Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Graduate Program in Organismic & Evolutionary Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Science. 2024 Oct 11;386(6718):211-217. doi: 10.1126/science.adj4478. Epub 2024 Oct 10.
The theory of ecological speciation posits that adaptive divergence among incipient species raises incidental barriers to reproduction, thus catalyzing the emergence of new species. In this study, we conducted an experimental test of this theory in Galápagos finches, a clade in which beaks and mating songs are mechanistically linked. We forecasted the acoustic structure of songs for a set of possible evolutionary futures (successive droughts spurring increasingly large beaks) and, in a field assay, presented resulting song simulations to territorial males. We found that responses to songs dropped off after six simulated drought events, to degrees roughly comparable to drops in response to songs that diverged through cultural drift and acoustic adaptation. Our results support, in Darwin's finches, the feasibility and mechanistic bases of an ecological speciation hypothesis.
生态物种形成理论认为，初生物种之间的适应性分歧会产生偶然的生殖障碍，从而促进新物种的出现。在这项研究中，我们在加拉帕戈斯雀类中对这一理论进行了实验测试，雀类的鸟喙和交配歌曲在机制上是相关联的。我们预测了一系列可能的进化未来（连续干旱刺激喙越来越大）中歌曲的声学结构，并在野外试验中向领地雄性展示了由此产生的歌曲模拟。我们发现，对歌曲的反应在六个模拟干旱事件后下降，下降程度与对通过文化漂移和声学适应而产生差异的歌曲的反应下降程度大致相当。我们的研究结果支持在达尔文雀中，生态物种形成假说的可行性和机械基础。
