Neutral networks of genotypes: Evolution behind the curtain

TL;DR

This paper explores how neutral networks of genotypes facilitate evolutionary processes, revealing that organisms can explore genetic space without immediate phenotypic change, which may explain rapid speciation after long periods of stasis.

Contribution

It introduces the concept of neutral networks in genotype space and discusses their role in evolution, challenging classical models that assume a single optimal genotype.

Findings

Neutral networks allow access to diverse genotypes with the same phenotype.

Genetic exploration through neutral networks can lead to rapid speciation.

Classical evolutionary models may need revision to incorporate neutral network dynamics.

Abstract

Our understanding of the evolutionary process has gone a long way since the publication, 150 years ago, of "On the origin of species" by Charles R. Darwin. The XXth Century witnessed great efforts to embrace replication, mutation, and selection within the framework of a formal theory, able eventually to predict the dynamics and fate of evolving populations. However, a large body of empirical evidence collected over the last decades strongly suggests that some of the assumptions of those classical models necessitate a deep revision. The viability of organisms is not dependent on a unique and optimal genotype. The discovery of huge sets of genotypes (or neutral networks) yielding the same phenotype --in the last term the same organism--, reveals that, most likely, very different functional solutions can be found, accessed and fixed in a population through a low-cost exploration of the space of genomes. The 'evolution behind the curtain' may be the answer to some of the current puzzles that evolutionary theory faces, like the fast speciation process that is observed in the fossil record after very long stasis periods.