Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, United Kingdom.
Proc Natl Acad Sci U S A. 2023 Aug 15;120(33):e2306220120. doi: 10.1073/pnas.2306220120. Epub 2023 Aug 3.
The latitudinal diversity gradient (LDG) describes the pattern of increasing numbers of species from the poles to the equator. Although recognized for over 200 years, the mechanisms responsible for the largest-scale and longest-known pattern in macroecology are still actively debated. I argue here that any explanation for the LDG must invoke differential rates of speciation, extinction, extirpation, or dispersal. These processes themselves may be governed by numerous abiotic or biotic factors. Hypotheses that claim not to invoke differential rates, such as 'age and area' or 'time for diversification', eschew focus from rate variation that is assumed by these explanations. There is still significant uncertainty in how rates of speciation, extinction, extirpation, and dispersal have varied regionally over Earth history. However, to better understand the development of LDGs, we need to better constrain this variation. Only then will the drivers of such rate variation - be they abiotic or biotic in nature - become clearer.
纬度多样性梯度（LDG）描述了从两极到赤道物种数量增加的模式。尽管这一模式已经被认识了 200 多年，但负责这一最大规模和最长已知的宏观生态学模式的机制仍在激烈争论中。我在这里认为，任何对 LDG 的解释都必须涉及到不同的物种形成、灭绝、绝灭或扩散速度。这些过程本身可能受到许多非生物或生物因素的控制。那些声称不涉及速度差异的假说，如“年龄和面积”或“多样化时间”，回避了这些解释所假设的速度变化的焦点。在地球历史上，物种形成、灭绝、绝灭和扩散的速度在区域上是如何变化的，仍然存在很大的不确定性。然而，为了更好地理解 LDG 的发展，我们需要更好地约束这种变化。只有这样，这些速度变化的驱动因素——无论是生物的还是非生物的——才会变得更加清晰。
