Proposed Amazonian Refugia from Haffer, 1969

In the most basic biological sense refugia (singular: refugium) refer to locations of isolated or relict populations of once widespread animal or plant species. This isolation (allopatry) can be the result of human activities - such as deforestation, over hunting, etc. - or climatic changes. Present examples of such refuge species may be the mountain gorilla, now isolated to specific mountains in central Africa, and the Australian Sea Lion, presently isolated to specific breeding beaches in south 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 many endemic species, not found elsewhere, which survive as relict populations. Allopatric speciation (also known as Allopatry) is speciation by geographical isolation. ... Deforestation is the conversion of forested areas to non-forest land use such as arable land, urban use, logged area or wasteland. ... Trinomial name Gorilla berengei berengei Matschie, 1914 The Mountain Gorilla (Gorilla beringei beringei) is one of two subspecies of Eastern Gorillas. ... Binomial name Neophoca cinerea Peron, 1816 The Australian Sea Lion (Neophoca cinerea) is a species of sea lion that breeds only on the south coast of Australia. ... Emblems: Hairy Nosed Wombat (faunal); Leafy Seadragon (marine); Piping Shrike (bird: unofficial); Sturts Desert Pea (floral); Opal (gemstone) Motto: United for the Common Wealth Slogan or Nickname: Festival State Other Australian states and territories Capital Adelaide Government Const. ... This article is about the ecological meaning of endemic. See also endemic (epidemiology). ...

More specifically, however, Jurgen Haffer first proposed the concept of refugia to help explain the biological diversity of bird populations in the Amazonian river basin. Haffer forwarded that climatic change in the late Pleistocene led to reduced reservoirs of habitable forests in which populations become allopatric. Over time the various species in these refugia evolved differently from their counterpart species in different refugia. As the Pleistocene came to an end, the more arid conditions gave way to the present humid rainforest environment, reconnecting the refugia. However, the period of isolation was sufficient to cause speciation events, turning these once unified species into parapatric sister species. Biodiversity or biological diversity is a neologism and a portmanteau word, from bio and diversity. ... The Pleistocene epoch (IPA: ) is part of the geologic timescale. ... Charles Darwins first sketch of an evolutionary tree from his First Notebook on Transmutation of Species (1837) Speciation is the theory of the evolutionary process by which new biological species are believed by some to arise. ...

This mode of speciation has since been expanded, being used to explain population patterns in other areas of the world, such as Africa and North America. Theoretically, current biogeographical patterns can be used to infer past refugia: where several unrelated species follow concurrent range patterns, it may be the case that that area was once a refugium. Speciation by this model is still highly controversial, however. A world map showing the continent of Africa. ... World map showing North America A satellite composite image of North America. ... Charles Darwins first sketch of an evolutionary tree from his First Notebook on Transmutation of Species (1837) Speciation is the theory of the evolutionary process by which new biological species are believed by some to arise. ...

See also:

• Biogeography
• Population biology
• Population genetics

Biogeography is the science which deals with patterns of species distribution and the processes that result in such patterns. ... Population biology is a study of biological populations of organisms, especially in terms of biodiversity, evolution, and environmental biology. ... Population genetics is the study of the distribution of and change in allele frequencies under the influence of the four evolutionary forces: natural selection, genetic drift, mutation, and migration. ...

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.