The term phylogeography was first used by
John Avise in his 1987 work
Intraspecific Phylogeography: The Mitochondrial DNA Bridge Between Population Genetics and Systematics. Historical biogeography is a synthetic discipline that addresses how historical, geological, climatic and ecological conditions influenced the past and current distribution of species. As part of historical biogeography, researchers had been evaluating the geographical and evolutionary relationships of organisms years before. Two developments during the 1960s and 1970s were particularly important in laying the groundwork for modern phylogeography; the first was the spread of
cladistic thought, and the second was the development of
plate tectonics theory. The resulting school of thought was vicariance biogeography, which explained the origin of new lineages through geological events like the drifting apart of continents or the formation of rivers. When a continuous population (or species) is divided by a new river or a new mountain range (i.e., a vicariance event), two populations (or species) are created.
Paleogeography,
geology and
paleoecology are all important fields that supply information that is integrated into phylogeographic analyses. Phylogeography takes a
population genetics and
phylogenetic perspective on
biogeography. In the mid-1970s, population genetic analyses turned to mitochondrial markers. The advent of the
polymerase chain reaction (PCR), the process where millions of copies of a
DNA segment can be replicated, was crucial in the development of phylogeography. Thanks to this breakthrough, the information contained in mitochondrial DNA sequences was much more accessible. Advances in both laboratory methods (e.g.
capillary DNA sequencing technology) that allowed easier sequencing of DNA and computational methods that make better use of the data (e.g. employing
coalescent theory) have helped improve phylogeographic inference.
Example Climate change, such as the glaciation cycles of the past 2.4 million years, has periodically restricted some species into disjunct refugia. These restricted ranges may result in
population bottlenecks that reduce genetic variation. Once a reversal in climate change allows for rapid migration out of refugial areas, these species spread rapidly into newly available habitat. A number of empirical studies find genetic signatures of both animal and plant species that support this scenario of refugia and postglacial expansion. as well as temperate regions that were directly influenced by glaciers. ==In conservation==