School of Life Sciences, University of Lincoln, Brayford Campus, Lincoln, LN6 7DL, United Kingdom.
Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
Sci Rep. 2019 Mar 25;9(1):5093. doi: 10.1038/s41598-019-41670-8.
Anthropogenic climate change ranks among the major global-scale threats to modern biodiversity. Extinction risks are known to increase via the interactions between rapid climatic alterations and environmentally-sensitive species traits that fail to adapt to those changes. Accumulating evidence reveals the influence of ecophysiological, ecological and phenological factors as drivers underlying demographic collapses that lead to population extinctions. However, the extent to which life-history traits influence population responses to climate change remains largely unexplored. The emerging 'cul-de-sac hypothesis' predicts that reptilian viviparity ('live-bearing' reproduction), a 'key innovation' facilitating historical invasions of cold climates, increases extinction risks under progressively warming climates compared to oviparous reproduction - as warming advances polewards/mountainwards, historically cold-climates shrink, leading viviparous species to face demographic collapses. We present the first large-scale test of this prediction based on multiple lizard radiations and on future projections of climate-based ecological niche models. Viviparous species were found to experience stronger elevational range shifts (and potentially increased extinctions) in coming decades, compared to oviparous lizards. Therefore, our analyses support the hypothesis's fundamental prediction that elevational shifts are more severe in viviparous species, and highlight the role that life-history adaptations play in the responses of biodiversity to ongoing climate change.
人为气候变化是现代生物多样性面临的主要全球性威胁之一。众所周知，快速的气候变化与无法适应这些变化的环境敏感物种特征之间的相互作用会增加灭绝风险。越来越多的证据表明，生理生态、生态和物候因素的影响是导致种群灭绝的人口崩溃的驱动因素。然而，生活史特征在多大程度上影响种群对气候变化的反应在很大程度上仍未得到探索。新兴的“死胡同假说”预测，爬行动物的胎生（“活体繁殖”），一种促进历史上对寒冷气候入侵的“关键创新”，与卵生繁殖相比，在逐渐变暖的气候下会增加灭绝风险——随着变暖向极地/山地推进，历史上的寒冷气候缩小，导致胎生物种面临人口崩溃。我们基于多个蜥蜴辐射和未来气候生态位模型的预测，首次对这一预测进行了大规模检验。与卵生蜥蜴相比，胎生蜥蜴在未来几十年将经历更强的海拔范围转移（可能增加灭绝）。因此，我们的分析支持了该假说的基本预测，即胎生物种的海拔转移更为严重，并强调了生活史适应在生物多样性对正在进行的气候变化的反应中所起的作用。
