mechanisms of evolution Flashcards
gene pool
total of all alleles within the population
allele frequency
The % of each allele of a given gene in the population. It determines the genetic
characteristic of that population
microevolution
Changing percentages or frequencies of alleles within populations leads to evolution within a
population.
what are the factors that cause evolutionary change
Mutation, gene flow, non-random mating, genetic drift, natural selection
gene flow
The net movement of alleles from one population to another as a result of migration of
the individuals
- When individuals move from one population to another, they alter the allele frequency of both populations.
non-random mating
Mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding
particular phenotype
choosing mates based on physical and behavioural traits
inbreeding
closely related individuals breed together; pure bred animals have a higher incidence of deformities and health problems
genetic drift
change in frequency of alleles due to chance events in a breeding population
founder effect
a change in gene pool that results when a few individuals start a new isolated population
bottleneck effect
changes in gene distribution that results from a rapid decrease in population size
natural selection
process that results when the characteristics of a population of organisms change over many generations due to biotic or abiotic factors.
what are the three types of selection?
stabilizing, directional, disruptive selection
stabilizing selection
favours an intermediate phenotype and selects against extreme variants of the phenotype; (grey mice are the intermediate phenotype of black and white mice)
directional selection
favours phenotypes at one extreme over the other
