BLG 144 Lecture Notes - Lecture 3: Phylogenetics, Anagenesis, Cladogenesis
Document Summary
Microevolution change in gene pool; four evolutionary mechanism acting on it. Anagenesis (phyletic) accumulation (not adaptation) transforms species; change but no evolution. Cladogenesis (branching) one split to form another = increase in # of species. What is a species: biological interbreeding = making viable offspring; separateness of species. Two types of reproductive isolation (barriers): prezygotic stops two different species from mating, postzygotic stops hybrid from becoming an adult, morphological body size/shape/structure, ecological niche (role in ecosystem, phylogenetic evolutionary history of orgs (separates or unifies groups of orgs) Gene flow pop move from one place to the other; homos: allopatric physical isolation. Vicarance physical barrier + dispersal colonies = new pop: sympatric physical overlap. Niche + microhabitat (i. e. , fruit flies in red apple vs. green) Plant speciation = special b/c mutation give rise to extra chromosomes sets. Chromosome has to match if not sterile/self-fertilize.
