BISC 121Lg Lecture Notes - Lecture 5: Quantitative Trait Locus, Null Hypothesis, Aneuploidy
Document Summary
Polygenic inheritance- many genes controlling the expression of a quantitative trait: height is an example. Pleiotropic effects- a single gene mutation affects many phenotypic traits. Epistasis- a gene at one locus alters the phenotypic expression of a gene at a second locus. Linked genes- genes that tend to be inherited together. Polyploidy- 2 or more complete sets of chromosomes. Hardy-weinberg equilibrium conditions: 1) random mating/fertilization, 2) very large population size, 3) no natural selection, 4) no migration, 5) no mutation if these conditions are not met, then evolution occurs. Hardy-weinberg establishes a null hypothesis to test if evolution is occurring and the pace at which it is occurring. Frequencies of alleles and genotypes remain constant over generations in hardy- P + q = 1 and p2 + q2 = 1: p is the dominant allele, q is the recessive allele. Microevolution is the slow progression of individuals in a species diverging from one another.
