What is vicariance in evolution?
: fragmentation of the environment (as by splitting of a tectonic plate) in contrast to dispersal as a factor in promoting biological evolution by division of large populations into isolated subpopulations.
Why is vicariance important?
Vicariance and geodispersal are complimentary biogeographic processes that have profoundly influenced the formation of new species and the taxonomic composition of regional biotas. Together these processes interact in a complex duet of Earth history events and biological diversification.
What is vicariance and dispersal?
Biologists group allopatric processes into two categories: dispersal and vicariance. Dispersal occurs when a few members of a species move to a new geographical area, while vicariance occurs when a natural situation arises to physically divide organisms.
What is vicariance model?
Vicariance is a process by which the geographical range of an individual taxon, or a whole biota, is split into discontinuous populations (disjunct distributions) by the formation of an extrinsic barrier to the exchange of genes: that is, a barrier arising externally to a species.
What is a vicariance event?
A vicariance event was defined as the splitting of an ancestral widespread lineage into two daughter lineages that were divided between two adjacent regions. A dispersal, extinction, cladogenesis (DEC) model was used to reconstruct ancestral patterns of vicariance among the five designated regions.
What is vicariance quizlet?
Define vicariance: the geographical separation of a population, typically by a physical barrier such as a mountain range or river, resulting in a pair of closely related species.
Is there a relation between dispersal and vicariance?
Relatively few empirical studies, especially those employing molecular phylogenies that allow a temporal perspective, have attempted to estimate the relative roles of dispersal and vicariance. In this study, the frequencies of vicariance and dispersal were estimated in six lineages of birds that occur mostly in the aridlands of North America.
What is vicariance in geography?
A process in which a species’ range is divided even though the species has remained in place. This might happen through tectonic action, geologic activity (like the rise of a mountain range or shift in the course of a river), or other processes. Vicariance is usually contrasted with dispersal as a biogeographic mechanism.
Why is the process of vicariance a reasonable starting hypothesis?
The process of vicariance is the reasonable starting hypothesis for all biogeographical analyses explaining a disjointed distribution because it involves the least amount of assumptions.
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.