Chapter 21: Microevolution Flashcards
What is microevolution?
a heritable change in the genetic of a population
What is a population?
all the individuals of a single species that live together in the same place and time
What is phenotypic variation?
differences in appearance or function that are passed from generation to generation
What is a gene pool?
all the gene copies at all gene loci in all individuals in the population
What are the 5 conditions that must be met to achieve hardy-weinberg equilibrium?
1) no mutations are occurring
2) the population is closed to migration
3) the population is infinite in size
4) all genotypes survive and reproduce equally well
5) individual mate randomly with respect to genotypes
What causes microevolution?
1) mutations
2) gene flow
3) genetic drift
4) natural selection
5) nonrandom mating
What is a mutation?
spontaneous and heritable change in DNA
What is gene flow?
movement of organisms or their gametes from one population to another
What is genetic drift?
chance events (founder effects and population bottleneck) that change the allele frequencies in a population
What is a population bottleneck?
a dramatic reduction in population size
What is the founder effect?
change in the gene pool, few individuals start a new population
What is relative fitness?
number of surviving offspring that one produces in comparison to others in the population
What is sexual dimorphism?
difference in size or appearances of males and females
What is heterozygote advantage?
occurs when heterozygotes have higher relative fitness than either homozyogote
What is frequency-dependent selection?
rare phenotypes have a higher relative fitness than more common phenotypes
