An organism's ecology is fundamentally constrained by its metabolism, which determines its ability to take up and transform sources of material and energy. What if an organism's metabolism could be extended, within its lifetime, through interactions with other species? My talk explores this "acquired metabolism," which may be obtained through gene transfer, the theft of cellular machinery, or the formation of metabolic mutualisms. I describe how such acquisitions can transform the fundamental niche of a species, with implications for community dynamics and ecosystem function, and highlight how our understanding of this phenomenon can contribute to a broader theory of community ecology.