Most ecosystems have permeable boundaries and are influenced by the movement of resources between surrounding environments. Since resource movements can be intermittent in space and time, variability represents a crucial control over how resource availability influences consumer ecology. Different modes of resource variation, such as the duration, type, magnitude, and frequency of resource availability, may lead to different patterns in consumer community structure. Here, I evaluate how different modes of resource variability affect consumers. In chapter 1, I use public data to examine the relationship between resource longevity and rates of molecular evolution among mussels (Mytilidae: Bathymodiolinae) and tubeworms (Siboglinidae), two clades that have diversified across deep-sea environments that persist for different lengths of time, ranging from decades to millennia. I report an inverse relationship between habitat longevity and rates of mitochondrial sequence evolution, supporting the hypothesis that resource longevity structures consumer life- history variation. Chapter 2 evaluates how imported photosynthetic and autochthonous chemosynthetic resources shape crustacean trophic structure in subterranean estuaries. I document evidence of chemosynthetic energy consumption by generalist filter- feeding crustaceans, contradicting traditional notions of caves as extreme cases of subsidy-dependent ecosystems. These findings highlight how consumer functional traits may mediate the effects of resource variability on food web organization. To further examine the consequences of resource variability, I use protist communities that inhabit the pitchers of Sarracenia purpurea to examine how the magnitude (chapter 3) and frequency (chapter 4) of resource pulses impact community organization. Large pulses led to more deterministic patterns in community structure, characterized by dominance of large, fast-moving swimming protists, while small pulses led to greater stochasticity. Resource pulse frequency mediated both taxonomic and functional community structure. High pulse frequency led to more speciose communities due to increased representation of rare taxa. Low frequency pulses led to communities dominated by large, fast-moving ciliates, while high frequency pulses led to more stochasticity and increased representation of smaller, slow-moving amoebae. Overall, these findings demonstrate that different modes of resource variability can fundamentally alter patterns and variability in community organization, improving our ability to anticipate how altered patterns of resource variation may impact communities in the future.