LIFE 102 Lecture Notes - Lecture 24: Alpheidae, Species Problem, Sympatric Speciation
Document Summary
Speciation- the process by which one species diverges into 2 or more species. Different species can appear to be identical. Violated by hybrids and other complex situations. Morphological species concept- species distinguished by morphological features. Criteria here are subjective, although morphologies are functionally how species are identified in the field. Ecological species concept- species distinguished by ecological roles, or niches. This species concept can be applied to asexually reproducing organisms and may be able to capture speciation in progress during ecological differentiation with gene flow. Phylogenetic species concept- species identified as smallest group of organisms that share a most recent common ancestor. Gene flow- the transfer of alleles between populations via migration of individuals. Relatively low levels of gene flow act to keep gene pools very similar. Prezygotic barriers: previous to mating, between mating and fertilization. Allopatric speciation- (other country) gene flow is interrupted by geographic isolation i. e. : snapping shrimp and isthmus of panama.
