Evo study vocab part 4 April 9th

·       Biological species concept –

 

species are groups of potentially interbreeding populations that are reproductively isolated from other such groups

– Works pretty well for sexually reproducing animals

·       General lineage species concept –

species are metapopulations that exchange alleles frequently enough to comprise the same gene pool

·       Phylogenetic species concept –

smallest possible group descending from a common ancestor and recognizable by unique, derived traits

– Useful for systematics; focuses on phylogenetic history

·       Reinforcement –

natural selection favors prezygotic isolation mechanisms that prevent the formation of hybrids with reduced fitness

– Postzygotic isolation must evolve in allopatry

·       metapopulation -

is a group of spatially separated populations of the same species that interact at some level (for example, exchange alleles).

 isolating barrier -

refers to an aspect of the environment, genetics, behavior, physiology, or ecology of a species that reduces or impedes gene flow from individuals of other species. Isolating barriers can be geographic or reproductive

·       Allopatry -

occurs when populations are in separate, nonoverlapping geographic areas (that is, they are separated by geographic barriers to gene flow).

·       Habitat isolation -

 is a prezygotic isolating mechanism where two or more species occupy different habitats or ecological niches within the same general area, preventing them from meeting and interbreeding

·       Reproductive isolation -

occurs when reproductive barriers prevent or strongly limit reproduction between populations. The result is that few or no genes are exchanged between the populations.

·       prezygotic reproductive barrier -

is an aspect of the genetics, behavior, physiology, or ecology of a species that prevents sperm from one species from fertilizing eggs of another species. Prezygotic barriers reduce the likelihood that a zygote will form.

·       postzygotic reproductive barrier -

is an aspect of the genetics, behavior, physiology, or ecology of a species that prevents hybrid zygotes from successfully developing and reproducing themselves

·       Allopatric speciation -

is the evolution of new species after populations have been separated geographically, preventing gene flow between them.

·       Sympatric speciation -

is the evolution of new species within a contiguous population that still has extensive gene flow.

·       Parapatric speciation -

is the evolution of new species within a spatially extended population that still has some gene flow.

·       Magic traits –

is a trait that simultaneously confers ecological divergence and reproductive isolation.