Data from: Ephemeral ecological speciation and the latitudinal biodiversity gradient

The richness of biodiversity in the tropics compared to high latitude parts of the world forms one of the most globally conspicuous patterns in biology, and yet few hypotheses aim to explain this phenomenon in terms of explicit micro-evolutionary mechanisms of speciation and extinction. We link population genetic processes of selection and adaptation to speciation and extinction by way of their interaction with environmental factors to drive global scale macro-ecological patterns. High latitude regions are both cradle and grave with respect to species diversification. In particular, we point to a conceptual equivalence of ‘environmental harshness’ and ‘hard selection’ as eco-evolutionary drivers of local adaptation and ecological speciation. By describing how ecological speciation likely occurs more readily at high latitudes, with such nascent species especially prone to extinction by fusion, we derive the ephemeral ecological speciation hypothesis as an integrative mechanistic explanation for latitudinal gradients in species turnover and the net accumulation of biodiversity.

与全球高纬度区域相比，热带地区的生物多样性丰度构成了生物学领域最显著的全球分布格局之一，但目前鲜有假说通过物种形成与灭绝的明确微观进化机制来解释这一现象。我们将选择与适应的种群遗传过程，通过其与环境因子的相互作用，与物种形成和灭绝过程关联起来，以此驱动全球尺度的宏观生态学格局。就物种多样化而言，高纬度区域既是物种起源的摇篮，也是物种消亡的坟场。具体而言，我们提出"环境严苛性"与"硬性选择（hard selection）"在概念上等价，二者均可作为驱动局部适应与生态物种形成的生态进化驱动因子。通过阐释生态物种形成更易在高纬度区域发生，且此类新生物种极易因融合作用走向灭绝，我们推导出"短暂生态物种形成假说"，以此作为解释物种周转与生物多样性净积累纬度梯度的整合性机制性解释。