Monochromaticity in Neutral Evolutionary Network Models

TL;DR

This study investigates whether monochromaticity in epistatic networks can arise from neutral evolution by proposing and analyzing three Duplication-Divergence inspired models, finding they produce networks similar to real organisms.

Contribution

The paper introduces three new neutral evolutionary network models that explain monochromaticity as a natural outcome of neutral processes.

Findings

Models produce monochromaticity conflict distributions centered near zero.

One model yields strictly monochromatic networks.

Results align with monochromaticity observed in real organisms.

Abstract

Recent studies on epistatic networks of model organisms have unveiled a certain type of modular property called monochromaticity in which the networks are clusterable into functional modules that interact with each other through the same type of epistasis. Here we propose and study three epistatic network models that are inspired by the Duplication-Divergence mechanism to gain insight into the evolutionary basis of monochromaticity and to test if it can be explained as the outcome of a neutral evolutionary hypothesis. We show that the epistatic networks formed by these stochastic evolutionary models have monochromaticity conflict distributions that are centered close to zero and are statistically significantly different from their randomized counterparts. In particular, the last model we propose yields a strictly monochromatic solution. Our results agree with the monochromaticity findings in real organisms and point toward the possible role of a neutral mechanism in the evolution of this phenomenon.