BIO 115 Lecture Notes - Lecture 18: Allele Frequency, Pleiotropy, Genetic Drift
Document Summary
Genetic drift results from random sampling error. Sampling error is higher with smaller samples. Random changes in allele frequencies across generations. There is much more variability in smaller populations drift recudes the genetic variation in a population. Alleles are lost or fixed at a faster rate in small popualtions. The larger the population, the more likely you"ll see the hw predictions. Random, non-representative sampling of alleles from a population during breeding. Once this event happens, new alleles are only introduced through migration or. Rare alleles are more likely to be lost. Green: allele frequency is very low=very rare. Probability of losing the population is very high for the green line mutation. Does dip down a little as the population size increases. Even brief bottlenecks can lead to a drastic reduction in diversity that lasts for generations. Small group of an interbreeding population that splits off and starts its own. Ex: high incidence of migraine headaches attributed to founder effects.
