Geodispersal
Encyclopedia
In biogeography
, geodispersal is the erosion of barriers to gene flow and biological dispersal
(Lieberman, 2005.; Albert and Crampton, 2010.). Geodispersal differs from vicariance
as a means of explaining the patterns of distribution among related species. In geodispersal, the geographical ranges of individual taxa, or of whole biotas
, are merged by erosion of a physical barrier to gene flow or dispersal
. A well documented example of geodispersal in between continental ecosystems was the Great American Biotic Interchange (GABI) between the terrestrial faunas and floras of North America
and South America
, that followed the formation of the Isthmus of Panama
about 3 million years ago. Another well documented example of geodispersal was the formation of the modern Amazon
River Basin about 10 million years ago, which involved the merging of previously isolated Neotropical fish
faunas to form what is now the most species-rich continental aquatic ecosystem
on Earth (Oberdorff et al., 2011).
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
, geodispersal is the erosion of barriers to gene flow and biological dispersal
Biological dispersal
Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...
(Lieberman, 2005.; Albert and Crampton, 2010.). Geodispersal differs from vicariance
Vicariance
Vicariance is a process by which the geographical range of an individual taxon, or a whole biota, is split into discontinuous parts by the formation of a physical barrier to gene flow or dispersal. Vicariance of whole biotas occurs following large-scale geophysical events such as the uplift of a...
as a means of explaining the patterns of distribution among related species. In geodispersal, the geographical ranges of individual taxa, or of whole biotas
Biota (ecology)
Biota are the total collection of organisms of a geographic region or a time period, from local geographic scales and instantaneous temporal scales all the way up to whole-planet and whole-timescale spatiotemporal scales. The biota of the Earth lives in the biosphere.-See...
, are merged by erosion of a physical barrier to gene flow or dispersal
Biological dispersal
Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...
. A well documented example of geodispersal in between continental ecosystems was the Great American Biotic Interchange (GABI) between the terrestrial faunas and floras of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, that followed the formation of the Isthmus of Panama
Isthmus of Panama
The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country of Panama and the Panama Canal...
about 3 million years ago. Another well documented example of geodispersal was the formation of the modern Amazon
Amazon Basin
The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...
River Basin about 10 million years ago, which involved the merging of previously isolated Neotropical fish
Neotropical fishes
The freshwater fishes of tropical South and Central America represent one of the most diverse aquatic ecosystems on Earth, with more than 5,600 species, representing about 10% all living vertebrate species...
faunas to form what is now the most species-rich continental aquatic ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
on Earth (Oberdorff et al., 2011).