Simulating short- and long-term evolutionary dynamics on rugged landscapes

TL;DR

This paper introduces a minimal model simulating evolutionary dynamics on rugged landscapes, capturing long waiting times and bursts of adaptation driven by point mutations and chromosomal inversions, reflecting evolutionary innovation and punctuated equilibrium.

Contribution

The model combines point mutations and inversions to simulate long-term evolutionary dynamics on NK landscapes, highlighting different time scales and the role of chromosomal rearrangements.

Findings

Long-term waiting periods precede bursts of adaptation.

Inversions can trigger successive point mutations.

Gene epistasis influences evolutionary time scales.

Abstract

We propose a minimal model to simulate long waiting times followed by evolutionary bursts on rugged landscapes. It combines point and inversions-like mutations as sources of genetic variation. The inversions are intended to simulate one of the main chromosomal rearrangements. Using the well-known family of NK fitness landscapes, we simulate random adaptive walks, i.e. successive mutational events constrained to incremental fitness selection. We report the emergence of different time scales: a short-term dynamics mainly driven by point mutations, followed by a long-term (stasis-like) waiting period until a new mutation arises. This new mutation is an inversion which can trigger a burst of successive point mutations, and then drives the system to new short-term increasing-fitness period. We analyse the effect of genes epistatic interactions on the evolutionary time scales. We suggest that the present model mimics the process of evolutionary innovation and punctuated equilibrium.