The Changing Geometry of a Fitness Landscape Along an Adaptive Walk

TL;DR

This paper demonstrates that the changing prevalence of epistasis during adaptive walks is a general phenomenon explained by mean regression, supported by simulations and relevant to empirical studies.

Contribution

It introduces a simple, general explanation for the variation in epistasis along adaptive walks, extending previous NK model insights.

Findings

Epistasis prevalence varies along adaptive walks.

Mean regression explains the observed pattern.

Supported by simulation results.

Abstract

It has recently been noted that the relative prevalence of the various kinds of epistasis varies along an adaptive walk. This has been explained as a result of mean regression in NK model fitness landscapes. Here we show that this phenomenon occurs quite generally in fitness landscapes. We propose a simple and general explanation for this phenomemon, confirming the role of mean regression. We provide support for this explanation with simulations, and discuss the empirical relevance of our findings.