1. Department of AnthropologyNorthwestern University 1810 Hinman Avenue Evanston IL 60208 USA
2. McGill Center for the Study of Complex Traits, Department of Human Genetics, Department of BiochemistryMcGill University 3649 Sir William Osler Promenade Montreal QC H3G 0B1 Canada
3. Department of AnthropologyMcMaster University 1280 Main Street West Hamilton ON L8S 4M4 Canada
4. Department of BiochemistryMcGill University 3649 Sir William Osler Promenade Montreal QC H3G 0B1 Canada