ANTHR 101 Chapter Notes - Chapter 7: Liger, Ecological Niche, Cichlid
Document Summary
Microevolution: small changes occurring within a species, such as changes in allele frequencies. Macroevolution: large changes produced after many generations, such as the appearance of new species. Groups of inter-breeding natural populations, which are reproductively isolated from other such groups. Help along he speciation process once it has starts. Mechanical isolation: incompatibility in male and female sexual organs. Various post-mating mechanisms: antibody to sperm; sterile offspring. When there are 3 species living in close proximity, there is a lot of competition. Recognition species concept: emphasizes unique traits of behaviors that allow individual members of the same species to recognize each other for the purposes of mating. Ecological species concept: a group of organisms exploiting a single ecological niche. Evolutionary species concept: defines species as evolutionary lineages (ancestral-descendant sequences of populations) with their own unique identity. Cladogenesis: splitting of two lineages into two or more distinct lineages. Allopatric speciation: speciation occurring via complete geographic isolation.
