Segovia Ricardo A, Pennington R Toby, Baker Tim R, Coelho de Souza Fernanda, Neves Danilo M, Davis Charles C, Armesto Juan J, Olivera-Filho Ary T, Dexter Kyle G
School of GeoSciences, University of Edinburgh, Edinburgh, UK.
Instituto de Ecología y Biodiversidad, Santiago, Chile.
Sci Adv. 2020 May 6;6(19):eaaz5373. doi: 10.1126/sciadv.aaz5373. eCollection 2020 May.
The historical course of evolutionary diversification shapes the current distribution of biodiversity, but the main forces constraining diversification are still a subject of debate. We unveil the evolutionary structure of tree species assemblages across the Americas to assess whether an inability to move or an inability to evolve is the predominant constraint in plant diversification and biogeography. We find a fundamental divide in tree lineage composition between tropical and extratropical environments, defined by the absence versus presence of freezing temperatures. Within the Neotropics, we uncover a further evolutionary split between moist and dry forests. Our results demonstrate that American tree lineages tend to retain their ancestral environmental relationships and that phylogenetic niche conservatism is the primary force structuring the distribution of tree biodiversity. Our study establishes the pervasive importance of niche conservatism to community assembly even at intercontinental scales.
进化多样化的历史进程塑造了当前生物多样性的分布，但限制多样化的主要力量仍是一个争论的话题。我们揭示了美洲各地树种组合的进化结构，以评估无法迁移还是无法进化是植物多样化和生物地理学中的主要限制因素。我们发现，热带和温带环境之间在树木谱系组成上存在根本差异，其界定依据是有无冰冻温度。在新热带界内部，我们发现潮湿森林和干燥森林之间存在进一步的进化分化。我们的结果表明，美洲的树木谱系往往保留其祖先的环境关系，并且系统发育生态位保守性是构建树木生物多样性分布的主要力量。我们的研究确立了生态位保守性对群落组装的普遍重要性，即使在洲际尺度上也是如此。
