Bite makes way for brain A single mutation may have caused
gross anatomical changes that spurred human evolution By
Brendan A Maher March 24, 2004
A pile of evidence from disparate disciplines indicates that
a single change in a single gene-MYH16-may be responsible
for significant morphologic differences between humans and
other primates, including possibly the three-fold increase
in brain size that set the earliest species of [censored] apart
from their kin. This is the first protein disparity between
humans and chimps that can be correlated to drastic
anatomical changes seen in the fossil record, according to a
group of University of Pennsylvania researchers who
published a letter in the March 25 issue of Nature.
"This is a brilliant piece of detective work that has
enormous implications for medicine, biology, evolution,
molecular genetics, [and] the human genome," said Frederick
S. Kaplan, a professor of orthopedic molecular medicine at
Penn who was not part of the study. "By relegating a gene to
the evolutionary garbage heap, we were able to lift the
constraints to the development of human complexity," he told
The Scientist.
Powerful muscles for biting practically dominate the cranial
structures of most primates, including gorillas, chimps, and
extinct Australopithecus and Paranthropus species. A gene
responsible for a majority of jaw musculature was lost from
human ancestors, presumably 2.4 million years ago, according
to the study. Drastic reductions in these muscles may have
lifted significant physical constraints on braincase volume,
allowing primates with weak jaws and big brains to
eventually think about their origins.
Read the rest at The Scientist dot com
biomedcentral.com04Open ↗
Posted by Robert Karl Stonjek.