postreproductive

Postreproductive refers to the phase of an organism’s life after the end of its reproductive period. In life-history theory, species vary in how long individuals remain reproductively capable, and in many species the postreproductive lifespan is negligible or absent. In humans, menopause marks the transition to the postreproductive period, with fertility ending in midlife while lifespan continues for decades. The term encompasses the years after the last potential reproductive event.

In humans, the postreproductive phase has been discussed for potential evolutionary significance, including the grandmother hypothesis, which proposes that women who survive beyond reproduction can increase the survival and reproductive success of their descendants by aiding offspring. In other species, postreproductive lifespans are more or less pronounced. Some toothed whales, such as orcas, and certain baleen whales display substantial postreproductive lifespans, contributing to social knowledge transfer and group coordination. By contrast, many animals die soon after reproduction or show reproductive senescence earlier in life.

Measuring postreproductive longevity often uses the concept of the postreproductive stage, defined as the period after last reproduction. In ecology and demography, recognizing a postreproductive phase helps describe life-history strategies, social structures, and population dynamics.