FOSSIL CROSS-VALIDATION OF THE DATED ANT PHYLOGENY (HYMENOPTERA - FORMICIDAE)

摘要

As molecular clock methods become more widely used it has become apparent that careful consideration of fossil minimum calibrations is essential. Not only is it necessary tobe certain of the taxonomic identity of the fossils and correct placement within the phylogenetic tree, recent studies have suggested that when multiple fossils are available consideration of conflict among fossils must also be taken into account. In this study we investigate whether any of the 43 fossils used by Moreau, et al. (2006) are "inconsistent" and how this affects the results of molecular clock dating analyses and inferred diversification patterns. After considering each of the 43 fossils in turn, followingthe methods of Near and colleagues (Near & Sanderson, 2004; Near et al., 2005), we found that five fossils are considered to be "inconsistent." After removing these fossils and reanalyzing the data, we found that excluding these minimum age fossil calibration points did not have a considerable effect on the results. Comparing lineages-through-time plots demonstrate that not only are similar ages recovered, but also that the previously inferred significant shift in diversification rates within the ant phylogeny is not an artifact of the "inconsistent" fossils. These findings suggest that all available fossil information should be included in molecular clock analyses.