Metabolic theory of ecology

The metabolic theory of ecology suggests that an organism's metabolic rate—how quickly it uses energy—scales predictably with its size and temperature. This means larger animals tend to use energy more slowly per unit body mass than smaller ones, and warm-blooded species have higher metabolic rates than cold-blooded ones. Because energy use influences growth, reproduction, and survival, this theory helps explain patterns in ecosystems, such as how populations grow, how food webs are structured, and how environmental factors affect living organisms across different scales.