Evolution with recombination as a Metropolis-Hastings sampling procedure

TL;DR

This paper introduces a population genetic model incorporating recombination as a Metropolis-Hastings sampling process, enabling exact analysis of equilibrium distributions under various fitness functions.

Contribution

It develops a novel analytical framework for population genetics using n-parent recombination and Metropolis-Hastings sampling, allowing exact solutions for complex fitness landscapes.

Findings

Exact stationary distributions derived for multiple fitness functions

Analysis of linkage disequilibrium and metastability in populations

Method applicable to finite and infinite populations

Abstract

This work presents a population genetic model of evolution, which includes haploid selection, mutation, recombination, and drift. The mutation-selection equilibrium can be expressed exactly in closed form for arbitrary fitness functions without resorting to diffusion approximations. Tractability is achieved by generating new offspring using n-parent rather than 2-parent recombination. While this enforces linkage equilibrium among offspring, it allows analysis of the whole population under linkage disequilibrium. We derive a general and exact relationship between fitness fluctuations and response to selection. Our assumptions allow analytical calculation of the stationary distribution of the model for a variety of non-trivial fitness functions. These results allow us to speak to genetic architecture, i.e., what stationary distributions result from different fitness functions. This paper presents methods for exactly deriving stationary states for finite and infinite populations. This method can be applied to many fitness functions, and we give exact calculations for four of these. These results allow us to investigate metastability, tradeoffs between fitness functions, and even consider error-correcting codes