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