Transcript Population Genetics

Population Genetics
Marie Černá
Population
a localized group of individuals
belonging to the same species
a species
a group of populations whose individuals
have the potential to interbreed and
produce fertile offspring in nature
Population genetics
(in the 1930s)
• Study of the properties of genes within
populations (gene pool)
• The genetic structure of a population is
defined by its allele and genotype
frequencies
• Microevolution
is a generation-to-generation change in a
population’s allele or genotype frequencies
Modern synthesis
(forged in the 1940s)
• a comprehensive theory of
evolution
• integrates Darwinian selection
and Mendelian inheritance
Hardy-Weinberg equilibrium
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very large population
no migration
no net mutations
random mating
no natural selection
in a population meeting all these conditions
- no evolution is occurring
Hardy-Weinberg equilibrium
p = frequency of dominant allele
q = frequency of recessive allele
allele frequencies: p + q = 1
genotype frequencies:
(p + q)2 = p2 + 2pq + q2 = 1
Literature
Biology, eighth edition,
Campbell, Reece
Unit four: Mechanisms of Evolution
Chapter 23: The Evolution of Populations
Pages 468 – 486