Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account

Hardy-Weinberg Equilibrium

1. Large population. The population must be large to minimize random sampling errors.
2.Random mating. There is no mating preference. For example an AA male does not prefer an aa female.
3.No mutation. The alleles must not change.
4.No migration. Exchange of genes between the population and another population must not occur.
5.No natural selection. Natural selection must not favor any particular individual.

Oscillating selection

The situation in which selection alternately favors one phenotype at one time, and a different phenotype at another time, depending on environmental factors.

Frequency-Dependent Selection

An evolutionary process where the fitness of a phenotype is dependent on its frequency relative to other phenotypes in a given population.

Heterozygote Superiority

When individuals who have a heterozygous genotype are more fit than individuals who have a homozygous genotype

Homologous Structures

Homologous structures or organs are those that share a common ancestry or origin.

Vestigial Structures

Vestigial structures are function-less structures that were functioning in an ancestral species.


An individual belonging to a group of organisms having common characteristics and are capable of mating with one another to produce fertile offspring.

Allopatric Speciation

The formation of a new species as a result of an ancestral population's becoming isolated by a geographic barrier.

Sympatric Speciation

The formation of a new species as a result of a genetic change that produces a reproductive barrier between the changed population (mutants) and the parent population. No geographic barrier is present.

Adaptive Radiation

the development of many different forms from an originally homogeneous group of organisms as they fill different ecological niches


the concentration of nerve tissue and sensory organs at the anterior end of an organism


defined and grouped by the possession of one or more shared characteristics (called characters) that are derived from a common ancestor and that were not present in any ancestral group


Derived traits that are shared among a group of organisms and are viewed as evidence of the common ancestry of the group


derived characteristics; structures have undergone recent change; build phylogenies; Ex: Darwin's Finches

Clade Vs. Taxon

Clade: A group of organisms believed to have evolved from a common ancestor, according to the principles of cladistics.

Taxon: A taxonomic category or group, such as a phylum, order, family, genus, or species.

Monophyletic Vs. Polyphyletic

Monophyletic: Developed from a single common ancestral form.

Polyphyletic: Relating to or characterized by development from more than one ancestral type.

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!


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

Voice Recording