Laurasian migration explains Gondwanan disjunctions: evidence from Malpighiaceae.
Explanations for biogeographic disjunctions involving South America and Africa typically invoke vicariance of western Gondwanan biotas or long distance dispersal. These hypotheses are problematical because many groups originated and diversified well after the last known connection between Africa and South America (approximately 105 million years ago), and it is unlikely that "sweepstakes" dispersal accounts for many of these disjunctions. Phylogenetic analyses of the angiosperm clade Malpighiaceae, combined with fossil evidence and molecular divergence-time estimates, suggest an alternative hypothesis to account for such distributions. We propose that Malpighiaceae originated in northern South America, and that members of several clades repeatedly migrated into North America and subsequently moved via North Atlantic land connections into the Old World during episodes starting in the Eocene, when climates supported tropical forests. This Laurasian migration route may explain many other extant lineages that exhibit western Gondwanan distributions.
Davis
Charles C
CC
Department of Organismic and Evolutionary Biology, Harvard University Herbaria, 22 Divinity Avenue, Cambridge, MA 02138, USA. cdavis@oeb.harvard.edu
Bell
Charles D
CD
Mathews
Sarah
S
Donoghue
Michael J
MJ
D029681:Arabidopsis Proteins; D001483:Base Sequence; D018744:DNA, Plant; D019143:Evolution, Molecular; D029581:Malpighiaceae / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D009245:NADH Dehydrogenase / Q000235:genetics*; D009656:North America; D010802:Phylogeny; D010834:Phytochrome / Q000235:genetics*; D010940:Plant Proteins; D013020:South America
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D010940:Plant Proteins; C406683:phytochrome C, Arabidopsis; D010834:Phytochrome; C489904:NdhF protein, plant; D009245:NADH Dehydrogenase