BIOL 1003 Lecture Notes - Lecture 1: Tasmanian Devil, Genetic Drift, Comparative Anatomy
Document Summary
Biol 1003 week 1 lecture 2. Evidence for evolution: fossil record, comparative anatomy and embryology. Homologies, analogies, vestigia: comparative biochemistry, biogeography, dna. Natural selection: needs variation, heritability, & differential fitness, works on individuals don"t evolve traits based on need, requires variation, leads to adaptation fitness currency of natural selection. Fitness (w) = # of offspring / largest # of offspring. Founder effect: small portion of a population splits off and forms a new population that is less diverse than original population. Ex: tasmanian devil extreme lack of genetic diversity similar immune systems susceptible to similar pathogens spreading of contagious tumor called devil facial tumor disease (dftd) spread through. Bottleneck effect: population"s size is reduced (very small) for at least one generation by event; population grows back but with a lot less diversity. Proximate cause physiological and hormonal reasons that giraffe"s necks grow long. Ultimate cause evolutionary reason; adaptive significance. Adaptive feature has evolved by natural selection.
