My research lies at the intersection between transmission genetics and social evolution. I am interested in the central question of social evolution of what prevents selfish behaviour from destroying the common good that can be achieved through cooperation plays out at the genetic level. Transmission genetics provide a window into this problem, as genomic conflicts often arise because not all genes are inherited in the same way.
Mother’s Curse and Father’s Curse
The conflict between maternally inherited mitochondrial and bi-parentally inherited nuclear genes is one of the best described genomic conflicts in biology. Because genes in the mitochondrial genome are strictly maternally inherited, mutations that are beneficial in females can spread in a population even if they are deleterious in males. This is the Mother’s Curse. With Andy Clark and Manisha Munasinghe (Cornell), I have used population genetic theory to show how the fate of compensatory nuclear modifier loci that alleviate the effect in males depend on whether they are located on autosomes or sex chromosomes. Our analytical framework also allowed us to discover a novel kind of sexual conflict: Father’s Curse. A major focus of current work is to determine how likely we should be to detect it nature. We are also using experimental crosses in Drosophila to test the extent of mitochondrial-Y chromosome epistatsis.
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 PhD work with Stephen Wright (University of Toronto) centered 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.
What can selfish genetic elements tell us about the evolution of conflict and cooperation?
I study what genomic conflicts have in common with other examples of conflict, whether spread of cancer cells, conflicts between worker ants over reproduction, or between the microbiome and its host organism. Together with Kevin Foster (University of Oxford) I develop mathematical models connecting selfish genetic elements to general models of social evolution. With Nick Davis (LSHTM), we recently published a first manuscript describing how enforcement, mechanisms that suppress selfish behaviour, is an underappreciated, and often critical, ingredient for cooperation at all levels of life – from genomes, eukaryotic cells and multicellular organisms to societies and mutualisms between species.
The history of the gene’s-eye view of evolution
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 and here).