鸣禽是如何从澳洲扩散到地球上其它地方的？

鸣禽起源于澳大利亚，那么它们是如何从澳大利亚扩撒到地球上其它地方的呢？来自美国堪萨斯大学等研究机构的科学家利用上千个DNA序列和化石的信息，回答了上述问题。他们发现澳大利亚的鸣禽在3300万年前开始快速分化，并且在2300万年前往澳大利亚以外的地区扩散，首先进入亚洲，然后扩散到世界上的其它区域。

Tectonic collision and uplift of Wallacea triggered the global songbird radiation

Abstract： Songbirds (oscine passerines) are the most species-rich and cosmopolitan bird group, comprising almost half of global avian diversity. Songbirds originated in Australia, but the evolutionary trajectory from a single species in an isolated continent to worldwide proliferation is poorly understood. Here, we combine the first comprehensive genome-scale DNA sequence data set for songbirds, fossil-based time calibrations, and geologically informed biogeographic reconstructions to provide a well-supported evolutionary hypothesis for the group. We show that songbird diversification began in the Oligocene, but accelerated in the early Miocene, at approximately half the age of most previous estimates. This burst of diversification occurred coincident with extensive island formation in Wallacea, which provided the first dispersal corridor out of Australia, and resulted in independent waves of songbird expansion through Asia to the rest of the globe. Our results reconcile songbird evolution with Earth history and link a major radiation of terrestrial biodiversity to early diversification within an isolated Australian continent.

论文链接如下：http://www.nature.com/ncomms/2016/160830/ncomms12709/full/ncomms12709.html

相关报道：University of Kansas. "How songbirds island-hopped out of Australia." ScienceDaily. ScienceDaily, 30 August 2016. <www.sciencedaily.com/releases/2016/08/160830113244.htm>.