BIO120H1 Lecture Notes - Lecture 5: Selective Breeding, Neo-Darwinism, Balancing Selection

• School: UTSG
• Department: Biology
• Course: BIO120H1

Document Summary

1930-1950 theoretical population genetics was initiated by. Fisher, haldane, and wright and provided the foundations for. Showed that continuous variation and darwinian natural sleection were entirely consistent with mendel"s laws. Demonstrated the evolutionary significance of genetic variation leading to severl key questions and development of the field of ecological and evolutionary biology. Imporant parameters used to measure patterns of genetic variation: fractions of genes sampled in a population that have more. Polymorphism (p) than one type of allele. Heretozygosity (h: average frequency of heterozygous individuals per gene. Locus = site on chromosome that is usually a gene locus. Processes influence patterns of genetic diversity: ultimate source of genetic variation, caused by random errors during replication, the shuffling of genetic variability, random sampling effects every generation. Natural selection (increase or decrease: important when populations become small. Lose alleles by chance: reduces genetic variability, purifying sleection, positive selection. Mutations that increase fitness become fixed: balancing selection.