In the article titled, “Longevity Among Hunter- Gatherers: A Cross-Cultural Examination”, by Michael Gurven and Hillar Kaplan, the authors find that survival of Homo sapiens has gradually increased and people who lived before us, has a shorter life span than people of the current time. The longevity in this article is described as senescence-associated age of death. If human lifespan is divided into three phases: childhood, adulthood and older adult (after 40 years of age), mortality rates are higher among older adults. Lifestyle changes and better sanitation practices have helped to reduce mortality rates across all three phases of lifespan. Through their study in hunters and horticulturist, the authors conclude that there is a nonlinear increase in mortality associated with senescence in both the groups. The study also suggests that senescence could be an endogenous trigger for mortality. (Gurven & Kaplan, 2007) David Troyansky, in his article titled, “Aging in World History”, provides the readers a perceptive on how people age across the globe. His work provides insight on how differences in individual traits, demography, culture, social welfare programs, and ethnicity, affect lifespan. Different anthropologists have different views about aging, while some consider the chronological age of 60 -65 years to define the onset of aging, others consider 30 years of age to define the aging process. As the human age advances, a number of physical changes occur in the human body, and at a very later age in life, these changes shift from regulation to dysregulation of the body. The capacity of the individual to function decreases in old age and this is associated with senescence. Maximum somatic capacity in most people is achieved by the age of 30 and beyond this age, there is no appreciable development. Adipose deposition in the body increases after 30 years of age in most adults and decreases in senescence. (Schweitzer, 1991)
References
Gurven, M. & Kaplan, H. (2007). Longevity Among Hunter- Gatherers: A Cross-Cultural Examination. Population and Development Review, 33(2), 321-365. http://dx.doi.org/10.1111/j.1728-4457.2007.00171.x
Schweitzer, M. (1991). Anthropology of aging (1st ed.). New York: Greenwood Press.
