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22 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Speciation |
the formation of new and distinct species in the course of evolution |
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Microevolution |
evolutionary change within a species or small group of organisms, especially over a short period |
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Macroevolution |
major evolutionary change. The term applies mainly to the evolution of whole taxonomic groups over long periods of time |
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Biological species concept |
most widely accepted species concept. It defines species in terms of interbreeding |
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Reproductive isolation |
collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation |
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Prezygotic barriers |
a mechanism that prevents fertilization from occurring |
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Postzygotic barriers |
mechanism that reduces the viability or reproductive capacity of hybrid offspring |
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Habitat isolation |
2 species live in the same area but different habitats |
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Behavioral isolation |
Two allopatric species do not mate because of differences in courtship behavior |
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Temporal isolation |
mechanism that prevents species from mating because they breed at different times. These differences can be time of day, season, or even different years |
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Mechanical isolation |
biological features that prevent different species from interbreeding are called reproductive barriers |
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Gametic isolation |
a type of prezygotic barrier where the gametes come into contact, but no fertilization takes place |
Egg & sperm |
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Reduced hybrid viability |
hydrid individual is sterile often due to the inability to produce normal gametes in meiosis. Hybrid Breakdown. The first-generation hybrids are viable and fertile, but when they mate the offspring are feeble and sterile |
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Reduced hybrid fertility |
Some first-generation hybrids are fertile, but when they mate with another species or with either parent species, offspring of the next generation are feeble or sterile |
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Hybrid breakdown |
is a type of reproductive failure that appears after the F2 generation of crosses between different species or subspecies |
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Allopatric speciation |
speciation that occurs when biological populations of the same species become vicariant, or isolated from each other to an extent that prevents or interferes with genetic interchange |
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Sympatric speciation |
the process through which new species evolve from a single ancestral species while inhabiting the same geographic region |
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Autopolyploid |
an individual or strain whose chromosome complement consists of more than two complete copies of the genome of a single ancestral species |
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Allopolyploid |
an individual or strain whose chromosomes are composed of more than two genomes each of which has been derived more or less complete but possibly modified from one of two or more species |
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Adaptive radiation |
the diversification of a group of organisms into forms filling different ecological niches |
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Gradualism |
the hypothesis that evolution proceeds chiefly by the accumulation of gradual changes |
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Punctuated equilibrium |
the hypothesis that evolutionary development is marked by isolated episodes of rapid speciation between long periods of little or no change |
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