Department of Zoology, Stockholm University, Stockholm, 10691, Sweden.
Evolution. 2014 Jan;68(1):105-24. doi: 10.1111/evo.12227. Epub 2013 Aug 29.
It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the "oscillation hypothesis." In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies.
有人认为表型可塑性是生命多样化的主要因素，植食性昆虫的寄主范围变化是研究这一说法的一个很好的模型。我们探讨了被子植物作为幼虫期蝴蝶的寄主，特别是过去寄主范围波动的证据，以及它们与寄主转移和多样化的联系。尽管有 1 亿年的鳞翅目家族历史，但在植物的目水平上，出现了相对简单的寄主利用和寄主转移模式。我们回顾了证据，表明这些寄主转移和伴随的多样化与“波动假说”所建议的短暂的多食性阶段有关。此外，我们调查了所有目前的多食性鳞翅目物种，并证明了多食性状态是罕见的，在系统发育中具有较弱的系统发育信号和非常顶端的分布；我们认为这些都是其短暂性的标志。我们将我们的结果与树皮甲虫 Dendroctonus 的数据进行了对比，在 Dendroctonus 中，更专门的寄主利用是顶端状态。我们的结论是，寄主利用的可塑性可能促成了鳞翅目蝴蝶的多样化。
