AN202 Lecture Notes - Lecture 17: Genetic Drift
Document Summary
General relationship between body size and temperature: warmer = slender, colder = robust allen"s rule: General relationship between limb proportions and temperature: warmer = longer limbs, colder = shorter limbs. A trait may become common or rare in a population due to chance such effects are referred to as genetic drift. Part of a breeding population branches off as a new population (ex. colony) rare traits may be absent from or overrepresented in new population. Result may be group of related but different populations in a region. Part of a breeding population dies in a catastrophe. By chance, most individuals with a trait may die or survive. Population now has a different proportion of that trait than before the catastrophe. Sexual selection: a form of natural selection, individuals with most attractive traits mate more often o traits may be practical, traits may be impractical.
