BIOL 522 Lecture Notes - Lecture 8: Selective Sweep, Haplotype, Zygosity
Document Summary
Fitness = how an individual can survive/ contribute to the next generation, eg. number of offspring, measure of ensuring that the individual has a contribution to the next generation. Purifying selection/ background selection = natural selection to rid of deleterious mutations, can influence inferences about demographic history. Studies are almost always talking about positive selection - increase in prevalence in population/ increase in fitness. Directional selection = typically single variant in one per locus that rise in frequency. Diversifying selection = eg. hla, lots of variants adapt to have defense against infectious diseases. Directional selection = selection to be bigger/ smaller, related to individual variants, concepts are a little different. Focus more on positive selection because in this particular review paper looks at local adaptation - diff in phenotype. Purifying selection is everywhere, always purging deleterious mutations, positive selection on the other hand leaves a bright signal in one place.
