Chapter 10: Species and Speciation

A summary of key terms and concepts related to species and speciation in the context of evolution and biological diversity.

Allopatric speciation

Speciation driven by geographic isolation.

Assortative mating

The phenomenon in which individual organisms tend to mate with other organisms with trait values similar to theirs.

Biological Species Concept

The view that species are defined by their ability to reproduce with one another and to be unable to reproduce with the members of other species.

Clinal variation

Gradual changes in traits as a function of geographical separation.

Discrete variation

Genetic variation among geographically separated populations, where each population contains genetically similar individuals.

Extrinsic reproductive isolation

The phenomenon in which two organisms are unable to reproduce due to geographic separation.

Intrinsic reproductive isolation

The phenomenon in which two organisms are no longer able to reproduce, even when they are allowed to encounter one another.

Phylogenetic Species Concept

The view that species are clades (monophyletic groups), assigned to the species rank for practical reasons.

Speciation

The splitting of an ancestral species into descendant species.

Sympatric speciation

Speciation without geographical separation, driven by assortative mating within a population.