Article: How Did Natural Selection Shape Human Genes?

Aggression was certainly not a neutral mutation. I don't
think we would have ever evolved to where we are without
some very important mutations being the result of Darwinian
selection. The problem, however, is some of those mutations
due to natural selection are no longer adaptable for us as a
species. I recently told a colleague I defined intelligence
as adaptability. This is not the conventional definition of
intelligence. I told him we were not adaptable as a species
anymore. He replied, "But humans are very adaptable." I
replied, "Yes, but we are destroying the planet and each
other. His response was there are different kinds of
adaptability. In some respects we are highly adaptable and
in others not at all. The question is do our "non" adaptive
adaptations (such as aggression) cancel out our incredible
adaptability in other areas? The jury is out on that but I
think without genetic engineering (which will happen whether
we like it or not) the answer is yes...meaning we destroy
ourselves before genetic engineering advances to the point
it can modify our aggression. So I define intelligence as
survivability and ultimately adaptability.

Michael Ragland

How Did Natural Selection Shape Human Genes?

Group: sci.bio.evolution Date: Mon, May 10, 2004, 2:49am
(EDT+4) From: [email hidden] (Robert Karl Stonjek)
How Did Natural Selection Shape Human Genes?

A paper proposes that climate favored certain mitochondrial
DNA polymorphisms By Douglas Steinberg

Many selective forces must have influenced human evolution,
but the only one that all population geneticists seem to
agree upon is malaria. Time and again, studies have
identified certain DNA polymorphisms--most famously, the ß-
globin variant underlying red-cell sickling--that helped
people resist this mosquito- borne disease. The reproductive
success of such individuals spread these polymorphisms
throughout regions where malaria is endemic. Geneticists
have been much more reluctant, in contrast, to conclude that
other selective forces favored or dis-favored particular
polymorphisms. That attitude is changing, however, as
technological advances allow the rapid sequencing and
analysis of genomes. Researchers are increasingly seeking
evidence of natural selection, as they question whether many
newfound variants are as "neutral" as a theory dominant
during the past 20 years would suppose. Promoted by the late
Motoo Kimura, the neutral theory of molecular evolution
holds that most polymorphisms confer no fitness advantage or
disadvantage, and spread or disappear randomly. "The problem
is that we've now saturated the neutralist hypothesis,"
contends Douglas C. Wallace, a professor of molecular
medicine at the University of California, Irvine. "There are
more things going on than that, and we have to go back to
Darwinian selection." In a new paper, Wallace and colleagues
at UC-Irvine attribute some polymorphisms in human
mitochondrial DNA (mtDNA) to climatic adaptation. Other
recent research suggests how selective forces might have
affected autosomal genes2 and casts doubt on the neutrality
of Y-chromosome variation. Besides illuminating evolution,
these studies have a potential clinical benefit: Knowledge
of DNA variants' evolutionary fitness might provide clues to
developing better gene-based diagnostics and therapies. Read
the rest at The Scientist.com the-the-Open ↗
scientist.com/yr2004/may/research2_040510.html Posted by
Robert Karl Stonjek.