Molecular biogeography in 2005: back to the future

Abstract

The cosmologist Stephen Hawking hasdubbed the twenty-first century the centuryof complexity. Biogeography has experienceda significant growth spurt in the past yearincorporating evolutionary complexity to adegree previously only imagined. Most of thisgrowth has been in the area of historical bio-geography, that is, studies encompassing thegeographic context of evolution. The princi-ples and theories, and methods of analysis,were not developed by molecular biologistsand are not constrained to molecular biology.Molecular data, however, add an essentialempirical dimension to this fascinating area ofresearch.As in previous recent years, the greatestnumber of publications and the greatestamount of effort by molecular biologists inbiogeography has been in the area called phy-logeography (see review by Riddle andHafner, 2004). Riddle (2005) discussed threeareas of research that are of especial interestto phylogeographers at the moment. The firstof these involves the ongoing controversyover the utility of mitochondrial DNA(mtDNA) in evolutionary studies. A growingnumber of systematists question the utility ofmtDNA for phylogeny reconstruction. Boththe high rate of evolutionary turnover andmaternal-only pattern of inheritance mayproduce incongruence between mtDNAgene trees and species phylogenies; for an excellent discussion, see Taggart