BIOL108 Lecture Notes - Lecture 7: Species, Allopatric Speciation, Reproductive Isolation

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Lien Luong

Document Summary

Defines a species as a group of actually or potentially interbreeding individuals that are reproductively isolated from other such groups focuses on reproductive compatibility therefore define species = closed gene pool. Only applies to sexually reproducing species, neglecting the asexual species. Suggests that 2 different species would never mate and produce offspring (but exceptions do exist- successful hybridization) Ecological species concept: a species is a set of organisms adapted to a particular set of resources, called a niche, in the environment. Phylogenetic species concept: this concept defines species by looking at their evolutionary history. Prezygotic isolation mechanisms temporal isolation (mating at different times of day / season) Ecological / habitat selection (e. g. tree canopy vs. grass) Gamete isolation (sperm & egg cannot fuse) F1 hybrid sterility (healthy but unable to reproduce) F2 fitness (hybrid"s offspring being sterile & having lower fitness.