BIOC16H3 Lecture Notes - Lecture 7: Phenotypic Plasticity, Phenotypic Trait, Sexual Dimorphism
Document Summary
We want to understand phenotypic variation in outbreeding species! To do this we estimate variances and heritability"s using phenotypic measurements of individuals with known genetic relationships! Need an adequate number of monogamously mated pairs for the parental generation! Always go for more families than more siblings ! Measure the trait in one or both parents! Rear offspring to some developmental stage at which parents were measured! If slope = 1 then a parental increase of 1leads to an offspring increase of 1! If slope = 0. 5 then a parental increase of 1 leads to an offspring increase of 0. 5! Therefore only half of the phenotypic variance is additive genetic variance!!! Therefore it doesn"t contribute to resemblance of parents and offspring! Because of the environment and non additive genetic variance, it is expressed in the variance among full siblings within each family. You remove this variance by using a single mean of the offspring rather than individual offspring values.