Beaugrand Gregory, Kirby Richard, Goberville Eric
LOG Laboratoire d'Océanologie et de Géosciences CNRS UMR 8187 Wimereux France.
The Secchi Disk Foundation Plymouth UK.
Ecol Evol. 2020 Jun 11;10(13):6494-6511. doi: 10.1002/ece3.6385. eCollection 2020 Jul.
Although we understand how species evolve, we do not appreciate how this process has filled an empty world to create current patterns of biodiversity. Here, we conduct a numerical experiment to determine why biodiversity varies spatially on our planet. We show that spatial patterns of biodiversity are mathematically constrained and arise from the interaction between the species' ecological niches and environmental variability that propagates to the community level. Our results allow us to explain key biological observations such as (a) latitudinal biodiversity gradients (LBGs) and especially why oceanic LBGs primarily peak at midlatitudes while terrestrial LBGs generally exhibit a maximum at the equator, (b) the greater biodiversity on land even though life first evolved in the sea, (c) the greater species richness at the seabed than at the sea surface, and (d) the higher neritic (i.e., species occurring in areas with a bathymetry lower than 200 m) than oceanic (i.e., species occurring in areas with a bathymetry higher than 200 m) biodiversity. Our results suggest that a mathematical constraint originating from a fundamental ecological interaction, that is, the niche-environment interaction, fixes the number of species that can establish regionally by speciation or migration.
尽管我们了解物种是如何进化的，但我们并不清楚这个过程是如何使一个空旷的世界变得充实，从而形成当前的生物多样性格局的。在此，我们进行了一项数值实验，以确定地球上生物多样性在空间上为何会有所不同。我们表明，生物多样性的空间格局在数学上是受约束的，并且源于物种生态位与传播到群落层面的环境变异性之间的相互作用。我们的研究结果使我们能够解释一些关键的生物学现象，例如：（a）纬度生物多样性梯度（LBGs），尤其是为什么海洋LBGs主要在中纬度地区达到峰值，而陆地LBGs通常在赤道处呈现最大值；（b）尽管生命最初在海洋中进化，但陆地上的生物多样性更为丰富；（c）海底的物种丰富度高于海面；以及（d）浅海（即出现在水深低于200米区域的物种）的生物多样性高于远洋（即出现在水深高于200米区域的物种）。我们的研究结果表明，源自一种基本生态相互作用（即生态位 - 环境相互作用）的数学约束，决定了通过物种形成或迁移能够在区域内建立的物种数量。
