Studied by 100 peopleadaptation
an inherited characteristic that can be either physical or behavioral
adaptive radiation
diversification of a species into a number of different species over a relatively short time span
allopatric speciation
occurs when a population divided by a geographic barrier evolves into two or more populations
analogous structure
same function but different structure that is not inherited from a common ancestor;
ancestrial trait
more-primitive characteristic that appeared in common ancestors
artificial selection
selective breeding to produce desired traits
biogeography
study of the distribution of plants and animals on earth
bottleneck effect
process in which a large population declines in number and rebounds but with much less genetic diversity
camouflage
morphological adaptations that allow organisms to blend into their surroundings
comparative embryology
vertebrate organism's early prebirth structures are similar during development but become different as adults
convergent evolution
the evolution of species to have similar anatomy without coming from a common ancestor
derived trait
new feature that had not appeared in common ancestors
directional selection
shift of a population toward an extreme version of a beneficial trait
disruptive selection
process in which individuals with average traits are removed creating two populations with extreme traits
divergent evolution
the evolution of two species that become increasingly different
evidence of evolution
fossil record, comparative anatomy,.comparative embryology, comparative biochemistry
evolution
hereditary changes in groups of living organisms over time
fitness
The ability of an individual to survive and reproduce in its specific environment
fossils
Preserved remains of once-living organisms
founder effect
can occur when a small population settles in an area separated from the rest of the population and interbreeds
gene flow
exchange of genes between populations
genetic drift
random change in allelic frequencies in a population
genetic equilibrium
situation in which allele frequencies remain constant
gradualism
theory that evolution occurs in gradual steps over time
half-life
length of time required for half of the radioactive atoms in a sample to decay
Hardy-Weinberg principle
allelic frequencies in populations stay the same unless they are affected by a factor that causes change
homologous structure
similar structure inherited from a common ancestor
hox gene
a group of genes that determine the head to tail identity of body parts in animals.
mimicry
morphological adaptation in which one species evolves to resemble another species for protection
natural selection
theory of evolution developed by Darwin, based on four ideas: individuals show variations, variations are inherited, excess reproduction, and the advantages of specific traits in an environment
punctuated equilibrium
theory that evolution occurs with relatively sudden periods of speciation followed by long periods of stability
sexual selection
change in the frequency of a trait based on the ability to attract a mate
speciation
Formation of new species
stabilizing selection
most common form of natural selection in which organisms with extreme expressions of a trait are removed
survival of the fittest
individuals that are better suited to their environment survive and the ones that are not die.
sympatric speciation
occurs when a species evolves into a new species in an area without a geographic barrier
vestigial structure
smaller or reduced form of a functional structure that indicates shared ancestry
Note
Flashcard