Horvitz, C. | Search bioRxiv

bioRxiv2020

Distributions of LRS in varying environments

Studies of lifetime reproductive success (LRS) have shown that important random events can be in ecology and evolution. Randomness should be amplified in stochastic environments, and here we show here we show this to be the case by computing the complete distribution of LRS when vital rates are Markovian can be readily computed by building on our recent paper (Tuljapurkar et al. 2020). These results complement the work of van Daalen and Caswell (2020) on moments of LRS. We use empirical studies of Roe deer, Capreolus capreolus, to show that environments at birth have strong effects on future performance, and that analyses of the LRS in stochastic environments are a valuable element of studies of the consequences of climate change.

ecology↗

bioRxiv2019

Skewed distributions of LRS: beyond mean and variance

Many field studies find that lifetime reproductive success (LRS) is highly skewed and often multimodal among individuals. Field biologists generate invaluable data on survival and reproductive rates, as a function of age and stage, that are used to parameterise structured models. These models often perform well at predicting population growth and mean LRS, but we do not know whether they accurately predict observed distributions of individual LRS. If the models fail to recreate these distributions, their use may be limited because the LRS is central to understanding life history evolution. We present powerful tools to generate distributions of LRS from age and/or stage structured models. Our methods reveal that structured models do perform well at generating distributions that agree with observations. Our approach also reveals why such skewed distributions arise, and helps resolve a debate about detecting signatures of selection in skewed distributions of LRS.

ecology↗