Population Genetics

23.1 populations genetics provides a foundation for studying evolution - today we can define evolutionary change on its smallest scale, or microevolution as a change in the genetic makeup of a population from generation to generation. - darwin found a mechanism for change in species but he did not get good results on how the heritable variations required for natural selection.  natural selection  fitness - contribution an individual makes to the gene pool of the next generation   3 types of selection  A. directional  B. diversifying  C. stabilizing .  gene pools and allele frequencies:  Darwin considered raw material for natural selection to be "quantitative"  population genetics are  the study of how populations change genetically over time population a localized group of individuals that are capable of interbreeding and producing fertile offspring  - populations from of the same species may be isolated from one another although genetic material can only rarely  -individuals near the same population are more likely to breed with members of there own populations  the aggregate of genes in a population at any one time is called gene pool HARDY WEUNBERG THEROM:: shows that the frequencies of alleles and genotypes in a populations gene pool remain constant from generation to generation , provided that only mendelian segregation and recombination of alleles are at work  23.2 mutation and sexual recombination produce the variation that makes evolution possible  mutations are changes in the nucleotides sequences of DNA  a mutation is like a shot in the dark  sexual recombination : is more important than mutations !!