Dominant/Recessive Genes

Toby Bradshaw toby at
Sun Feb 27 12:09:35 EST 1994

In article <genecutl-260294184506 at>,
gc <genecutl at> wrote:
>The question about maintaining genetic diversity is meaningless.  A
>species does not decide to maintian genetic diversity.  Genetic diversity
>or not is effected by selection on specific phenotypes.  Given a closed
>population with a low mutation rate, a loss of genetic diversity would
>be inevitable.  

Depending on interactions among alleles, a closed population will not
necessarily lose genetic diversity.  Consider the (unlikely) case that
all allelic interactions are overdominant, and that all new mutations
contribute to overdominance.  Selection favors heterozygotes at every
locus, and in populations large enough for drift to be an insignificant
force in evolution allelic diversity is maintained.  I think "inevitable"
is therefore too strong a term to apply above :)

Toby Bradshaw                       |
Department of Biochemistry          |  Will make genetic linkage maps
and College of Forest Resources     |            for food.
University of Washington, Seattle   |
toby at               |

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