On mechanisms of neutral evolution of DNA resulting in scale-free behaviour

TL;DR

This paper introduces models of DNA evolution with segmental substitutions and point mutations, showing they produce scale-free length distributions of exact matches, which may explain increased genome complexity.

Contribution

The paper presents new models of DNA evolution that reproduce observed power-law distributions of exact match lengths, suggesting mechanisms for genome complexity growth.

Findings

Models reproduce algebraic length distributions with slope -4

Power-law distributions emerge from transfer of DNA content to longer sequences

Potential mechanisms for increased genome complexity identified

Abstract

We introduce a family of models incorporating random segmental substitutions and point mutations and demonstrate that such models reproduce algebraic length distributions of exact matches with the slope $-4$ observed earlier in pairwise comparisons of DNA of distantly related species. It is demonstrated that power-law distributions of exact matches emerge when shorter sequences transfer their DNA content to longer sequences, indicating potential mechanisms of the increased genome complexity.