CAS BI 107 Lecture Notes - Lecture 7: Brown Anole, Population Bottleneck, Cummington, Massachusetts
4 Nov 2016
School
Department
Course
Professor
Document Summary
Office hours: 5 cummington street room 423 mwf 4-5pm: gene flow. When organisms are located close to one another, there will be gene flow between the two sets of organisms. This causes homogeneity and will decrease the isolation of populations (decrease chance of speciation, but more on that later: genetic drift. Example: the amish who carried a particular set of genes genetic drift isolates rarer genes that could cause both positive or negative effects. Founder effect: immigration of a set of individuals to establish a new population: is how we believed speciation occurred. Genetic bottleneck: high mortality striking individuals at random. Both founder effect and genetic bottleneck result in a different genetic makeup of the population, which breaks hardy-weinberg equilibrium! Examples of the bottleneck effect: take a large population and randomly reducing the number of individuals randomly, leads to homozygosity and decrease in heterozygosity, example: flowers. Allele frequencies p(frequency of r): 14/20 = 0. 7 q(frequency of r): 6/20=0. 3.
