Synthesis Notes

Ne is more towards the historical size rather than

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: variation…? What effects does it have on genes in terms of prob. of fixation, change in variation, change in heterozygosity? • When there are few copies of an allele, the effect of genetic drift is larger, and when there are many copies the effect is smaller. • removing genetic variation from populations  ­ decreasing the heterozygousity • Probability of fixation for any new neutral mutation: 1/2N • On average, how many neutral mutations in each generation will fix: μ • Rate of neutral evolution is independent of population size. Assuming mutation rate does not change, the rate of neutral evolution should be constant. Foundation of the Neutral Theory of Molecular Evolution What are bottlenecks and founder effects? • Bottleneck ­ A temporary decrease in population size due to something such as an environmental change. o tend to reduce variation and make drift occur stronger and faster o heterozygosity decreases o strong when they stick around for a few generations • Founder effect ­ the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. o an example of bottleneck effect o Book—a change in allele frequencies that results from sampling effects that occur when a small number of individuals derived from a large population initially colonize a new area and found a new population What is an effective population size? • The size of a Wright ­Fisher population that w...
View Full Document

This note was uploaded on 05/18/2013 for the course BIOL 3040 taught by Professor Staff during the Spring '08 term at LSU.

Ask a homework question - tutors are online