What we know…

Genetic Variation causes evolution What we know… Genetic Variation causes evolution

Genetic Variation can be measured by Average Heterozygousy What we know… Genetic Variation can be measured by Average Heterozygousy

Genetic Variation does not guarantee that evolution to occur But… Genetic Variation does not guarantee that evolution to occur

If a population is not evolving, it is in Hardy-Weinberg Equilibrium

Conditions of Hardy-Weinberg Equilibrium No mutations – no new alleles Random Mating – no preferences in mating will allow all traits to be passed on No natural selection – all traits are equally beneficial Extremely large population size No gene flow Gene flow: movement of alleles in and out of a population due to the movement of fertile individuals or their gametes Example: ability of human population to travel large distances

If all of these conditions are met, then a population WILL NOT evolve.

Hardy-Weinberg Principle:

Hardy-Weinberg Principle: frequencies of alleles and genotypes in a population will remain constant from generation to generation

Testing a Population for Evolution Calculate expected genotypic frequencies and compare to actual genotypic frequencies ….in english….what percent of the population should have a certain genotype compared to what percent ACTUALLY has that genotype If the expected matches the actual, no evolution is occurring If expected does not match the actual, evolution could be occurring

Equation for Hardy-Weinberg Equilibrium p2 + 2pq + q2 = 1 Two alleles possible for a trait (G and g) p = frequency of dominant allele q = frequency of recessive allele p2 = expected frequency of GG pq = expected frequency of Gg q2 = expected frequency of gg p + q = 1

Equation for Hardy-Weinberg Equilibrium p2 + 2pq + q2 = 1 We get these frequencies from Punnett Squares Use the decimal form of the %