Are synonymous mutations under selection and if so why?  Are genomes randomly arranged assemblages of genes or is gene order non-random? Why are most genes apparently “redundant”?  My research approaches these and related questions employing mathematical, bioinformatical, systems biological and experimental tools.

Two classes of problem stand out. On the one hand there are features of genetic systems that appear counter-intuitive.  Why, for example, do many single celled organisms have just two mating types and inherit their organelles from just one parent, even when both gametes are the same size? On the other hand I wish to understand whether genes, genomes and genetic systems are shaped by selection (and if so why) or whether they are neutrally evolving traits. I have shown, for example, how the genetic code is well structured to minimize the effects of mistranslation. More recently I have been concerned with the evolution of isochores, of redundancy, of gene content, of selection on synonymous mutations (and codon usage bias) and gene order evolution. A decade ago it was considered that in mammals both gene order and synonymous mutations were neutrally evolving. The research of my group has been important in overturning these positions.  Gene order evolution and mechanisms for selection on synonymous mutations are the focus of much of our current work.