BIOL 1104 Lecture Notes - Lecture 19: Allopatric Speciation, Sympatric Speciation, Alpheidae
20 Apr 2020
School
Department
Course
Professor
Document Summary
The denisovans are an extinct human species phylogenetically distinct from h. sapiens and neanderthals. The difficulty defining species is partly due to the diversity of reproductive modes, evolutionary history, and the isolation mechanisms involved. For instance recently diverged taxa are more likely to be difficult to defined as separate species than taxa that diverged a long time ago. Speciation can take place with or without geographic separation. Allopatric speciation: byproduct of being geographical isolation. Sympatric speciation: you might have gene flow that is maintained yet certain members of the population will start diverging (in the absence of physical barriers) Reproductive isolation can evolve as a by-product of selection in allopatric populations: in nature. Reproductive isolation can evolve as a by-product of selection in allopatric populations: in the lab. Examples of allopatric speciation in nature: snapping shrimps. 15 pairs of sister species of snapping shrimp (alpheus) are separated by.
