Evans Sean M, McKenna Caroline, Simpson Stephen D, Tournois Jennifer, Genner Martin J
School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK.
Biosciences, University of Exeter, Exeter, EX4 4QD, UK.
Biol Lett. 2016 Jun;12(6). doi: 10.1098/rsbl.2016.0090.
The Coral Triangle in the Indo-Pacific is a region renowned for exceptional marine biodiversity. The area could have acted as a 'centre of origin' where speciation has been prolific or a 'centre of survival' by providing refuge during major environmental shifts such as sea-level changes. The region could also have acted as a 'centre of accumulation' for species with origins outside of the Coral Triangle, owing to it being at a central position between the Indian and Pacific oceans. Here, we investigated support for these hypotheses using population-level DNA sequence-based reconstructions of the range evolution of 45 species (314 populations) of Indo-Pacific reef-associated organisms. Our results show that populations undergoing the most ancient establishment were significantly more likely to be closer to the centre of the Coral Triangle than to peripheral locations. The data are consistent with the Coral Triangle being a net source of coral-reef biodiversity for the Indo-Pacific region, suggesting that the region has acted primarily as a centre of survival, a centre of origin or both. These results provide evidence of how a key location can influence the large-scale distributions of biodiversity over evolutionary timescales.
印度-太平洋地区的珊瑚三角区是一个以其卓越的海洋生物多样性而闻名的区域。该区域可能曾作为一个“起源中心”，物种形成十分丰富，或者在海平面变化等重大环境变化期间提供避难所，从而成为一个“生存中心”。由于处于印度洋和太平洋之间的中心位置，该区域也可能作为珊瑚三角区以外起源物种的“聚集中心”。在此，我们利用基于种群水平DNA序列的重建方法，对45种（314个种群）印度-太平洋珊瑚礁相关生物的分布范围演化进行研究，以验证这些假设。我们的结果表明，那些经历了最古老定居过程的种群，相较于边缘位置，更有可能靠近珊瑚三角区的中心。这些数据与珊瑚三角区作为印度-太平洋地区珊瑚礁生物多样性的净来源相一致，这表明该区域主要充当了生存中心、起源中心或两者兼具。这些结果提供了证据，证明一个关键位置如何在进化时间尺度上影响生物多样性的大规模分布。
