Biology Ch. 15 Vocabulary Flashcards
Darwin’s term for the selective breeding of organisms selected for certain traits in order to produce offspring having those traits
Artificial selection
Theory of evolution developed by Darwin, based on four ideas: excess reproduction, variations, inheritance, and the advantages of specific traits in an environment
Natural selection
Hereditary changes in groups of living organisms over time
Evolution
New feature that had not appeared in common ancestors
Derived trait
More-primitive characteristic that appeared in common ancestors
Ancestral trait
Anatomically similar structure inherited from a common ancestor
Homologous structure
Reduced form of a functional structure that indicates shared ancestry
Vestigial structure
Structure that has the same function but different construction and was not inherited from a common ancestor
Analogous structure
Organism’s early pre birth stage of development
Embryo
Study of the distribution of plants and animals on Earth
Biogeography
Measure of a trait’s relative contribution to the following generation
Fitness
Morphological adaptations that allow organisms to blend into their surroundings
Camouflage
Morphological adaptation in which one species evolves to resemble another species for protection or other advantages
Mimicry
Random change in allelic frequencies in a population
Genetic drift
Random effect that can occur when a small population settles in an area separated from the rest of the population and interbreeds, producing unique allelic variations
Founder effect
Change in the frequency of a trait based on competition for a mate
Sexual selection
Most common form of natural selection in which organisms with extreme expressions of a trait are removed
Stabilizing selection
Shift of a population toward an extreme version of a beneficial trait
Directional selection
Process in which individuals with average traits are removed, creating two populations with extreme traits
Disruptive selection
Factor that prevents individuals from different species from mating: operates before fertilization
Prezygotic isolating mechanism
Factor that prevents a hybrid zygote from developing, or prevents hybrid offspring from reproducing, operates after fertilization
Postzygotic isolating mechanism
Occurs when a population divided by a geographic barrier evolves into two or more populations unable to interbreed
Allopatric speciation
Occurs when a species evolves into a new species in an area without a geographic barrier
Sympatric speciation
Diversification of a species into a number of different species, often over a relatively short time span
Adaptive radiation
Theory that evolution occurs in small, gradual steps over time
Gradualism
Theory that evolution occurs with relatively sudden periods of speciations followed by long periods of stability
Punctuated equilibrium
