美国德克萨斯大学Michael G. Harvey等研究人员揭示出热带生物多样性热点的演变。这一研究成果于2020年12月11日发表在国际学术期刊《科学》上。

研究人员利用数十年的野外工作收集的样本来研究了最大热带鸟类辐射（suboscine passerines）的多样化。 这些系统发育是根据来自1287个物种的1940只个体的2389个基因组区域数据进行估算的，这揭示了新热带地区suboscine 物种的峰值多样性与近期的物种形成率无关，而是与物种随时间的逐渐积累有关。

矛盾的是，物种形成率最高的是物种多样性较低地区的血统，这些地区通常是寒冷、干燥、不稳定的环境。这些结果揭示了一个模型，即：物种在极端环境中的形成速度更快，但在温和环境中却积累起来，形成热带生物多样性热点。

据了解，热带是大多数生物多样性的来源，但抽样不足掩盖了有关这种多样性如何演变的答案。

附：英文原文

Title: The evolution of a tropical biodiversity hotspot

Author: Michael G. Harvey, Gustavo A. Bravo, Santiago Claramunt, Andrés M. Cuervo, Graham E. Derryberry, Jaqueline Battilana, Glenn F. Seeholzer, Jessica Shearer McKay, Brian C. O’Meara, Brant C. Faircloth, Scott V. Edwards, Jorge Pérez-Emán, Robert G. Moyle, Frederick H. Sheldon, Alexandre Aleixo, Brian Tilston Smith, R. Terry Chesser, Luís Fábio Silveira, Joel Cracraft, Robb T. Brumfield, Elizabeth P. Derryberry

Issue&Volume: 2020/12/11

Abstract: The tropics are the source of most biodiversity yet inadequate sampling obscures answers to fundamental questions about how this diversity evolves. We leveraged samples assembled over decades of fieldwork to study diversification of the largest tropical bird radiation, the suboscine passerines. Our phylogeny, estimated using data from 2389 genomic regions in 1940 individuals of 1287 species, reveals that peak suboscine species diversity in the Neotropics is not associated with high recent speciation rates but rather with the gradual accumulation of species over time. Paradoxically, the highest speciation rates are in lineages from regions with low species diversity, which are generally cold, dry, unstable environments. Our results reveal a model in which species are forming faster in environmental extremes but have accumulated in moderate environments to form tropical biodiversity hotspots.

DOI: 10.1126/science.aaz6970

Source: https://science.sciencemag.org/content/370/6522/1343