  

Since its the same organisms one would expect a connection of some kind, but the point here is that each is a specific physiological condition so they are treated as distinct characters.

So you are giving these DOUBLE weight, and yet you would give Shoshani's character 163 no weight at all???

Only double if its a repeat, but there is no evidence as far as I know to support what you have raised as a possiblity

      On the other hand you combine hair length into a single character.  If you split it into a body hair character and a head hair character, they wouldn't favor an orangutan-hominid clade at all.  Your character choices and how you weight them just don't make sense to me much of the time.  I still think you are stuffing the ballot box in your favor, whether you realize it or not.

Perhaps, but the fact remains that orangutans and humans have the longest hair of any primate. Once could chose to disregard that because the hair is on different parts of the body. Perhaps everyone (including DNA people) 'stuffs' the ballot box in some way, but at least it is evident here as to how the characters are being portrayed. In a lot of primate studies one cannot be so sure as the characters are not documented in any way (quite a few of Shoshani et al's are like that. Even the authors could not give me specific information on one of the characters when I asked). 

     ---Ken Kinman

P.S.  I am very surprised that Schwartz would reject Shoshani et al.'s characters 102 and 104 because the size of Gorilla might cause a scaling problem.  Even if it were a scaling problem, that would throw Gorilla in with the same coding as gibbons and orangutans, thus adding yet another two potential synapomorphies for a Pan-hominid clade.  You lose either way----unless you just throw them out and give them zero weight.  If you are going to be supercritical and throw out babies with the bathwater, then at least be fair and do the same thing to your orangutan-hominid list of characters.

Actually Schwartz did just that with gestation length by adjusting for body weight. Perhaps 102 and 104 might still favor chimps and humans, but the point is that these characters have been invoked by Shoshani et al without descriptive documentation necessary to give justification for theic choice and they have done it only for humans and African apes. If they re-evaluate the character as you suggest then certainly the picture might change.

Perhaps the 'fairest' choice would be to accept both sets of charactrers (chimp-human, orangutan-human) and see what happens with a combined data set. 

Thanks for the critical comments Ken. You are setting a standard for what the primate systematists should be doing.

John Grehan

More information about the Taxacom mailing list