notesBIO2 - (AA normal targeted by malaria, Aa carrier but...

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

View Full Document Right Arrow Icon
Hardy Weinberg Allele frequency: p + q =1 Genotype frequency: p2(homozygous dom) + 2pq(heterozygous) + q2(homozygous rec) = 1 Example: “A” eats all humans and “a” only Stevens. 1. Homozygous dominant plants is: .1 p2 = .1 so p= sqrt(.1) 2. P = .6, what is q2? q = .4, q2 = .16 Four processes of microevolution 1. Natural selection – survival of the fittest, five modes of natural selection a. Directional selection – shifts all the population to resemble the bugs with the immunity, right or left b. Stabilizing selection – there is a tendency to be the median. Props it like a tent, or the standard size nut then makes for the median beak. c. Disruptive selection – selection prefers the extremes. Median dies out. d. Balancing selection – heterozygote are favored, 2 alleles are maintained in a population. Sickle cell an example
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: (AA normal targeted by malaria, Aa carrier but unaffected by both, aa sickle cell) e. Sexual selection traits develop that are only to help organism reproduce 2. Genetic drift change in allele frequency DUE TO CHANCE %%%, smaller populations more affected. a. Bottleneck effect a natural disaster happens and the population is reduced, the survivors are random. Losing both phenotypes and genotypes sometimes b. Founder affect whats important about this Is the isolation. An individual or a small group becomes isolated and then grows from there. 3. Gene flow travel of organisms between two populations (immigration and emigration). Stabilizing effect, counterintuitive to gene drfit 4. Mutation only creative force, may be good/bad/neutral....
View Full Document

This note was uploaded on 05/18/2011 for the course BIOL 101 taught by Professor Hogan during the Spring '08 term at UNC.

Ask a homework question - tutors are online