Laurence Hurst works on fundamental problems in the evolution of genetic systems, such as understanding why some sorts of mutations are less damaging than predicted whilst others are more damaging. Mutations that change proteins are, surprisingly, often not especially deleterious. Laurence showed that this was because the genetic code is structured in a way that renders it highly error-proof. Similarly, in applying network representations of gene interactions, he revealed why many deletions of genes have little effect and which deletions tend not to be recessive.

By contrast, Laurence revealed that genomic changes often considered to be relatively harmless — such as gene order changes and mutations at ‘silent’ sites — are under selection for unanticipated reasons. He also showed how synonymous mutations can disrupt the way gene transcripts are processed. Similarly, in showing that genomes are arranged into gene expression domains, Laurence revealed that genes can affect the expression of other genes in their vicinity. Translation of this fundamental work to medicine is a focus of his current research.