Department of Biological Sciences, University of Idaho, Moscow, ID 83844-3051, USA.
Evolution. 2011 Apr;65(4):946-60. doi: 10.1111/j.1558-5646.2010.01190.x. Epub 2010 Dec 13.
Understanding the factors that promote or inhibit species formation remains a central focus in evolutionary biology. It has been difficult to make generalities about the process of ecological speciation in particular given that each example is somewhat idiosyncratic. Here we use a case study of replicated ecological speciation in the same selective environment to assess factors that account for similarities and differences across taxa in progress towards ecological speciation. We study three different species of lizards on the gypsum sand dunes of White Sands, New Mexico, and present evidence that all three fulfill the essential factors for ecological speciation. We use multilocus nuclear data to show that progress toward ecological speciation is unequal across the three species. We also use morphometric data to show that traits other than color are likely under selection and that selection at White Sands is both strong and multifarious. Finally, we implicate geographic context to explain difference in progress toward speciation in the three species. We suggest that evaluating cases from the natural world that are "same same but different" can reveal the mechanisms of ecological speciation.
理解促进或抑制物种形成的因素仍然是进化生物学的核心关注点。特别是，由于每个例子都有些特殊，因此很难对生态物种形成的过程进行概括。在这里，我们使用在相同选择环境中重复出现的生态物种形成的案例研究来评估在朝着生态物种形成的过程中，哪些因素可以解释分类群之间的相似性和差异性。我们研究了新墨西哥州白沙的石膏沙丘上的三种不同蜥蜴物种，并提供了证据表明，所有三种物种都满足生态物种形成的基本因素。我们使用多位点核数据表明，在这三个物种中，朝着生态物种形成的进展是不平等的。我们还使用形态计量学数据表明，除颜色以外的特征可能受到选择的影响，并且白沙的选择既强大又多样化。最后，我们将地理背景纳入解释三个物种在物种形成进展方面的差异。我们认为，评估来自“大同小异”的自然世界的案例可以揭示生态物种形成的机制。
