ANT203H5 Lecture Notes - Lecture 4: Parapatric Speciation, Sympatric Speciation, Allopatric Speciation
Document Summary
Species = group of organisms exploiting a single ecological niche. Species split based on identifiable parental patterns of ancestry. See if same characteristic is in both animals. New species evolve too slowly to study in one lifetime (accept bacteria, some insects) New species evolve to quickly to study in the fossil record. Deduced that species could occur by: allopatric speciation, parapatric speciation, sympatric speciation. Geographic or environmental barriers isolate part of a population. Selection favors different phenotypes in these regions. Most common way of seeing speciation requires a physical barrier that isolates part of a population: disrupts gene flow. New species arise due to selection combined with partial genetic isolation. Hybrids less fit, so select for behaviour and morphology that reduces gene flow. All of situations like this in primate"s now. Happened in baboons and happening in some lemurs they are separated and limited amount of gene flow that allows the species to diverge.
