This paper examines regional and temporal trends in mortality patterns among the Tsimane, a population of small-scale forager-horticulturalists in lowland Bolivia. We compare age-specific mortality in remote forest and riverine regions with that in more acculturated villages and examine mortality changes among all age groups over the past fifty years. Discretetime logistic regression is used to examine impacts of region, period, sex and age on mortality hazard. Villages in the remote forest and riverine regions show 2-4 times higher mortality rates from infancy until middle adulthood than in the acculturated region. While there was little change in mortality for most of the life course over the period 1950-89, overall life expectancy at birth improved by 8 years from 45 to 53 after 1990. In both periods, over half of all deaths were due to infectious disease, especially respiratory and gastrointestinal infections. Accidents and violence accounted for a quarter of all deaths. Unlike typical patterns described by epidemiologic transition theory, we find a much larger period reduction of death rates during middle and late adulthood than during infancy or childhood. In the remote villages, infant death rates changed little, whereas death rates among older adults decreased sharply. We hypothesize that this pattern is due to a combination of differential access to medical interventions, a continued lack of public health infrastructure and Tsimane cultural beliefs concerning sickness and dying.
3Neel and Weiss ' (1975) analysis of mortality patterns among the Yanomamo of Venezuela and Brazil was a bugle call to anthropologists to "produce comparable bodies of Furthermore, there are even fewer cases for which the mortality experience of middle-aged and older individuals living in remote subsistence-oriented populations is well documented. The lack of focused studies is due in part to problems of age-estimation and small sample sizes of older individuals. Many studies tend to cluster adults into large age categories such as 40+ or 50+. As a result, we know very little about the traditional human aging process and how it varies among societies.In a recent review of all available demographic data on mortality patterns among huntergatherers and forager horticulturalists, Gurven and Kaplan (2006) showed that prior to significant exposure to western medicine and public health, humans exhibit a characteristic mortality profile that differs dramatically from that of other non-human primates, including from our closest relative, the chimpanzee. We found that: 1) Post-reproductive longevity is a robust feature of hunter-gatherers and forager-horticulturalists, appearing to be a fundamental feature of the life-cycle of Homo sapiens. Survivorship to grandparental age is achieved by over two-thirds 4 of people who reach sexual maturity, and lasts for two decades, on average; 2) life expectancies for modern foraging, and presumably ancestral populations, are typically low due to high infant and child mortality but adult mort...