[Taxacom] biased gene conversion

John Grehan jgrehan at sciencebuff.org
Wed Feb 11 11:04:04 CST 2009

Those on this list interested in evolutionary mechanisms may like to
comment on the piece below. I have not yet seen the original article. I
found their claims interesting because panbiogeography is the only
evolutionary framework (as far as I know) that has given explicit
credence to a major role for processes such as biased gene conversion.


John Grehan


Natural Selection Not The Only Process That Drives Evolution?

ScienceDaily (Jan. 28, 2009) - Why have some of our genes evolved
rapidly? It is widely believed that Darwinian natural selection is
responsible, but research led by a group at Uppsala University, suggests
that a separate neutral (nonadaptive) process has made a significant
contribution to human evolution.


Their results have been published January 27 in the journal PLoS

The researchers identified fast evolving human genes by comparing our
genome with those of other primates. However, surprisingly, the patterns
of molecular evolution in many of the genes they found did not contain
signals of natural selection. Instead, their evidence suggests that a
separate process known as BGC (biased gene conversion) has speeded up
the rate of evolution in certain genes. This process increases the rate
at which certain mutations spread through a population, regardless of
whether they are beneficial or harmful.

"The research not only increases our understanding of human evolution,
but also suggests that many techniques used by evolutionary biologists
to detect selection may be flawed," says Matthew Webster of the
Department of Medical Biochemistry and Microbiology at Uppsala

BGC is thought to be strongest in regions of high recombination, and can
cause harmful mutations can spread through populations. The results lead
to the provocative hypothesis that, rather than being the result of
Darwinian selection for new adaptations, many of the genetic changes
leading to human-specific characters may be the result of the fixation
of harmful mutations. This contrasts the traditional Darwinistic view
that they are the result of natural selection in favour of adaptive



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




Ghost moth research


Human evolution and the great apes




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