 | Term | Definition |
| |
Macroevolution |
large scale modifications that occur over long time periods and produce new species |
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Mass Extinction |
one of a brief period of time during which large numbers of species disappeared |
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Relative Dating |
A procedure for comparing the amount of a radioactive isotope and its decay product to determine the age of a geologic specimen |
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Radioactive Dating |
A method of determining the age of an object by measuring the amount of a specific radioactive isotope it contains |
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Microevolution |
small scale modifications that occur over short periods and result in a change in gene frequency within a population |
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Homologous |
similar feature originated in a shared ancestor |
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Vestigial |
name of the functionless structure that was functional in an ancestral species |
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Fitness |
a measurement of the ability of a species to respond to the pressures of natural selection and produce the most viable offspring |
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Adaptation |
an inherited trait that increases an organisms chance of survival in a particular environment |
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Survival of the Fittest |
the individuals capable of producing the most viable offspring in a population |
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Natural Selection |
the process by which organims with favorable variations reproduce at higher rates than those without such variations |
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Evolution |
descent with modification |
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Convergent Evolution |
the process by which unrelated species become more similar as they adapt to the same kind of environment |
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Divergent Evolution |
the process of two or more related species becoming more and more dissimilar |
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Adaptive Radiation |
an evolutionary pattern in which many species evolve from a single ancestral species |
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Disruptive Selection |
a type of natural selection in which individuals with two extreme forms of a trait have an advantage |
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Directional Selection |
individuals that display a more EXTREME form of a trait have greater fitness |
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Stabilizing Selection |
a type of natural selection in which the average form of a trait causes an organism to have an advantage in reproduction |
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Gene Pool |
all the genes for all of the traits in a population |
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Relative Frequency |
the abundance of one form of a gene or trait compared to an alternative form of the same gene or trait. |
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Genetic Drift |
a shift of allele frequencies in a population due to random chance |
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Founder Effect |
occurs when a new population is established by a relatively few individuals |
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Hardy-Weinberg Principle |
principle stating the stability of gene frequencies across generations |
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Genetic Equilibrium |
alternate forms of a trait have equal frequencies ex. p=50% q=50% |
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Reproductive Isolation |
the inability of formerly interbreeding organisms to produce viable offspring |
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Analogous |
structures that are similar in appearance and function but have different ancestral origin |
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Speciation |
the formation of a new species |
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Punctuated Equilibrium |
a theory that speciation occurs during brief periods of rapid genetic change |
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Coevolution |
the mutual modification of two different species interacting with each other |
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Sexual Selection |
the preferential choice of a mate based on a specific phenotypic trait |
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Uniformitarianism |
principle that says geological structure of the earth resuited from cycles of observetable processes and that the same process operate continually through time |
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Endosymbiosis |
a theory of the evolution of eukaryotes by the formation of a mutualistic relationship between two prokaryotes |
