Department of Entomology, University of California-Davis, Davis, CA 95616, USA.
Mol Phylogenet Evol. 2012 Nov;65(2):421-36. doi: 10.1016/j.ympev.2012.06.028. Epub 2012 Jul 10.
This study unravels the evolution and biogeographic history of the globally distributed ant genus Crematogaster on the basis of a molecular phylogeny, reconstructed from five nuclear protein-coding genes and a total of 3384 bp of sequence data. A particular emphasis is placed on the evolutionary history of these ants in the Malagasy region. Bayesian and likelihood analyses performed on a dataset of 124 Crematogaster ingroup taxa lend strong support for three deeply diverging phylogenetic lineages within the genus: the Orthocrema clade, the Global Crematogaster clade and the Australo-Asian Crematogaster clade. The 15 previous subgenera within Crematogaster are mostly not monophyletic. Divergence dating analyses and ancestral range reconstructions suggest that Crematogaster evolved in South-East Asia in the mid-Eocene (40-45 ma). The three major lineages also originated in this region in the late Oligocene/early Miocene (~24-30 ma). A first dispersal out of S-E Asia by an Orthocrema lineage is supported for 22-30 ma to the Afrotropical region. Successive dispersal events out of S-E Asia began in the early, and continued throughout the late Miocene. The global distribution of Crematogaster was achieved by subsequent colonizations of all major biogeographic regions by the Orthocrema and the Global Crematogaster clade. Molecular dating estimates and ancestral range evolution are discussed in the light of palaeogeographic changes in the S-E Asian region and an evolving ocean circulation system throughout the Eocene, Oligocene and Miocene. Eight dispersal events to/from Madagascar by Crematogaster are supported, with most events occurring in the late Miocene to Pliocene (5.0-9.5 ma). These results suggest that Crematogaster ants possess exceptional dispersal and colonization abilities, and emphasize the need for detailed investigations of traits that have contributed to the global evolutionary success of these ants.
本研究基于分子系统发育重建，利用五个核蛋白编码基因和 3384 个碱基对的序列数据，揭示了全球分布的蚂蚁属 Crematogaster 的进化和生物地理历史。特别强调了这些蚂蚁在马达加斯加地区的进化历史。对 124 个 Crematogaster 内群分类群数据集进行的贝叶斯和似然分析强烈支持该属内三个深度分化的系统发育谱系：Orthocrema 分支、全球 Crematogaster 分支和澳亚 Crematogaster 分支。Crematogaster 中的 15 个先前亚属大多不是单系的。分化时间分析和祖先范围重建表明，Crematogaster 起源于中新世中期（40-45 百万年前）的东南亚。这三个主要谱系也起源于上新世/早更新世晚期（约 24-30 百万年前）的该地区。一个 Orthocrema 谱系从东南亚向外首次扩散的时间支持在 22-30 百万年前到达热带非洲地区。从东南亚向外的连续扩散事件始于早更新世，并持续到晚更新世。Crematogaster 的全球分布是通过 Orthocrema 和全球 Crematogaster 分支随后在所有主要生物地理区域的殖民化实现的。分子年代估计和祖先范围进化是在东南亚地区古地理变化和整个始新世、渐新世和中新世期间海洋环流系统不断演变的背景下讨论的。支持 Crematogaster 向/从马达加斯加进行了八次扩散事件，其中大多数事件发生在晚更新世到上新世（5.0-9.5 百万年前）。这些结果表明，Crematogaster 蚂蚁具有非凡的扩散和殖民能力，并强调需要详细研究有助于这些蚂蚁全球进化成功的特征。
