Download adaptation: genetically determined characteristic (behavioral

KEY TERMS FOR LAB EXERCISE 4:
adaptation: genetically determined characteristic (behavioral, morphological,
physiological) that improves an organism's ability to survive and successfully reproduce
under prevailing environmental conditions.
allele frequency: the proportion of a particular allele present in the members of a
population for a particular trait.
allopatric speciation: a mode of speciation induced when the ancestral population
becomes segregated by a geographic barrier.
allopatric: having different areas of geographical distribution; possessing
nonoverlapping ranges.
bottleneck: an evolutionary term for any stressful situation that greatly reduces a
population. In other words, is the genetic drift resulting from the reduction of a
population, typically by a natural disaster, such that the surviving population is no longer
genetically representative of the original population.
evolution: all of the changes that have transformed life on Earth from its earliest
beginnings to the diversity that characterizes it today.
fitness: genetic contribution by an individual's descendants to future generations. In other
words, the contribution an individual makes to the gene pool of the next generation,
relative to the contributions of other individuals.
fixation index: a measure of the reduction of heterozygosity of a subpopulation due to
random genetic drift.
founder effect: genetic drift attributable to colonization by a limited number of
individuals from a parent population.
gamete: a sex cell; in other words, a haploid egg or a sperm cell.
gene flow: exchange of genetic material between populations.
gene pool: the sum of all the genes of all individuals in a population.
genetic drift: random fluctuation in allele frequency over time due to chance occurrence
alone without any influence by natural selection. Important in small populations.
Hardy-Weinberg theorem: an axiom maintaining that the sexual shuffling of genes
alone cannot alter the overall genetic makeup of a population.
inbreeding: mating among close relatives.
macroevolution: evolutionary change on a grand scale, encompassing the origin of new
taxonomic groups, evolutionary trends, adaptive radiation, and mass extinction.
microevolution: generation–to–generation change in the frequencies of alleles and
genotypes in a population—a change in the population's genetic structure.
migration: intentional, directional, usually seasonal movement of animals between two
regions or habitats; involves departure and return of the same individual; a round-trip
movement.
modern synthesis: A comprehensive theory of evolution emphasizing natural selection,
gradualism, and populations as the fundamental units of evolutionary change; also called
neo-Darwinism.
mutation: transmissible change in structure of a gene or chromosome. In other words, a
rare change in the DNA of a gene ultimately creating genetic diversity.
natural selection: differential reproduction and survival of individuals that results in
elimination of maladaptive traits from a population. In other words, differential success in
the reproduction of different phenotypes resulting from the interaction of organisms with
their environment. Evolution occurs when natural selection causes changes in relative
frequencies of alleles in the gene pool.
nonrandom mating: the selection of mates other than by chance.
population genetics: The study of genetic changes in populations; the science of
microevolutionary changes in populations.
population: group of individuals of the same species living in a given area at a given
time. The modern synthesis focuses on populations as units of evolution.
speciation The origin of new species in evolution.
species: a population or group of populations whose members have the potential in
nature to interbreed and produce fertile offspring. In other words, group whose members
possess similar anatomical characteristics and have the ability to
sympatric speciation: a mode of speciation occurring as a result of a radical change in
the genome that produces a reproductively isolated subpopulation in the midst of its
current population.