BIOB51H3 Lecture Notes - Lecture 19: Natural Selection, Quantitative Genetics, Daniel Craig
Document Summary
Heritability is not a fixed feature of a trait (fact) Variation due to genes and variation due to the environment. All of our traits are derived from our genes acting on to the environment. If you change environmental variation, than heritability will also change. This does not mean that the genes underlying the traits have changed. However, the expression of our genes will be affected by the environment. E. g skin colour among caucasian people in vancouver. Genetic variation causes alteration to skin colour, as well as exposure to the sun. If we assume random variation due to the environment (how much sun you are exposed to, when its sunny) If you look at parent-offspring regression under different environmental conditions, it changes. Most of the variation in skin tone in offspring is predicted by their parents, during the winter. In the summer, when ve is high, heritability is low.