ANP 443 Lecture Notes - Lecture 20: Reproductive Isolation, Gene Flow, Directional Selection
Document Summary
Biological species concept a species consists of populations of organisms that can reproduce with one another and that are reproductively isolated from other populations. > members of a species evolve as a unit. Ecological species concept a species is a set of organisms adapted to a particular set of resources, called a niche, in the environment. > the hybrids that are born have no advantage/ has a disadvantage. Allopatric speciation biological populations of the same species become isolated from each other to an extent that prevents or interferes with genetic interchange. Parapatric speciation two subpopulations of a species evolve reproductive isolation from one another while continuing to exchange genes. Species remain unchanged and then undergo rapid, major change. Adaptive radiation a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
