Module 47 Terms - Speciation Flashcards
Biological species concept
Species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups
Morphospecies concept
The members of the same species usually look alike, both at a morphological and molecular level
Niche
A complete description of the role a species plays in its environment and of its abiotic and biotic requirements
Prezygotic
Happen before the fertilization of an egg and prevent fertilization from taking place
Postzygotic
Happen after fertilization and prevent the fertilized egg from developing into a fertile individual
Geographic/ecological isolation
Physically separated, prezygotic
Temporal isolation
Isolated in time, prezygotic
Behavioral isolation
Individuals only mate based on specific behaviors, prezygotic
Gametic isolation
Incompatibility between the gametes of two different species, prezygotic
Mechanical isolation
Unable to physically mate, prezygotic
Hybrid inviability
Failure of hybrid to develop, postzygotic
Hybrid sterility
Viable hybrids that are sterile, postzygotic
Hybrid breakdown
Hybrid sterility only on 2nd generation, postzygotic
Speciation
The process by which new species are produced
Divergent evolution
When two populations of organisms become genetically and physically different from each other
Allopatric
Populations that are geographically separated from each other
Sympatric
Populations that are in the same geographic location
Adaptive radiation
A bout of unusually rapid evolutionary diversification in which natural selection accelerates the rates of both speciation and adaptation
Gradualism
A model in which species change slowly over time, adapting to environments that are changing slowly
Punctuated equilibrium
A model in which there are periods of relatively little change, followed by periods of rapid diversification
