Amborella trichopoda Baill. (Amborellaceae, Amborellales), the sole living member of the sister group to all other extant Angiosperms, is endemic to New Caledonia. We addressed the intraspecific phylogeography of Amborella by investigating whether its present population genetic structure could be related to its current and past habitats. We found moderate range-wide genetic diversity based on nuclear microsatellite data, and detected four well-differentiated, geographically distinct genetic groups using Bayesian clustering analyses. We modeled the ecological niche...