Field Jared M, Bonsall Michael B
Wolfson Centre for Mathematical Biology Mathematical Institute University of Oxford Oxford UK.
Mathematical Ecology Research Group Department of Zoology University of Oxford Oxford UK.
Ecol Evol. 2017 Apr 10;7(10):3574-3578. doi: 10.1002/ece3.2958. eCollection 2017 May.
The provision of intergenerational care, via the Grandmother Hypothesis, has been implicated in the evolution of postfertile longevity, particularly in humans. However, if grandmothering does provide fitness benefits, a key question is why has it evolved so infrequently? We investigate this question with a combination of life-history and evolutionary game theory. We derive simple eligibility and stability thresholds, both of which must be satisfied if intergenerational care is first to evolve and then to persist in a population. As one threshold becomes easier to fulfill, the other becomes more difficult, revealing a conflict between the two. As such, we suggest that, in fact, we should expect the evolution of grandmothering to be rare.
通过祖母假说提供的代际照料被认为与绝经后长寿的进化有关，尤其是在人类中。然而，如果祖母照料确实能带来适应性益处，一个关键问题是为什么它如此罕见地进化出来？我们结合生命史和进化博弈论来研究这个问题。我们推导出了简单的资格门槛和稳定性门槛，如果代际照料要首先进化并随后在种群中持续存在，这两个门槛都必须得到满足。当一个门槛变得更容易满足时，另一个门槛就会变得更难，这揭示了两者之间的冲突。因此，我们认为，事实上，我们应该预期祖母照料的进化是罕见的。
