behavioral isolation
isolation between populations due to differences in courtship or mating behavior
convergent evolution
evolution toward similar characteristics in unrelated species, resulting from adaptations to similar environmental conditions
speciation
evolution of two or more species from one ancestral species
genetic drift
change in allele frequencies due to chance alone, occurring most commonly in small polulations
adaptive radiation
process by which one species evolves and gives rise to many descendant species that occupy different ecological niches
divergent evolution
evolution of closely related species into different species
reproductive isolation
members of isolated populations are either no longer able to mate or no longer able to produce viable offspring
natural selection
mechanism by which individuals that have inherited beneficial adaptations produce more offspring than other individuals
punctuated equilibrium
theory that states that speciation occurs suddenly and rapidly, followed by long periods of little evolutionary change
geographic isolation
isolation between populations due to physical barriers
adaptation
inherited trait that is selected for over time because it allows organisms to better survive in their environment
phylogeny
evolutionary history of a group of related species
allele frequency
proportion of one allele, compared with all the alleles for that trait, in the gene pool
phenotype
collection of all of an organism's physical characteristics
biological resistance
the natural or genetic ability of an organism to avoid or repel attack by biotic agents or to withstand the effects of abiotic agents
biodiversity
variety of life within an area
directional selection
pathway of natural selection in which one uncommon phenotype is selected over a more common phenotype
disruptive selection
pathway of natural selection in which two opposite, but equally uncommon, phenotypes are selected over the most common phenotype
stabilizing selection
pathway of natural selection in which intermediate phenotypes are selected over phenotypes at both extremes
coevolution
process in which two or more species evolve in response to changes in each other
gradualism
principle that states that the changes in landforms result from slow changes over a long period of time
extinct
a species that has been eliminated from the Earth
mass extinction
a widespread and rapid decrease in the biodiversity on Earth
behavioral isolation
isolation between populations due to differences in courtship or mating behavior
convergent evolution
evolution toward similar characteristics in unrelated species, resulting from adaptations to similar environmental conditions
speciation
evolution of two or more species from one ancestral species
genetic drift
change in allele frequencies due to chance alone, occurring most commonly in small polulations
adaptive radiation
process by which one species evolves and gives rise to many descendant species that occupy different ecological niches
divergent evolution
evolution of closely related species into different species
reproductive isolation
members of isolated populations are either no longer able to mate or no longer able to produce viable offspring
natural selection
mechanism by which individuals that have inherited beneficial adaptations produce more offspring than other individuals
punctuated equilibrium
theory that states that speciation occurs suddenly and rapidly, followed by long periods of little evolutionary change
geographic isolation
isolation between populations due to physical barriers
adaptation
inherited trait that is selected for over time because it allows organisms to better survive in their environment
phylogeny
evolutionary history of a group of related species
allele frequency
proportion of one allele, compared with all the alleles for that trait, in the gene pool
phenotype
collection of all of an organism's physical characteristics
biological resistance
the natural or genetic ability of an organism to avoid or repel attack by biotic agents or to withstand the effects of abiotic agents
biodiversity
variety of life within an area
directional selection
pathway of natural selection in which one uncommon phenotype is selected over a more common phenotype
disruptive selection
pathway of natural selection in which two opposite, but equally uncommon, phenotypes are selected over the most common phenotype
stabilizing selection
pathway of natural selection in which intermediate phenotypes are selected over phenotypes at both extremes
coevolution
process in which two or more species evolve in response to changes in each other
gradualism
principle that states that the changes in landforms result from slow changes over a long period of time
extinct
a species that has been eliminated from the Earth
mass extinction
a widespread and rapid decrease in the biodiversity on Earth