RT Journal Article SR Electronic T1 Darwinism JF Journal of Epidemiology and Community Health JO J Epidemiol Community Health FD BMJ Publishing Group Ltd SP 973 OP 973 DO 10.1136/jech.2009.095372 VO 63 IS 12 YR 2009 UL http://jech.bmj.com/content/63/12/973.abstract AB