LIFESCI 1 Lecture Notes - Lecture 7: Allopatric Speciation, Disruptive Selection, Genetic Drift
Document Summary
Speciation with no gene flow between diverging populations because of change in location. Peripatric speciation: dispersal with a small new population. Ancestral population seeds a small population more divergence in the small population occur because of genetic drift. Suggests faster genetic divergence on island populations. Relatively fast speciation as individuals leave the mainland, populate new areas, and diversify to fill the available niches. South america ancestor finch fly to new islands diversify to fulfill the roles of that niche in the islands multiple different species depending on each finch. Number of finch species increased with the number of islands. Suggests allopatric populations were important for speciation. The separation of habitats reduced gene flow between populations: enhances genetic isolation. Natural selection favored individuals that were more fit in new environment. Genetic drift occurred in the two populations. Organisms respond to changes happening in other organisms. Ex: pocket gophers and lice (hosts and parasites)
