1. Phillips, P. C. The language of gene interaction. Genetics 149, 1167–1171 (1998).
2. Phillips, P. C., Otto, S. P. & Whitlock, M. C. in Epistasis and the Evolutionary Process (eds Wolf, J. D., Brodie, E. D., III & Wade, M. J.) 20–38 (Oxford Univ. Press, Oxford, 2000).
3. Malmberg, R. L. & Mauricio, R. QTL-based evidence for the role of epistasis in evolution. Genet. Res. 86, 89–95 (2005).
4. Otto, S. P. & Gerstein, A. C. Why have sex? The population genetics of sex and recombination. Biochem. Soc. Trans. 34, 519–522 (2006).
5. Weinreich, D. M., Watson, R. A. & Chao, L. Perspective: sign epistasis and genetic constraint on evolutionary trajectories. Evolution 59, 1165–1174 (2005).