Life history adaptations to fluctuating environments: Combined effects of demographic buffering and lability of demographic parameters

Abstract

Demographic buffering and lability have both been identified as important adaptive strategies to optimise long-term fitness in variable environments. These strategies are not mutually exclusive, however we lack efficient methods to measure their relative importance. Here, we define a new index to measure the total lability for a given life history, and use stochastic simulations to disentangle relative fitness effects of buffering and lability. The simulations use 81 animal matrix population models, and different scenarios to explore how the strategies vary across life histories. The highest potential for adaptive demographic lability was found for short- to intermediately long-lived species, while demographic buffering was the main response in slow-living species. This study suggests that faster-living species are more responsive to environmental variability, both for positive or negative effects. Our methods and results provide a more comprehensive view of adaptations to variability, of high relevance to predict species responses to climate change.

Current perspectives and future directions in animal life history evolution

“…However, after perusing through the literature, Willow is shocked. The majority of papers on the evolution of life histories focus solely on the first criterion for evolution by natural 16 selection (Barraquand & Yoccoz, 2013;Benton & Grant, 1996;Hilde et al, 2020;Jaggi et al, 2023;Koons et al, 2009;Le Coeur et al, 2022;J. L. McDonald et al, 2017;Morris et al, 2008;Pfister, 1998;Tuljapurkar, Gaillard, et al, 2009).…”