Janz Niklas, Braga Mariana P, Wahlberg Niklas, Nylin Sören
Department of Zoology, Stockholm University, 106 91, Stockholm, Sweden.
Laboratory of Genetics, Department of Biology, University of Turku, 20014, Turku, Finland.
Evolution. 2016 May;70(5):1150-5. doi: 10.1111/evo.12927. Epub 2016 May 5.
The diversification of plant-feeding insects is seen as a spectacular example of evolutionary radiation. Hence, developing hypotheses to explain this diversification, and methods to test them, is an important undertaking. Some years ago, we presented the oscillation hypothesis as a general process that could drive diversification of this and similar interactions, through repeated expansions and contractions of host ranges. Hamm and Fordyce recently presented a study with the outspoken intention of testing this hypothesis where they concluded that the oscillation hypothesis was not supported. We point out several problems with their study, owing both to a misrepresentation of our hypothesis and to the methods. We provide a clarifying description of the oscillation hypothesis, and detail some predictions that follow from it. A reanalysis of the data demonstrated a troubling sensitivity of the "SSE" class of models to small changes in model specification, and we caution against using them for tests of trait-based diversification. Future tests of the hypothesis also need to better acknowledge the processes behind the host range oscillations. We suspect that doing so will resolve some of the apparent conflicts between our hypothesis and the view presented by Hamm and Fordyce.
植食性昆虫的多样化被视为进化辐射的一个显著例子。因此，提出解释这种多样化的假说并开发检验这些假说的方法是一项重要任务。几年前，我们提出了振荡假说，认为这是一个通过宿主范围的反复扩张和收缩来推动此类及类似相互作用多样化的一般过程。哈姆和福代斯最近发表了一项研究，其明确目的是检验这一假说，他们得出的结论是振荡假说不成立。我们指出了他们研究中的几个问题，这既有对我们假说的错误表述，也有方法上的问题。我们对振荡假说进行了清晰的描述，并详细说明了由此得出的一些预测。对数据的重新分析表明，“SSE”类模型对模型设定的微小变化具有令人不安的敏感性，我们提醒不要将它们用于基于性状的多样化检验。对该假说的未来检验还需要更好地认识宿主范围振荡背后的过程。我们怀疑这样做将解决我们的假说与哈姆和福代斯所提出观点之间的一些明显冲突。
