The dynamics of starvation and recovery

TL;DR

This paper introduces a nutritional state-structured model linking starvation, recovery, and reproduction to eco-evolutionary dynamics, predicting population stability and maximum mammalian size through allometric scaling.

Contribution

The study develops a novel state-structured model incorporating nutritional states, deriving constraints on rates, and explaining size evolution and stability in populations.

Findings

Population dynamics tend toward a steady state.

Rates fall within a 'refuge' minimizing extinction risk.

Model predicts maximum mammalian body size and supports Cope's rule.

Abstract

The eco-evolutionary dynamics of species are fundamentally linked to the energetic constraints of its constituent individuals. Of particular importance is the interplay between reproduction and the dynamics of starvation and recovery. To elucidate this interplay, we introduce a nutritional state-structured model that incorporates two classes of consumer: nutritionally replete, reproducing consumers, and undernourished, non-reproducing consumers. We obtain strong constraints on starvation and recovery rates by deriving allometric scaling relationships and find that population dynamics are typically driven to a steady state. Moreover, these rates fall within a 'refuge' in parameter space, where the probability of population extinction is minimized. We also show that our model provides a natural framework to predict maximum mammalian body size by determining the relative stability of an otherwise homogeneous population to a competing population with altered percent body fat. This framework provides a principled mechanism for a selective driver of Cope's rule.