Evolution Flashcards
Directional
Form of selection that results in a progressive shift in a population’s mean value for a trait.
Disruptive
Form of selection that results in a population being split into two distinct groups, each with its own mean value for a trait.
Evolution
Process of gradual change in a population of organisms over successive generations resulting from genomic variations.
Allopatric
Form of speciation where gene flow between populations of a species is prevented by a geographical barrier.
Gene pool
Total of all the genomic sequences (alleles) present in the genotypes of the members of a species.
Isolating mechanism
Geographical, ecological or behavioural barrier that prevents genetic exchange between populations of a species.
Neutral
Type of mutation whose genetic sequence differs from the original but which still codes for the functional protein.
Selective advantage
Benefit gained by mutant organisms in an environment that suits them but not other members of the population.
Speciation
Generation of new biological species by evolution as a result of isolation, mutation and natural selection.
Species
Group of organisms that produce fertile offspring and share the same chromosome complement.
Sympatric
Form of speciation where gene flow between populations of a species is prevented by a behavioural or ecological barrier.