Speaker
Description
In addition to its genetic basis, the phenotype on which evolutionary rescue is contingent can depend on non-genetic factors. These exist at different levels of biological organization, including epigenetics (e.g., DNA methylation), cellular and developmental processes (e.g., morphogenesis), behaviour (e.g., cultural traits like tool use), and inter and intra-species interactions (e.g., microbiome). Importantly, these non-genetic mechanisms allow the same genotype to result in multiple phenotypes within the same environment (phenotypic variability) or in different environments (phenotypic plasticity). These changes are not completely dependent on genetic changes and hence can respond to the environmental shift more rapidly. However, the consequences of these rapid changes for survival are non-trivial and depend on the mechanistic underpinning of the non-genetic factor, its interaction with genetic factors, its distinct inheritance patterns, and the timescale of phenotypic changes it causes. Here, I will outline a wide variety of non-genetic factors, discuss existing theory and present two models of evolutionary rescue where the phenotype is composed of a genetic and non-genetic component. The first will focus on a discrete trait with an epigenetic component incorporating multiple epigenetic mechanisms. Increasing epigenetic modification rate has a non-monotonic effect on rescue depending on its interaction with the genetic component and the environment, highlighting the importance of mechanistically modelling such non-genetic factors. The second model will be a general framework for analysing a broad variety of non-genetic factors. Finally, I will discuss the empirical evidence for these non-genetic components in the context of evolutionary rescue highlighting key gaps and open questions.