vicariance

American  

[vahy-kair-ee-uhns, vi-] / vaɪˈkɛər i əns, vɪ- /

noun

Biology.

1. the geographical separation and isolation of a subpopulation, resulting in the original population's differentiation as a new variety or species.

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vicariance Scientific  

/ vī-kâr′ē-əns,vĭ- /

1. The separation or division of a group of organisms by a geographic barrier, such as a mountain or a body of water, resulting in differentiation of the original group into new varieties or species.

2. See also speciation

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Other Word Forms

• vicariant adjective

Etymology

Origin of vicariance

First recorded in 1955–60; from Latin vicāri(us) “substituting” + -ance ( def. )

Example Sentences

Their scattered distribution across South America, Australia, South Africa, and New Zealand is a classic case of vicariance -- a process in which natural barriers such as mountains or rivers divide a population, forcing each group to evolve independently and form new species.

From Science Daily

However, others have argued that much of Sulawesi’s flora and fauna originated more recently, and not through vicariance, but through over-water dispersal of species from Asia and Australia in the last 15m years.

From The Guardian

They also may represent early inklings of the dispersal-vicariance debate: the stepping-stone and cargo ideas are obviously about long-distance dispersal, and the notion of Atlantis as a land bridge looks like a vicariance hypothesis, with the continuous ranges of animal “kinds” being split into Old and New World portions by the drowning of the lost continent.

From Salon

Dr John Sparks, a co-author from the American Museum of Natural History explained: "The sister-group relationship between obligate cave fish from Madagascar and Australia is a remarkable example of Gondwanan vicariance - a split dating back to the Late Cretaceous."

From BBC

For a family with five species, as illustrated, the probability that a lineage survives to the present in both regions, creating a coalescence point at the time of the vicariance event, is 0.14 for λ = 5 and 0.04 for λ = 10.

From Science Magazine