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Abstract：
Diatoms are single-celled organisms that contribute approximately 20% of the global primary production and play a crucial role in biogeochemical cycles and trophic chains. Despite their ecological importance, our knowledge of microevolution is limited. We developed a model using the SLiM evolutionary framework to address this knowledge gap. As a reference, we used the diatom Pseudo-nitzschia multistriata, which has been extensively studied in the Gulf of Naples. Our model recapitulates what we observe in natural populations, with microevolutionary processes that occur annually during a three-stage bloom phase. Interestingly, we found that non-bloom phases allow the population to maintain sex-generated diversity produced during blooms. This finding suggests that non-bloom phases are critical to counteract bloom-related pressures and mitigate genetic divergence at the species level. Moreover, our model showed that despite the consistent genetic differentiation during bloom phases, the population tends to return to pre-bloom states. While our model is limited to neutral dynamics, our study provides valuable insights into diatoms\' microevolution, paving the way to explore the ecological implications of the life history dynamics of these organisms.
摘要：
硅藻是单细胞生物，约占全球初级生产的20％，在生物地球化学循环和营养链中起着至关重要的作用。尽管它们的生态重要性，我们的微进化知识是有限的。我们使用SLiM进化框架开发了一个模型来解决这一知识差距。作为参考,我们用的是硅藻伪氮菌,在那不勒斯湾进行了广泛的研究。我们的模型概括了我们在自然种群中观察到的情况，微进化过程每年发生在三个阶段的开花阶段。有趣的是,我们发现，非开花阶段允许种群维持开花期间产生的性别产生的多样性。这一发现表明，非开花阶段对于抵消与开花相关的压力和减轻物种水平的遗传差异至关重要。此外，我们的模型表明，尽管在开花阶段有一致的遗传分化，人口倾向于恢复到开花前的状态。虽然我们的模型仅限于中性动力学，我们的研究为硅藻微进化提供了有价值的见解，为探索这些生物的生活史动态的生态意义铺平道路。
