Natural Selection and Microevolution Flashcards
Viable
Able to survive and reproduce.
Fecundity
The natural capability to produce offspring.
Microevolution
A change in gene frequency within a population over successive generations.
Gene Pool
Total aggregate of genes in a population at any one time.
Stabilising Selection
Natural selection for a particular variant (mean) of a characteristic that maintains consistency of a population; occurs in times of environmental stability.
Directional Selection
Natural selection that favours one phenotypic extreme causing the allele frequency to shift over time in the direction of that phenotype.
Disruptive Selection
Natural selection favouring individuals with extreme phenotypes.
Genetic Equilibrium
Describes the condition of an allele or genotype in a population when the frequency remains stable over time.
Hardy-Weinberg Law
States that there are no other evolutionary influences, the allele and genotype frequencies in a population will remain constant across generations.
Gene Flow
The movement and exchange of alleles between populations of a species.
Genetic Drift
Changes in the gene pool, and thus relative frequency of different genotypes in a small population, due to chance.
Natural Evolution
Evolutionary changes caused by genetic drift (dominated by random processes) rather than natural selection.
Founder Effect
Reduced genetic diversity as a result of a population having descended from a small number of colonising ancestors.
Population Bottleneck
An event (environmental disaster, overhunting, etc.) that drastically reduces the size of a population and this its genetic diversity.
