…. People in the past were not all dead by 30. Ancient documents confirm this. In the 24th century B.C., the Egyptian Vizier Ptahhotep wrote verses about the disintegrations of old age. The ancient Greeks classed old age among the divine curses, and their tombstones attest to survival well past 80 years. Ancient artworks and figurines also depict elderly people: stooped, flabby, wrinkled.
This is not the only type of evidence, however. Studies on extant traditional people who live far away from modern medicines and markets, such as Tanzania’s Hadza or Brazil’s Xilixana Yanomami, have demonstrated that the most likely age at death is far higher than most people assume: It’s about 70 years old. One study found that although there are differences in rates of death in various populations and periods, especially with regard to violence, there is a remarkable similarity between the mortality profiles of various traditional peoples.
So it seems that humans evolved with a characteristic lifespan. Mortality rates in traditional populations are high during infancy, before decreasing sharply to remain constant till about 40 years, then mortality rises to peak at about 70. Most individuals remain healthy and vigorous right through their 60s or beyond, until senescence sets in, which is the physical decline where if one cause fails to kill, another will soon strike the mortal blow.
The whole thing is worth reading. Archaeologists figured out the ages of the ancients by digging out buried remains from ancient cemeteries.
And speaking of ancient cemeteries, one has recently been discovered on the shores of Lake Turkana in Kenya. According to the Independent:
Constructed near Lake Turkana by the simple herders that inhabited the region 5,000 years ago, the Lothagam North Pillar Site, a cavity in the ground was filled with the dead.
The ancient Kenyans then stacked stones and raised large pillars to place on top. Some of them appear to have been sourced from up to a kilometre away, archeologists said. This kind of monumental architecture has previously been associated with societies governed by strict hierarchies such as ancient Egypt.
The original paper on the Turkana discovery is available here. The paper argues that the cemetery represents monumentality absent a social hierarchy:
Lothagam North’s initial creation and final closure required heavy labor, but during the intervening decades or centuries people assembled for hundreds of mortuary rituals that may have involved little toil. This behavior is inconsistent with nascent elites consolidating authority via recurring large-scale construction initiatives. Communal values were emphasized by placing deceased of diverse ages and both sexes in a single location, without spatial or artifactual patterning that would suggest social hierarchies. Near-universal yet idiosyncratic ornamentation also argues against sequestration of resources by a social subset. Absent other evidence, Lothagam North provides an example of monumentality that is not demonstrably linked to the emergence of hierarchy, forcing us to consider other narratives of social change.