Dellicour Simon, Lecocq Thomas, Kuhlmann Michael, Mardulyn Patrick, Michez Denis
Evolutionary Biology and Ecology, Université Libre de Bruxelles, Avenue F.D. Roosevelt 50, 1050 Brussels, Belgium.
Mol Phylogenet Evol. 2014 Jan;70:412-9. doi: 10.1016/j.ympev.2013.08.013. Epub 2013 Aug 28.
New molecular studies suggested that the family Melittidae is either a paraphyletic group from which all the other bees are derived, or the sister clade to all other existing bees. Studying the historical biogeography and evolution of each major lineage within this group is a key step to understand the origin and early radiation of bees. Melitta is the largest genus of melittid bees, for which a robust molecular phylogeny and a biogeographic analysis are still lacking. Here, we derive a phylogenetic hypothesis from the sequences of seven independent DNA fragments of mitochondrial and nuclear origin. This phylogenetic hypothesis is then used to infer the evolution of the species range and of the host-plant shifts in Melitta. Our results confirmed the monophyly of Melitta, but did not recover all previously defined clades within the genus. We propose new taxa by splitting the genus in three subgenera (including two new subgenera described in the Appendix: Afromelitta subgen. nov., Plesiomelitta subgen. nov.) and describe two new species: Melitta avontuurensis sp. n. and M. richtersveldensis sp. n. Regarding the evolution of host-plant use, our analysis suggests that all species currently specialized on one plant family originated from an ancestor that was specialized on Fabaceae plants. The inferred biogeographic history for the genus supported an African origin. In concordance with previous studies identifying Africa as the geographic origin for many clades of bees, our data bring new evidence for an African origin of melittid bees.
新的分子研究表明，准蜂科要么是一个并系类群，所有其他蜜蜂都由其演化而来，要么是所有现存其他蜜蜂的姐妹进化枝。研究该类群中每个主要谱系的历史生物地理学和进化是理解蜜蜂起源和早期辐射的关键一步。准蜂属是准蜂科蜜蜂中最大的属，目前仍缺乏一个可靠的分子系统发育和生物地理学分析。在这里，我们从线粒体和核起源的七个独立DNA片段序列推导出一个系统发育假说。然后，这个系统发育假说被用来推断准蜂属物种分布范围的演变以及寄主植物的转变。我们的结果证实了准蜂属的单系性，但未恢复该属内所有先前定义的进化枝。我们通过将该属划分为三个亚属（包括附录中描述的两个新亚属：新非洲准蜂亚属、新近准蜂亚属）提出了新的分类单元，并描述了两个新物种：阿冯图尔准蜂和里氏准蜂。关于寄主植物利用的进化，我们的分析表明，目前所有专化于一个植物科的物种都起源于一个专化于豆科植物的祖先。该属推断的生物地理历史支持其起源于非洲。与之前将非洲确定为许多蜜蜂进化枝地理起源的研究一致，我们的数据为准蜂科蜜蜂起源于非洲提供了新证据。
