Evolutionary forces

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Evolutionary forces
Selection Mutation Migration Genetic drift In
the absence of these evolutionary forces, what
happens to allele frequencies from one generation
to the next, assuming that mating is random?
And now for a brief reminder, using Jon Herrons
AlleleA1 program ...
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Linanthus parryaeDesert Snow
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What evolutionary force might produce the
observed distribution of flower color?
What sort of experiments or observations are
needed?
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Sewall Wright1889-1988
And now for a brief reminder, using Jon Herrons
AlleleA1 program ...
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11 years, 41,718 plants, and 713,364 seeds later
...
Doug Schemske and Paulette Bierzychudek(2001)
Evolution 55 1269-1282.
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Major conclusions

• Flower color polymorphism was not established,
  and is not maintained, by random genetic drift
• Selection is strong
• Polymorphism is maintained by temporal variation
  in the direction of selection