The genomic architecture and evolutionary fates of supergenes

TL;DR

This review explores how the genomic structure of supergenes influences their evolution, degeneration, and long-term stability across diverse species, integrating recent genomic findings with theoretical models.

Contribution

It synthesizes recent genomic data and models to elucidate how supergene architecture impacts their evolutionary outcomes and degeneration processes.

Findings

Genomic architecture affects supergene degeneration rates.

Differences in architecture influence evolutionary trajectories.

Simulations demonstrate architecture's role in haplotype degeneration.

Abstract

Supergenes are genomic regions containing sets of tightly linked loci that control multi-trait phenotypic polymorphisms under balancing selection. Recent advances in genomics have uncovered significant variation in both the genomic architecture as well as the mode of origin of supergenes across diverse organismal systems. Although the role of genomic architecture for the origin of supergenes has been much discussed, differences in the genomic architecture also subsequently affect the evolutionary trajectory of supergenes and the rate of degeneration of supergene haplotypes. In this review, we synthesize recent genomic work and historical models of supergene evolution, highlighting how the genomic architecture of supergenes affects their evolutionary fate. We discuss how recent findings on classic supergenes involved in governing ant colony social form, mimicry in butterflies, and heterostyly in flowering plants relate to theoretical expectations. Furthermore, we use forward simulations to demonstrate that differences in genomic architecture affect the degeneration of supergenes. Finally, we discuss implications of the evolution of supergene haplotypes for the long-term fate of balanced polymorphisms governed by supergenes.