Life History Theory is a framework in evolutionary biology that explains how organisms allocate their resources to growth, reproduction, and survival. It suggests that different species have evolved various strategies to maximize their reproductive success based on environmental conditions. For example, some species, like tortoises, may invest heavily in long lifespans and fewer offspring, while others, like fruit flies, produce many offspring quickly but live shorter lives. This theory helps scientists understand the trade-offs organisms face, such as the balance between investing energy in raising young versus developing their own bodies. By studying these strategies, researchers can gain insights into the evolutionary pressures that shape the life cycles of different species, including humans.