BIO152H5 Lecture Notes - Lecture 15: Standard Deviation, Allele Frequency, Genetic Drift
Document Summary
Lecture 15: evolution of populations: part b (ch 23) No tutorial on friday scientific literacy help sessions today: 11 am to 1 pm rgasc. Conditions for hardy-weinberg equilibrium the five conditions for nonevolving populations are rarely met in nature: random mating. Concept 23. 3: natural selection, genetic drift, and gene flow can alter allele. Frequencies in a population three major factors alter allele frequencies and bring about most evolutionary change: Differential success in reproduction results in certain alleles being passed to the next generation in greater proportions. Natural selection can cause adaptive evolution, an improvement in the match between organisms and their environment for example, an allele conferring resistance to ddt in fruit flies increased in frequency after ddt was used widely in agriculture. Genetic drift the smaller a sample, the greater the chance of random deviation from a predicted result. Genetic drift describes how allele frequencies fluctuate unpredictably from one generation to the next.
