The Nuanced Evolutionary Consequences of Duplicated Genes

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Even before experimental biologists had characterised the molecular architecture ofgenes, gene duplication had already been proposed as an important driver for organismal evolution.Early proponents of Darwinian natural selection knew that traits were passed down throughgenerations via a set of instructions, but it was subsequently appreciated that the possibility ofmaking changes to this hereditary material would become increasingly limited as organisms becameadapted to their environment over time. In this way, natural selection was considered first andforemost to be inherently conservative. Freeing the potential for adaptation from the shackles ofconservation is to be thought to be gene duplication. A gene duplication is the complete or partialcopying of a DNA sequence on a chromosome, after which each gene evolves separately to formparalogues. However, it is still not known how gene duplications catalyse multifaceted evolutionaryprocesses such as speciation, especially in light of how many paralogous genes maintain redundancywith one another over long evolutionary timescales. Thus, in order to appreciate the role of geneduplications in complex evolutionary events, it is important to first understand the relationshipsbetween paralogous genes using robust molecular genetic techniques. My work thus far incharacterising the redundancy relationships between members of a large developmental gene familyin the nematode, Caenorhabditis elegans, has shown that the fates of duplicated genes are morenuanced than previously proposed, often exhibiting complex and unexpected redundancyrelationships due to surprising patterns of specialisation. Building on the insights gained from thiswork, I hope to continue to illuminate gene duplication dynamics and their impact on organismalevolution.