Evolution by gene duplication: in the era of genomics

Gene duplication is the process of a gene copied via specific molecular mechanisms to form more duplicate genes. As an important approach to the origination of new genes, gene duplication contributes to around half of the genes in eukaryotic genomes, facilitating the adaptive evolution of species. Over the past fifty years, especially since entering the genomics era in the last two decades, there have been extensive and profound discussions on the mechanisms, evolutionary processes and forces behind the emergence of duplicate genes. Sequence similarity of duplicate genes often leads to functional redundancy, enhancing organismal robustness. Conversely, functional divergence can create novel functions and improve evolvability. In this review, we summarize the mechanism of gene duplication, the fate and the evolutionary models of duplicate genes. This article concludes by outlining how long-read sequencing technologies, gene editing, and various other high-throughput techniques will further advance our understanding of the role of duplicate genes in the genetics-development-evolution network.