Editing Biogeography (section)

==Paleobiogeography==
{{See also|Dinosaur paleobiogeography}}
[[File:Wegener fossils-mapped.png|thumb|300px|Distribution of four Permian and Triassic fossil groups used as biogeographic evidence for continental drift, and land bridging]]
Paleobiogeography goes one step further to include [[paleogeography|paleogeographic]] data and considerations of [[plate tectonics]]. Using molecular analyses and corroborated by [[fossils]], it has been possible to demonstrate that [[perching birds]] evolved first in the region of [[Australia]] or the adjacent [[Antarctic]] (which at that time lay somewhat further north and had a temperate climate). From there, they spread to the other [[Gondwana]]n continents and Southeast Asia&nbsp;– the part of [[Laurasia]] then closest to their origin of dispersal&nbsp;– in the late [[Paleogene]], before achieving a global distribution in the early [[Neogene]].<ref>{{cite journal|last1=Jønsson|first1=Knud A|last2=Fjeldså|first2=Jon|year=2006|title=Determining biogeographical patterns of dispersal and diversification in oscine passerine birds in Australia, Southeast Asia and Africa|journal=[[Journal of Biogeography]]|volume=33|issue=7|pages=1155–1165|doi=10.1111/j.1365-2699.2006.01507.x}}</ref> Not knowing that at the time of dispersal, the Indian Ocean was much narrower than it is today, and that South America was closer to the Antarctic, one would be hard pressed to explain the presence of many "ancient" lineages of perching birds in Africa, as well as the mainly South American distribution of the [[suboscine]]s.{{cn|date=June 2024}}

Paleobiogeography also helps constrain hypotheses on the timing of biogeographic events such as [[vicariance]] and [[geodispersal]], and provides unique information on the formation of regional biotas. For example, data from species-level phylogenetic and biogeographic studies tell us that the [[Amazon Basin|Amazonian]] [[teleost]] fauna accumulated in increments over a period of tens of millions of years, principally by means of allopatric speciation, and in an arena extending over most of the area of tropical South America.<ref>* {{cite book|last1=Albert|first1=JS|first2=RE|last2=Reis|year=2011|url=http://www.ucpress.edu/book.php?isbn=9780520268685|title=Historical Biogeography of Neotropical Freshwater Fishes|publisher=University of California Press|location=Berkeley}}</ref> In other words, unlike some of the well-known insular faunas ([[Galapagos finches]], Hawaiian drosophilid flies, African rift lake [[cichlids]]), the species-rich Amazonian ichthyofauna is not the result of recent [[adaptive radiation]]s.<ref name="Lovejoy, N. R. 2010 Pp. 405-417">{{cite book|last1=Lovejoy|first1=NR|first2=SC|last2=Willis|first3=JS|last3=Albert|year=2010|chapter=Molecular signatures of [[Neogene]] biogeographic events in the Amazon fish fauna|pages=405–417|title=Amazonia, Landscape and Species Evolution|edition=1st|editor1-last=Hoorn|editor1-first=CM|editor2-last=Wesselingh|editor2-first=FP|location=London|publisher=Blackwell Publishing}}</ref>

For [[freshwater]] organisms, landscapes are divided naturally into discrete [[drainage basin]]s by [[Drainage divide|watersheds]], episodically isolated and reunited by [[erosion]]al processes. In regions like the [[Amazon Basin]] (or more generally Greater Amazonia, the Amazon basin, [[Orinoco]] basin, and [[Guianas]]) with an exceptionally low (flat) topographic relief, the many waterways have had a highly reticulated history over [[geological time]]. In such a context, [[stream capture]] is an important factor affecting the evolution and distribution of freshwater organisms. Stream capture occurs when an upstream portion of one river drainage is diverted to the downstream portion of an adjacent basin. This can happen as a result of [[tectonic uplift]] (or [[subsidence]]), natural damming created by a [[landslide]], or headward or lateral [[erosion]] of the watershed between adjacent basins.<ref name="Lovejoy, N. R. 2010 Pp. 405-417"/>