The early-life environment and individual plasticity in life history

We tested whether the early-life environment can influence the extent of individual plasticity in a life history trait. We asked: can the early-life environment explain why, in response to the same adult environmental cue, some individuals invest more than others in current reproduction? And can it additionally explain why investment in current reproduction trades off against survival in some individuals, but is positively correlated with survival in others? We addressed these questions using the burying beetle, which breeds on small carcasses and sometimes carries phoretic mites. These mites breed alongside the beetle, on the same resource, and are a key component of the beetle’s early-life environment. We exposed female beetles to mites twice during their lives: during their development as larvae, and again as adults during their first reproductive event. We measured investment in current reproduction by quantifying average larval mass, and recorded the female’s lifespan after breedin...