Create an account
Mutation that changes the base sequence of DNA, but the alteration has no effect on survival or reproduction--neither helps nor hurts the individual
The relative abundances of alleles of a given gene among all individuals of a population, starting from a theoretical reference point
A theoretical reference point which occurs when a population is not evolving with respect to the gene
Of a population or species, small-scale change in allele frequencies. Occurs by mutation, natural selection, genetic drift, gene flow
Differential survival and reproduction among individuals of a population that vary in the details of their shared traits. Influences the frequency of alleles in a population by operating on phenotypes that have a genetic basis.
Allele frequencies shift in a consistent direction, so forms at one end of a range of phenotypic variation become more common over time.
Forms of a trait at both ends of a range of variation are favored, and intermediate forms are selected against
Mode of natural selection in which some individuals, the genetic winners, out-reproduce others of a population because they are better at securing mates. Most adaptive forms of a trait are those that help individuals defeat same-sex rivals for mates, or are the ones most attractive to the opposite sex.
The maintenance of two or more alleles for a trait in some populations, as a result of natural selection against homozygotes
A form of bottlenecking. Change in allele frequencies that occurs after a few individuals establish a new population
Any mechanism that prevents gene flow between populations. Part of speciation
Formation of daughter species from a population or subpopulation of a parent species; the routes vary in their details and duration
A speciation mode by which a physical barrier separates two population and ends the gene flow between them. Then reproductive isolation mechanisms arise
A speciation mode by which new species form within the home range of an existing species, in the absence of a physical barrier
A speciation mode in which different selection pressures lead to divergences within a single population. May occur when one population extends across a broad region encompassing diverse habitats
The process by which close ecological interatctions between two species cause them to evolve jointly
Adaptation of an existing structure for a completely diffferent purpose; a major evolutionary novelty
A structural or functional modification that bestows upon its bearer the opportunity to exploit a habitat more efficiently or in a novel way
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together