Biodemography is a new branch of human demography concerned with understanding the complementary biological and demographic determinants of and interactions between the birth and death processes that shape individuals, cohorts and populations. It is a way of thinking of demographic processes and outcomes that synthesizes insights from biology and biomedicine at molecular to physiological, individual to kin, and population to evolutionary levels. The ability of scientists to conduct biodemographic studies depends not only on merging theoretical and methodological elements from the biological and demographic/actuarial sciences, but unique sources of data and statistical methods must also be developed.