Topic 13-1 Flashcards
the amount of variation within a population affects its potential to:
adapt to any environmental change
a branch of genetics that studies the genetic makeup of groups of individuals and how a group’s genetic composition changes over time (evolution)
population genetics
a group of interbreeding sexually reproducing individuals that have a common set of genes, the gene pool
mendelian population
in order to understand how genetic variation changes in a population over time, we first need to mathmatically describe:
the genetic structure of the population
the genetic structure of a population consists of:
1) types and frequencies of genotypes in the population
2) types and frequencies of alleles in a population
the sum all all genotypic frequncies always equals:
1 (or 100%)
how are genotypic frequncies calculated?
f(genotype) = (# of individuals w/ genotype) / N
N = population
different genotypes are just rearrangements of a set of alleles, so there are always:
less alleles than genotypes
allelic frequancies can be calculated from:
1) counting the number of alleles
2) the frequencies of genotypes
state the formula for allelic frequncy from numbers:
f(allele) = (number of copies of the allele) / (number of copies of all alleles at the locus)
a mathematical model evaluating the effect of reproduction on genotypic and allelic frequencies of a population
Hardy-Weinburg law
what are the assumptions of the Hardy-Weinburg law?
- population is large
- random mating within the population
- no mutations, migration, or natural selection
what are the predictions of the Hardy-Weinburg law?
1) allelic frequncies of a population do not change
2) genotypis frequencies stabilize (won’t change) after one generation –> f(AA) = p^2, f(Aa) = 2pq, f(aa) = q^2
when genotypes are in the expected proportions of p^2, 2pq, and q^2, the population is said to be in:
Hardy-Weinburg equlibrium
