Why are transposable elements so common, and the genomes so large, in some species but not in others? Transposable elements are selfish genetic elements that can self replicate and insert into new locations in the genome. My work centers on how changes in modes of inheritance, such as the evolution selfing, sex, and increases in ploidy, affect the evolutionary dynamics of transposons. I am also interested in how transposons contribute to variation in genome size, particularly in plants. I have studied these questions in a variety of plant systems, including Arabidopsis, Capsella, and Oenothera.
When are nuclear and mitochondrial genes in conflict? And when will they cooperate? Genomic conflicts often arise because not all genes are inherited in the same way. The conflict between maternally inherited mitochondrial and bi-parentally inherited nuclear genes is one of the best described genomic conflicts in biology. I have investigated how such conflicts can be detected in sequence variation, and in the distribution of cytonuclear genes. Currently, I am using a combination of theory and experimental crosses in Drosophila to test the role of sex chromosome in alleviating the Mother’s Curse (the spread of mitochondrial mutations that are beneficial in females but deleterious in males).
What can selfish genetic elements tell us about the evolution of conflict and cooperation? For the past half century, the study of social evolution has benefited greatly by the so-called gene’s-eye view of evolution. Indeed, the gene’s-eye view was instrumental in bringing selfish genetic elements to the forefront of evolutionary biology and genetics. I am interested in the history of the gene’s-eye view of evolution, especially its relationship with the empirical study of selfish genetic elements (see also here). I am also a member of the international working group Social Evolution and Genome Complexity, which explores the relationship between social behavior and genome evolution. Finally, I am also interested in the broader history of evolutionary biology. To this end, I have written commentaries on books on the life of Bill Hamilton and the Swedish botanist and political radical Bengt Lidforss.