Chapter 14
Microevolution in Modern Human Populations
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Human Populations
Population Genetics
Evolution in Action: Modern Human
Populations
Human Polymorphisms
Human Bicultural Evolution
Population Genetics
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Once a population is identified, can determine
if evolutionary forces are operating on the
population.
Measure allele frequencies for specific traits
and compare them with the Hardy-Weinberg
model.
Hardy-Weinberg Equilibrium
Evolution is not taking place if:
1. Population is infinitely large.
2. No mutation.
3. No gene flow.
4. Natural selection is not operating.
5. Mating is random.
Factors that Initiate Changes in
Allele Frequencies
1.
2.
3.
4.
Produce new variation (mutation).
Redistribute variation through gene flow.
Redistribute variation through genetic drift.
Select "advantageous" allele combinations that
promote reproductive success (natural
selection).
Human Biocultural Evolution
Polymorphisms
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ABO Blood Group system
Rh system
MN blood group
Human Biocultural Evolution
Examples of the interaction of human
cultural environments and biology:
 Sickle cell disease
 Lactose intolerance