Evolution Of Population Flashcards
Gene Pool
collection of alleles found in all of the individuals of a population
Allele Frequency
Proportion of one allele, compared with all the alleles for heat trait, in the gene pool
Normal Distribution
distribution in a population in which allele frequency is highest near the mean range value and decreases progressively toward each extreme end
Microevolution
observable change in the allele frequencies of a population over a few generations
Directional Selection
Pathway of natural selection in which one uncommon phenotype is selected over a more common phenotype
Stabilizing Selection
pathway of natural selection selection in which intermediate phenotypes are selected over phenotypes at both extremes
Disruptive Selection
Pathway of natural selection in which two opposite, but equally uncommon, phenotypes are selected over the most common phenotypes
Gene Flow
physical movement of alleles from one population to another
Genetic Drift
change in allele frequencies due to chances alone, occurring most commonly in small populations
Bottleneck Effect
genetic drift that results from an event that drastically reduces the size of a population
Founder Effect
genetic drift that occurs after a small number of individuals colonize a new area
Sexual Selection
selection in which certain traits enhance mating success; traits are, therefore, passed onto offspring
Reproductive Isolation
final stage in speciation, in which members of isolated populations are either no longer able to mate or no longer able to produce viable offspring
Speciation
evolution of two or more species from one ancestral species
Behavioral Isolation
isolation between populations due to differences in courtship or mating behavior
Geographic Isolation
isolation between populations due to physical barriers
Temporal Isolation
isolation between populations due to barriers related to time, such as differences in mating period or differences in the time of day that individuals are most active
Convergent Evolution
evolution towards similar characteristics in unrelated species, resulting from adaptations to similar environmental conditions
Divergent Evolution
evolution of one or more closely related species into different species; resulting from adaptation to different environmental conditions
Coevolution
process in which two or more species evolve in response to changes in each other
Extinction
elimination of a species from Earth
Punctuated Equilibrium
theory that states that speciation occurs suddenly and rapidly followed by long periods of little evolutionary change
Adaptive Radiation
process by which one species evolves and gives rise to many descendant species that occupy different ecological niches