BIOL 1010 Lecture Notes - Lecture 2: Vkorc1, Warfarin, Pesticide Resistance
Document Summary
Examples of directional selection : e. g. 1) warfarin resistance in rats: Warfarin interferes with synthesis of blood-clotting agents bleeding death. Mutations in a gene (encodes vkorc1) associated with warfarin resistnace. Resistance increases rapidly in populations after poisoning programs introduced. Editing rather than creative mechanism (needs variation to act on) Contingent on time and place (adaptation to the particular environment) e. g. the gee variants that confer warfarin resistance happen to be disadvantageous when poison not being used. e. g. 2) soapberry bugs: Bug feeding on fruit of original host species. Shorter beaks are favoured: avg. beak length in population falls. Evidence for a tree-of life, and descent with modification. Examples: homology: similarity resulting from common ancestry. 1- forelimbs of mammals: common form despite different functions. 2- vestigial structures: structures with little or no function, derived from more complex structures. 3- molecular homologies: homologies at the biochemical level.
