The article by Jonathan M. Chase explores the role of stochastic ecological drift and priority effects in community assembly, particularly in the context of drought. Historically, community composition was thought to be primarily influenced by deterministic factors such as niche interactions and environmental conditions. However, recent studies have highlighted the importance of stochastic processes like birth, death, colonization, and extinction (ecological drift). Chase proposes that the relative importance of these stochastic processes depends on the severity of ecological filters in a habitat. To test this hypothesis, he conducted a long-term experiment in artificial ponds, manipulating community assembly and drought conditions. In the experiment, ponds were established and allowed to assemble over two years, with species introduced randomly at different times to maximize the potential for stochastic ecological drift and priority effects. After the initial assembly, half of the ponds experienced drought, while the other half remained permanent. The results showed that drought significantly reduced species richness and increased site-to-site variation in community composition, likely due to the elimination of species that could not tolerate harsh conditions. In contrast, permanent ponds exhibited more variable community compositions, suggesting a stronger influence of ecological drift and priority effects. Chase concludes that drought acts as a critical environmental filter, reducing the pool of species that can persist and increasing the similarity among communities. This finding has implications for understanding biodiversity patterns at different spatial scales and for biodiversity restoration efforts, which must consider both stochastic and deterministic processes. The study emphasizes the importance of recognizing the varied influences of ecological forces, such as disturbance, on biodiversity patterns in response to human activities.The article by Jonathan M. Chase explores the role of stochastic ecological drift and priority effects in community assembly, particularly in the context of drought. Historically, community composition was thought to be primarily influenced by deterministic factors such as niche interactions and environmental conditions. However, recent studies have highlighted the importance of stochastic processes like birth, death, colonization, and extinction (ecological drift). Chase proposes that the relative importance of these stochastic processes depends on the severity of ecological filters in a habitat. To test this hypothesis, he conducted a long-term experiment in artificial ponds, manipulating community assembly and drought conditions. In the experiment, ponds were established and allowed to assemble over two years, with species introduced randomly at different times to maximize the potential for stochastic ecological drift and priority effects. After the initial assembly, half of the ponds experienced drought, while the other half remained permanent. The results showed that drought significantly reduced species richness and increased site-to-site variation in community composition, likely due to the elimination of species that could not tolerate harsh conditions. In contrast, permanent ponds exhibited more variable community compositions, suggesting a stronger influence of ecological drift and priority effects. Chase concludes that drought acts as a critical environmental filter, reducing the pool of species that can persist and increasing the similarity among communities. This finding has implications for understanding biodiversity patterns at different spatial scales and for biodiversity restoration efforts, which must consider both stochastic and deterministic processes. The study emphasizes the importance of recognizing the varied influences of ecological forces, such as disturbance, on biodiversity patterns in response to human activities.