Learning Mitigates Genetic Drift

Abstract

Genetic drift is a basic evolutionary principle describing random changes in allelic frequencies, with far-reaching consequences in various topics ranging from species conservation efforts to speciation. The conventional approach assumes that genetic drift has the same effect on all populations undergoing the same change in size, regardless of different behaviors and history of the populations. However, here we reason that processes leading to a systematic increase of individuals chances of survival, such as learning or immunological memory, can mitigate the effects of genetic drift even if the overall mortality rate in the population does not change. We further test this notion in an agent-based model monitoring allele frequencies in a population of prey, either able or not able to learn. Importantly, both these populations start with the same effective size and have the same and constant overall mortality rates. Our results demonstrate that even under these conditions, learning can mitigate drift if generations overlap. Furthermore, this effect holds regardless if the population is haploid or diploid or whether it reproduces sexually or asexually. Therefore, our findings demonstrate that learning is an overlooked factor affecting the effective population size. These findings may be of importance not only for basic evolutionary theory but also for other fields using the concept of genetic drift.