Note on hominid genetics and morphology

[John Grehan]

For those interested, the following text is from a letter published
earlier this month in the Letters to the Editor column of the Dominion
Post newspaper in New Zealand. I've already noted for the second
paragraph that instead of "support a common ancestor" I should have said
"support a most recent common ancestor".

 

Conflict with the Evidence

 

Bob Brockie's recent reference to the Flores fossils (Dominion/Post 8
November, 2004) as dwarfed descendant of Homo erectus overlooks concerns
expressed by several paleontologists such as David Begun, Colin Groves,
Jeffrey Schwartz, and Milford Wolpoff, that some features, such as the
roots of the teeth, are more like the African Australopithecus or very
early Homo rather than the relatively recent Homo erectus. 

 

Brockie suggested that DNA extraction might solve the question of the
hobbit's identity, but this would not allow comparison with fossilized
remains and DNA sequences sometimes conflict with morphological evidence
and may, therefore be misleading. The classic example is the 98%
similarity of DNA sequences between humans and chimpanzees and yet we
share almost nothing uniquely in common with chimpanzees that would
support a common ancestor.

 

In contrast to DNA similarities, humans and orangutans share at least 40
unique features, such as thick dental enamel, low molars, and lack of
genital swelling, which would support a most recent common ancestor
excluding the chimpanzee. Rather than relying on DNA sequences that
don't always match evolutionary relationships, the critical issue will
be open access to the fossils by other researchers. At present this
access appears to be in doubt.

 

 

Dr. John R. Grehan

Director of Science and Collections

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/biogeography_and_evolutionary_biology.php

Ghost moth research

http://www.sciencebuff.org/systematics_and_evolution_of_hepialdiae.php

Human evolution and the great apes

http://www.sciencebuff.org/human_origin_and_the_great_apes.php