BIOL 105 Lecture Notes - Lecture 9: Quantitative Genetics, Directional Selection, Fecundity
Document Summary
Outline: definitions of heritability, breeder"s equation, phenotypic variation, narrow & broad sense heritability, quantitative genetics studies the mode of inheritance. It looks at the phenotypes that can be observed such as height or mass. Breeder"s equation (ii: adaptive phenotypic evolution consists of 2 parts: Inheritance (h^2: selection (s) r = response to selection. Phenotypic evolution from one generation to the next! Change in the phenotypic mean of a population from one generation to the next: h^2 = narrow-sense heritability. How much of the population variation in a population is caused by genetic effects that can be passed on from parents to their offspring. s = directional selection differential. Difference in mean phenotype between the original whole population before selection and the mean of the individuals who actually breed to produce the next generation. Indicates the strength of selection acting to change (increase) the average value of a trait.
