ANTHRO 7 Lecture Notes - Lecture 4: Gorilla, Genetic Drift, Hadrosaurid
Document Summary
Week 2: lecture 7- population genetics, molecular genetics, and systematics. Now we can understand how the modern synthesis explains: How variation is maintained even when selection is strong. How selection can move a species outside its original range of variation. Most traits are polygenic -> affected by >1 locus. Consider a trait, body size, affected by 10 loci, each with 2 alleles. Another way to have a very small body. Variation is continuous, and is maintained even in the face of strong selection. Genes are discrete, but the phenotypic variation produced is nearly continuous (21 different levels of body size) And since body size is affected by environment as well as by genes (the same genotype produces different phenotypes depending on e. g, nutrition), the 21 levels will blend into a continuous range of variation in size. Not a limited set of discrete variables.
