Evolution

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Evolution

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Darwin's theory implies that evolution has its roots in the small changing variations inherent in living things in addition to the sifting effects of natural selection. LAMARCK, in the 18th century, laid much emphasis on the potency of the influences of the external factors of use and disuse and environment on subsequent development.

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Artificial selection

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Selective breeding

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Natural selection

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the gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment.

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Adaption

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process by which an animal or plant species becomes fitted to its environment; it is the result of natural selection's acting upon heritable variation

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Fossil

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the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock

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Homologous

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similar in position, structure, and evolutionary origin but not necessarily in function.

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Speciation

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the formation of new and distinct species in the course of evolution

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Population

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a particular section, group, or type of people or animals living in an area or country

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Genetics

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the study of heredity and the variation of inherited characteristics

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Equilibrium

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a state in which opposing forces or influences are balanced

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Isolation

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the process or fact of isolating or being isolated

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Subspecies

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a taxonomic category that ranks below species, usually a fairly permanent geographically isolated race

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Divergence

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The accumulation of differences between groups which can lead to the formation of new species, usually a result of diffusion of the same species to different and isolated environments which blocks the gene flow among the distinct populations allowing differentiated fixation of characteristics through genetic drift and natural selection

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Speciation

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the evolutionary process by which new biological species arise

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Species

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a group of living organisms consisting of similar individuals

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Extinction

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the end of an organism or of a group of organisms

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Genetic Equilibrium

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describes the condition of an allele or genotype in a gene pool

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Gene Flow

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the transfer of alleles or genes from one population to another

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Genetic Drift

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the change in the frequency of a gene variant (allele) in a population due to random sampling

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Stabilizing Selection

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the opposite of disruptive selection. Instead of favoring individuals with extreme phenotypes, it favors the intermediate variants. It reduces phenotypic variation and maintains the status quo

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Disruptive Selection

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describes changes in population genetics in which extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups