- Refugium (population biology)
In biology a refugium (plural: refugia) is a location of an isolated or
relict population of a once widespread animal or plant species.This isolation (
allopatry ) can be due to climatic changes or human activities such asdeforestation and over-hunting. Present examples of refuge species are themountain gorilla , isolated to specific mountains in central Africa, and theAustralian Sea Lion , isolated to specific breeding beaches inSouth Australia due to over hunting. This isolation, in many cases, can be seen as only a temporary state; however, some refugia may be long-standing, thereby having manyendemic species , not found elsewhere, which survive asrelict population s.Some ancestral human populations may have been forced back to similar small isolated pockets in the face of the continental
ice sheet s during the last ice age. Suggested examples include theBering land bridge ,Ukrainian LGM refuge and theIberian , Italian, andBalkan peninsulas.Speciation
Jürgen Haffer first proposed the concept of refugia to explain thebiological diversity of bird populations in theAmazonian river basin . Haffer suggested that climatic change in the latePleistocene led to reduced reservoirs of habitable forests in which populations become allopatric. Over time, this led tospeciation , that is, populations of the same species different refugia evolved differently, creatingparapatric sister species . As the Pleistocene ended, the arid conditions gave way to the present humid rainforest environment, reconnecting the refugia.This mode of speciation has since been expanded and been used to explain population patterns in other areas of the world, such as
Africa andNorth America . Theoretically, current biogeographical patterns can be used to infer past refugia: where several unrelated species follow concurrent range patterns, the area may have been a refugium. But this model ofspeciation is still highly controversial.Drug resistance refugia
Refugia is the proportion of the population that is not selected by drug treatment.
-"In refuge" from drug
It provides a pool of suspectible genes. It dilutes resistant genes in the population. Until recently, overlooked as the most important component of drug resistance selection.
ee also
*
Biogeography
*Population biology
*Population genetics
*Fisheries "Refugia" [http://refugia.unepscs.org]References
* Coyne, Jerry A. & Orr, H. Allen. 2004. "Speciation". Sunderland: Sinauer Associates, Inc. ISBN 0-87893-091-4
* Haffer, Jurgen. 1969. Speciation in Amazonian Forest Birds. "Science". Vol. 165:131-137.
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