Biology Department, Amphibian Evolution Lab, Unit of Ecology and Systematics, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
Science. 2010 Feb 5;327(5966):679-82. doi: 10.1126/science.1181707.
Recent studies have identified range expansion as a potential driver of speciation. Yet it remains poorly understood how, under identical extrinsic settings, differential tendencies for geographic movement of taxa originate and subsequently affect diversification. We identified multiple traits that predict large distributional ranges in extant species of toads (Bufonidae) and used statistical methods to define and phylogenetically reconstruct an optimal range-expansion phenotype. Our results indicate that lineage-specific range-shifting abilities increased through an accumulation of adaptive traits that culminated in such a phenotype. This initiated the episode of global colonization and triggered the major radiation of toads. Evolution toward a range-expansion phenotype might be crucial to understanding both ancient widespread radiations and the evolutionary background of contemporary invasive species such as the cane toad.
最近的研究表明，分布区扩张是物种形成的一个潜在驱动因素。然而，在相同的外在环境下，生物类群地理移动的不同倾向是如何产生的，以及它们如何随后影响生物多样性，这些仍知之甚少。我们确定了多个可以预测现存蟾蜍（Bufonidae）物种分布范围的特征，并使用统计方法来定义和系统发育重建最佳的分布扩张表型。我们的研究结果表明，通过积累适应性特征，特定谱系的分布范围转移能力逐渐增强，最终形成了这种表型。这启动了全球殖民化的阶段，并引发了蟾蜍的主要辐射。向分布扩张表型的进化可能对于理解古代广泛的辐射以及当今入侵物种（如甘蔗蟾蜍）的进化背景至关重要。
