China Weekly News
2010 APR 20 - According to recent research published in the Journal of Biogeography, "This study addresses the origins of terrestrial biodiversity of the Fijian islands using the ant genus Lordomyrma (Hymenoptera: Formicidae: Myrmicinae) as a model system. We derive the evolution of the genus and determine its closest extra-Fijian relatives from geological data, molecular phylogenetic reconstruction and divergence estimates."
"Location Ant taxa were sampled in the Southwest Pacific, Melanesia, Southeast Asia, Australia and mainland China. Phylogeny and divergence estimates of the ant genus Lordomyrma based on four nuclear genes (28S, ArgK, LW Rh, CAD) plus data on Indo-Pacific geological history are used to address current hypotheses regarding the origins of the Fijian biota. The genus Lordomyrma probably originated in mainland Asia, with subsequent colonization of Australia and the Pacific. The Fijian Lordomyrma clade is monophyletic, and originated c. 8.8 Ma, when it diverged from a sister group in Papua New Guinea.
Main conclusions The colonization of Fiji by Lordomyrma is probably a result of long-distance dispersal from New Guinea, possibly aided by island hopping across the Vitiaz Arc. The timeline of diversification in Lordomyrma is broadly congruent with the Miocene fragmentation of the Vitiaz Arc and the Pliocene emergence of Vanua Levu. The biotic shuttle hypothesis, which posits 'Eua Island as the source of Fijian endemics, is rejected based on the sister relationship of Fiji and New Guinea lineages, as well as on the Miocene submergence of the terrane below sea level. The diversity of Fijian Lordomyrma results from the radiation of a single lineage, which diverged from a New Guinea sister group," wrote A. Lucky and colleagues, University of California.
The researchers concluded: "The genus appears to have originated in Asia rather than in Australia."
This article was prepared by China Weekly News editors from staff and other reports.
