BILD 3 Lecture Notes - Lecture 5: Macroevolution, Bild, Microevolution
Document Summary
Change in the genetic composition of a population across generations. The allele frequency is 20% brown and 80% green. After 1 year, there is 40% brown and 60% green. The beetles that are brown have selection for the brown allele for camouflage. Immigration or emigration (brown beetles coming in or green beetles coming out) Genetic drift (a random process that some beetles happen to have more babies than others; just by chance) Mutations (some green allele mutating and becomes brown) Macroevolution: change in the composition of species over time. We reconstruct this using evidence from geology, fossils, and dna from living organisms. A fossil is any trace of an organism that lived in the past. Usually found in sedimentary rocks, which are made of sediment. Most of the fossils are marine animals because it is harder for animals to be fossilized on land.