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20 Cards in this Set
- Front
- Back
Species |
Basic taxonomic units of biological classification |
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Biological species concept |
Actually or potentially interbreeding natural populations which are reproductively isolated from other such groups |
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Reproductive isolating mechanisms |
Premating Postmating Postzygotic |
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Premating isolating mechanisms |
Ecological isolation Temporal isolation Behavioural isolation Mechanical isolation |
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Postmating or prezygotic isolating mechanisms |
Gametic isolation |
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Postzygotic isolating mechanisms |
Hybrid inviability Hybrid sterility |
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Haldane’s Rule |
When fitness differs b/w the sexes of hybrid offspring, the heterogametic sex has lower fitness |
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Speciation |
Splitting of a single ancestral species into two or more descendant species |
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Allopatric Speciation |
New species forms geographically apart from its ancestors |
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Parapatric Speciation |
New species form in a geographically contiguous population |
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Sympatric speciation |
A new species emerees from with the geographic range of its ancestors |
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Hybrid zones |
Regions in which previously isolated populations come into contact and produce hybrids |
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Sympatric speciation how.? |
Selection against individuals of an intermediate type |
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Anagenesis |
Progressive evolution of species involving a gradual change in traits in an entire population |
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Cladogenesis |
Evolutionary splitting event in a population of a soecies into two or more sister species |
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Adaptive Radiation |
Smaller number of ancestral species diversifies into a larger number of descendant species in a relatively short time |
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Macroevolution |
Evolution occurring above the species level. |
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Punctuated equilibrium |
Periods of stasis puntuated by brief periods of rapid change |
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Stasis |
Little or no directional change |
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Phyletic Gradualism |
Evolution has a fairly constant rate. New species through anagenesis |