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Concepts of Biology

Key Terms

Concepts of BiologyKey Terms

Key Terms

adaptation
a heritable trait or behavior in an organism that aids in its survival in its present environment
adaptive radiation
a speciation when one species radiates out to form several other species
allopatric speciation
a speciation that occurs via a geographic separation
analogous structure
a structure that is similar because of evolution in response to similar selection pressures resulting in convergent evolution, not similar because of descent from a common ancestor
bottleneck effect
the magnification of genetic drift as a result of natural events or catastrophes
convergent evolution
an evolution that results in similar forms on different species
dispersal
an allopatric speciation that occurs when a few members of a species move to a new geographical area
divergent evolution
an evolution that results in different forms in two species with a common ancestor
founder effect
a magnification of genetic drift in a small population that migrates away from a large parent population carrying with it an unrepresentative set of alleles
gene flow
the flow of alleles in and out of a population due to the migration of individuals or gametes
gene pool
all of the alleles carried by all of the individuals in the population
genetic drift
the effect of chance on a population’s gene pool
homologous structure
a structure that is similar because of descent from a common ancestor
inheritance of acquired characteristics
a phrase that describes the mechanism of evolution proposed by Lamarck in which traits acquired by individuals through use or disuse could be passed on to their offspring thus leading to evolutionary change in the population
macroevolution
a broader scale of evolutionary changes seen over paleontological time
microevolution
the changes in a population’s genetic structure (i.e., allele frequency)
migration
the movement of individuals of a population to a new location; in population genetics it refers to the movement of individuals and their alleles from one population to another, potentially changing allele frequencies in both the old and the new population
modern synthesis
the overarching evolutionary paradigm that took shape by the 1940s and is generally accepted today
natural selection
the greater relative survival and reproduction of individuals in a population that have favorable heritable traits, leading to evolutionary change
population genetics
the study of how selective forces change the allele frequencies in a population over time
speciation
a formation of a new species
sympatric speciation
a speciation that occurs in the same geographic space
variation
the variety of alleles in a population
vestigial structure
a physical structure present in an organism but that has no apparent function and appears to be from a functional structure in a distant ancestor
vicariance
an allopatric speciation that occurs when something in the environment separates organisms of the same species into separate groups
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