[Taxacom] More on orangutan evidence

[John Grehan]

Invertebrate taxonomists at least will be familiar with the frequent use
of genitalia in species characterization as well as using these features
as phylogenetic evidence. One does not hear so much about their
application in primate phylogenetics although there has been some
descriptive work for some species. But  there may be something
phylogenetically informative about the male appendage within the large
bodied hominoids. 

 

Male chimpanzees and bonobos have minute spines along the shaft of the
penis. These features do not occur in humans, gorillas, or orangutans.
They do occur in the lesser apes (gibbons) and many Old World primates,
and perhaps many New World primates. The problem here is the lack of
comparison for all or even most monkeys. They are absent in lorisids,
but present in lemurs. 

 

Although the spines are absent in gorillas, they retain a polygonal
pattern of skin that each support a spine in gibbons and it has been
suggested in the literature that the gorilla shows a derived condition
in losing the spines that are retained in chimpanzees. Humans and
orangutans are uniquely similarity within the Hominoidea in lacking any
spines or associated dermal structures. The variable condition in
monkeys makes it difficult to determine if the human-orangutan condition
is truly derived, but it is another shared similarity that would make
sense in the context of a human-orangutan clade.

 

John Grehan

 

Dr. John R. Grehan

Director of Science

Buffalo Museum of Science1020 Humboldt Parkway

Buffalo, NY 14211-1193

email: jgrehan at sciencebuff.org

Phone: (716) 896-5200 ext 372

 

Panbiogeography

http://www.sciencebuff.org/research/current-research-activities/john-gre
han/evolutionary-biography
<http://www.sciencebuff.org/biogeography_and_evolutionary_biology.php> 

Ghost moth research

http://www.sciencebuff.org/research/current-research-activities/john-gre
han/ghost-moths
<http://www.sciencebuff.org/systematics_and_evolution_of_hepialdiae.php>


Human evolution and the great apes

http://www.sciencebuff.org/research/current-research-activities/john-gre
han/human-origins