Department of Entomology, Zoological State Collection, Munich, Germany.
PLoS One. 2012;7(7):e41377. doi: 10.1371/journal.pone.0041377. Epub 2012 Jul 31.
Between the late Oligocene and the early Miocene, climatic changes have shattered the faunal and floral communities and drove the apparition of new ecological niches. Grassland biomes began to supplant forestlands, thus favouring a large-scale ecosystem turnover. The independent adaptive radiations of several mammal lineages through the evolution of key innovations are classic examples of these changes. However, little is known concerning the evolutionary history of other herbivorous groups in relation with this modified environment. It is especially the case in phytophagous insect communities, which have been rarely studied in this context despite their ecological importance. Here, we investigate the phylogenetic and evolutionary patterns of grass-specialist moths from the species-rich tribe Apameini (Lepidoptera, Noctuidae). The molecular dating analyses carried out over the corresponding phylogenetic framework reveal an origin around 29 million years ago for the Apameini. Ancestral state reconstructions indicate (i) a potential Palaearctic origin of the tribe Apameini associated with a major dispersal event in Afrotropics for the subtribe Sesamiina; (ii) a recent colonization from Palaearctic of the New World and Oriental regions by several independent lineages; and (iii) an ancestral association of the tribe Apameini over grasses (Poaceae). Diversification analyses indicate that diversification rates have not remained constant during the evolution of the group, as underlined by a significant shift in diversification rates during the early Miocene. Interestingly, this age estimate is congruent with the development of grasslands at this time. Rather than clade ages, variations in diversification rates among genera better explain the current differences in species diversity. Our results underpin a potential adaptive radiation of these phytophagous moths with the family Poaceae in relation with the major environmental shifts that have occurred in the Miocene.
在渐新世晚期到中新世早期，气候变化打破了动物群和植物群的生态群落，并催生了新的生态小生境。草原生物群系开始取代林地，从而有利于大规模的生态系统更替。几个哺乳动物谱系通过关键创新的独立适应性辐射是这些变化的典型例子。然而，关于与这种改良环境有关的其他食草类群的进化历史，人们知之甚少。在这种情况下，食草昆虫群落尤其如此，尽管它们具有重要的生态意义，但在这种情况下很少对其进行研究。在这里，我们研究了物种丰富的 Apameini 族（鳞翅目，夜蛾科）草特异性飞蛾的系统发育和进化模式。在相应的系统发育框架上进行的分子定年分析表明，Apameini 大约在 2900 万年前起源。祖先状态重建表明：（i）Apameini 部落可能起源于古北区，并与 Sesamiina 亚部落在热带非洲的一次主要扩散事件有关；（ii）几个独立谱系最近从古北区殖民到新大陆和东洋区；以及（iii）Apameini 部落与禾本科（Poaceae）植物的祖先联系。多样化分析表明，在该组的进化过程中，多样化率并没有保持不变，因为在中新世早期，多样化率发生了显著变化。有趣的是，这个年龄估计与此时草原的发展相一致。不是支系年龄，而是属之间多样化率的变化更好地解释了当前物种多样性的差异。我们的研究结果支持这些食草飞蛾与禾本科植物之间的潜在适应性辐射，与中新世发生的重大环境变化有关。
