What is a Vicariant event?

A process in which two or more populations of the same (but geographically separated and non-interbreeding) species become less similar to each other over time, through mutation or survival advantages of different traits in differing environments, and eventually become distinct species.

What is an example of a vicariance event?

One way this happens is by “vicariance,” geographical change that can be slow or rapid. An example of vicariance is the separation of marine creatures on either side of Central America when the Isthmus of Panama closed about 3 million years ago, creating a land bridge between North and South America.

What is vicariance in ecology?

Vicariance is the emergence of geographic barriers to dispersal and gene flow, which spatially isolates populations and may lead to the formation of new species (i.e., allopatric speciation; Figure 2).

What causes vicariance?

It is based on two major tectonic events that created belated links between Gondwana and Laurasia, namely the detachment of India and then Australia from Gondwana in the Early Cretaceous followed by the collision (India) and closing-up (Australia) of these continental masses with Asia in the Cenozoic.

What is parapatric speciation and give an example?

The best-known example of incipient parapatric speciation occurs in populations of the grass Agrostis tenuis which span mine tailings and normal soils. Individuals that are tolerant to heavy metals, a heritable trait, survive well on contaminated soil, but poorly on non-contaminated soil.

What does vicariant mean in biology?

: of, relating to, or being the process of vicariance or organisms that evolved through this process the possible vicariant origin of the Antillean arthropod fauna.

What is an example of a vicariant event?

For example, if two widespread species were fragmented by a vicariant event, one would eventually expect that haplotypes in each species would be monophyletic on each side of the isolating barrier. An ancestral vicariant event in the Pacific must have caused early divergence of these two clades.

What are the effects of vicariant events on gene flow?

Consider now effects of a vicariant event that interrupts gene flow at one point in the cline, but that leaves all populations on either side of this point still exchanging migrants.

What is an example of broad vicariant distribution?

A well-known example of a broad vicariant pattern of distribution is found in the plant genus Nothofagus (Nothofagaceae) in the Southern Hemisphere, with species distributed in South America, New Guinea, Australia, New Caledonia, and New Zealand and fossils known from Antarctica.