bad science or good systematics?

John Grehan jgrehan at SCIENCEBUFF.ORG
Tue Jul 20 12:56:43 CDT 2004

For those on this list who think I am as thick as brick when it comes to
systematics I would be grateful for them to show me where I am missing
the obvious with respect to a paper titled "Sister grouping of
chimpanzees and humans as revealed by genome-wide phylogenetic analysis
of brain gene expression profiles". (PNAS 101 (9), 2004, page


Given the title of the paper I expected to see another genetic argument
supporting the sister group relationship of chimpanzees to humans. That
is what is claimed in the abstract where it is stated that "these
profiles demonstrate that chimpanzees are the sister group of humans".


What I did find was that the authors started with the accepted fact that
chimpanzees are the sister group to humans. They then went on to compare
brain expression profiles of humans, chimpanzees, gorillas, and
macaques. In the next to final sentence they conclude that their results
"depict, during descent of several catarrhine primates, gene expression
profile changes that group the chimpanzee clade closest to the human
rather than to the gorilla clade".


It seems to me that what is wrong with this paper is at least the title
and abstract. If there is any sister group relationship demonstrated
between humans and chimpanzees, it is only in the context of comparing
four selected taxa, with the notable absence of the orangutan. To me the
title and abstract are misleading at the least, and moreover possibly


And yet it got into PNAS as a high quality work. What did I miss?


John Grehan


John R. Grehan
Director of Science and Collections

Buffalo Museum of Science

1020 Humboldt Parkway

Buffalo, NY 14211-1193

email: jgrehan at

Phone: (716) 896-5200 ext 372


More information about the Taxacom mailing list