The impact of dormancy on evolutionary branching

TL;DR

This paper explores how dormancy influences evolutionary branching by extending adaptive dynamics models, showing dormancy promotes diversification, affects adaptation speed, and alters population structure.

Contribution

It derives a new criterion for evolutionary branching considering dormancy, extending previous models, and analyzes its effects on speciation and diversity.

Findings

Dormancy enlarges the parameter range for evolutionary branching.

Dormancy increases the diversity and genetic distance between subpopulations.

Dormancy can either increase or decrease the speed of adaptation depending on parameters.

Abstract

In this paper, we investigate the consequences of dormancy in the `rare mutation' and `large population' regime of stochastic adaptive dynamics. Starting from an individual-based micro-model, we first derive the polymorphic evolution sequence of the population, based on previous work by Baar and Bovier (2018). After passing to a second `small mutations' limit, we arrive at the canonical equation of adaptive dynamics, and state a corresponding criterion for evolutionary branching, extending a previous result of Champagnat and M\'el\'eard (2011). The criterion allows a quantitative and qualitative analysis of the effects of dormancy in the well-known model of Dieckmann and Doebeli (1999) for sympatric speciation. In fact, a quite intuitive picture merges: Dormancy enlarges the parameter range for evolutionary branching, increases the carrying capacity and niche width of the post-branching sub-populations, and, depending on the model parameters, can either increase or decrease the `speed of adaptation' of populations. Finally, dormancy increases diversity by increasing the genetic distance between subpopulations.