I am interested in all sorts of biological questions from animal behavior to disease ecology.
Recently I have become very interested in the paradox of diseases. If infectious disease is usually
caused by organisms with very simple genomes consisting of relatively few genes, how can they
overwhelm the complex and redundant immune systems of vertebrates, such as humans? One
potential explanation is that genetically different disease organisms positively interact with each
other to increase their group-level reproduction, through a process we have dubbed "social
heterosis." In genetics, heterosis refers to hybrid vigor or the increased fitness due to
outbreeding, when lineages cross that combine fitness benefits in offspring that were previously
limited to each lineage. In social heterosis, different disease lineages interact as if they were
multiple chromosomes rather than competing genomes in a way that enhances the growth rate of
all. We tested this hypothesis by mathematically simulating HIV evolving with social heterosis
within a hypothetical infected human host. Our model successfully reproduced many observed in
vivo patterns of infection and transmission of HIV that previously seemed paradoxical and
inexplicable. A potential practical benefit of understanding a "social genome" model of disease-
host interaction is that our research could lead to novel approaches to the prevention and
management of HIV and perhaps a variety of other diseases.