Erwin Douglas H
Department of Paleobiology, MRC-121, National Museum of Natural History, PO Box 37012, Washington, DC 20013-7012, USA.
Curr Biol. 2009 Jul 28;19(14):R575-83. doi: 10.1016/j.cub.2009.05.047.
The link between biodiversity and climate has been obvious to biologists since the work of von Humboldt in the early 1800s, but establishing the relationship of climate to ecological and evolutionary patterns is more difficult. On evolutionary timescales, climate can affect supply of energy by biotic and abiotic effects. Some of the best evidence for a link between biodiversity and climate comes from latitudinal gradients in diversity, which provide an avenue to explore the more general relationship between climate and evolution. Among the wide range of biotic hypotheses, those with the greatest empirical support indicate that warmer climates have provided the energetic foundation for increased biodiversity by fostering greater population size and thus increased extinction resistance; have increased metabolic scope; have allowed more species to exploit specialized niches as a result of greater available energy; and generated faster speciation and/or lower extinction rates. In combination with geologic evidence for carbon dioxide levels and changing areas of tropical seas, these observations provide the basis for a simple, first-order model of the relationship between climate through the Phanerozoic and evolutionary patterns and diversity. Such a model suggests that we should expect greatest marine diversity during globally warm intervals with dispersed continents, broad shelves and moderately extensive continental seas. Demonstrating a significant evolutionary response to either climate or climatic change is challenging, however, because of continuing uncertainties over patterns of Phanerozoic marine diversity and the variety of factors beyond climate that influence evolution.
自19世纪初冯·洪堡的研究工作以来，生物学家就已清楚地认识到生物多样性与气候之间的联系，但要确定气候与生态和进化模式之间的关系则更为困难。在进化时间尺度上，气候可通过生物和非生物效应影响能量供应。生物多样性与气候之间存在联系的一些最佳证据来自多样性的纬度梯度，这为探索气候与进化之间更普遍的关系提供了一条途径。在众多生物假说中，那些得到最多实证支持的假说表明，温暖的气候通过促进更大的种群规模从而增强灭绝抵抗力，为生物多样性增加提供了能量基础；增加了代谢范围；由于有更多可用能量，使更多物种能够利用特殊生态位；并产生了更快的物种形成速度和/或更低的灭绝率。结合有关二氧化碳水平和热带海洋面积变化的地质证据，这些观察结果为一个简单的一阶模型提供了基础，该模型描述了显生宙时期的气候与进化模式及多样性之间的关系。这样一个模型表明，在全球温暖时期，当大陆分散、陆架宽广且陆缘海适度广阔时，我们应该预期海洋生物多样性最高。然而，要证明对气候或气候变化有显著的进化响应具有挑战性，因为显生宙海洋生物多样性模式以及气候之外影响进化的各种因素仍存在不确定性。
