Department of Geological Sciences & Engineering, University of Nevada - Reno, Reno, NV, USA.
Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.
Commun Biol. 2023 May 22;6(1):554. doi: 10.1038/s42003-023-04871-6.
A major premise of ecological neutral theory is that population size is inversely related to extinction risk. This idea is central to modern biodiversity conservation efforts, which often rely on abundance metrics to partially determine species extinction risk. However, limited empirical studies have tested whether extinction is indeed more probable for species with low abundances. Here we use the fossil record of Neogene radiolaria to test the relationship between relative abundance and longevity (time from first to last occurrence). Our dataset includes abundance histories for 189 polycystine radiolarian species from the Southern Ocean, and 101 species from the tropical Pacific. Using linear regression analyses, we show that neither maximum nor average relative abundance are significant predictors of longevity in either oceanographic region. This suggests that neutral theory fails to explain the plankton ecological-evolutionary dynamics we observe. Extrinsic factors are likely more important than neutral dynamics in controlling radiolarian extinction.
生态中性理论的一个主要前提是，种群大小与灭绝风险成反比。这个观点是现代生物多样性保护努力的核心，这些努力通常依赖于丰度指标来部分确定物种灭绝风险。然而，有限的实证研究已经检验了灭绝是否确实更可能发生在丰度低的物种身上。在这里，我们利用渐新世放射虫的化石记录来检验相对丰度与长寿（从首次出现到最后一次出现的时间）之间的关系。我们的数据集包括来自南大洋的 189 种多房放射虫物种和来自热带太平洋的 101 种物种的丰度历史。使用线性回归分析，我们表明，在两个海洋区域，最大或平均相对丰度都不是长寿的显著预测因子。这表明中性理论未能解释我们观察到的浮游生物生态进化动态。在控制放射虫灭绝方面，外在因素可能比中性动态更为重要。
