adaptation
process or trait that improves an organism’s ability to survive or reproduce in a given environment
allele
a version of a gene
allele frequency
the proportion of available slots at a given locus that have a particular allele
bottleneck effect
a type of genetic drift caused by a sharp decrease in population size; the gene pool of the remaining population may not reflect that of the original population
evolution
when defined narrowly, a change in gene frequencies within a population from one generation to the next
fitness
the number of surviving offspring that an individual contributes to the next generation
founder effect
a type of genetic drift in which a few individuals start a new population; the gene pool of the new population may not reflect that of the original population
gene flow
change in the gene pool caused by individuals entering or leaving a population
gene pool
the total set of alleles of all individuals in a population
genetic drift
the process by which random events cause random fluctuations in gene frequencies; these changes are not related to fitness or adaptation
genetic variation
differences among segments of DNA (through which traits are inherited) within a population
genotype
the genetic makeup of an organism
genotype frequency
the proportion of individuals in a population that have a particular genotype
Hardy-Weinberg equilibrium
the state of a population in which allele and genotype frequencies do not change between generations because evolution is not occurring
intersexual selection
a form of natural selection where mate choice by one sex results in different rates of success in reproduction between individuals
intrasexual selection
a form of natural selection where competition among individuals of same sex results in different rates of success in reproduction
locus (plural, loci)
the physical location of a gene on a chromosome
mutation
a change in DNA sequence
natural selection
a mechanism of evolution in which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do
population
an interbreeding group of individuals of the same species
sexual selection
a form of natural selection that focuses on reproduction, results from difference in reproductive success between individuals