Chapter 15 Vocabulary - The Theory of Evolution Flashcards
Adaptation
a heritable trait that improves an organism’s chances of surviving and producing offspring
Biogeography
the study of patterns in the geographic distribution of species and communities
Fitness
a measure of an individual’s ability to survive and produce offspring relative to other members of its population
Natural Selection
a major mechanism of evolution: the differential survival and reproduction of individuals of a population based on differences in shared, heritable traits; outcome of environmental pressures
Allele Frequency
the proportion of one allele relative to all the alleles for that trait in a population’s chromosomes
Directional Selection
a mode of natural selection in which forms of a trait at one end of a range of variation are adaptive
Disruptive Selection
a mode of natural selection in which forms of a trait at both ends of a range of variation are adaptive, and intermediate forms are selected against
Gene Pool
all the alleles of all the genes in a population; a pool of genetic resources
Stabilizing Selection
a mode of natural selection in which an intermediate form of a trait is adaptive, and extreme forms are selected against
Bottleneck Effect
a reduction in population size so severe that it reduces genetic diversity; a type of genetic drift
Founder Effect
a reduction in genetic variation that results from a small population colonizing a new area; a type of genetic drift
Gene Flow
the movement of alleles between populations
Genetic Drift
a change in allele frequency due to chance alone
Sexual Selection
a mode of natural selection in which some individuals out reproduce others of a population because they are better at securing mates
