The fundamental structure of human populations has changed exactly twice in evolutionary history. The second time was in the past 150 years, when the average lifespan doubled in most parts of the world. The first time was in the Paleolithic, probably around 30,000 years ago. That’s when old people were basically invented.
Throughout hominid history, it was exceedingly rare for individuals to live more than 30 years. Paleoanthropologists can examine teeth to estimate how old a hominid was when it died, based on which teeth are erupted, how worn down they are, and the amount of a tissue called dentin. Anthropologist Rachel Caspari of Central Michigan University used teeth to identify the ratio of old to young people in Australopithecenes from 3 million to 1.5 million years ago, early Homo species from 2 million to 500,000 years ago, and Neanderthals from 130,000 years ago. Old people—old here means older than 30 (sorry)—were a vanishingly small part of the population. When she looked at modern humans from the Upper Paleolithic, about 30,000 years ago, though, she found the ratio reversed—there were twice as many adults who died after age 30 as those who died young.
Excerpt from an article written by Laura Helmuth at Slate. Continue THERE
The signal public health achievement of the 20th century was the increase of the average human life span. Now, as that achievement helps raise the proportion of the aged around the world, what once seemed an unalloyed blessing is too often regarded as a burden — a financial burden, a health care burden, even a social burden.
“It’s nuts,” said Dr. Linda P. Fried, an epidemiologist and geriatrician who is dean of the Mailman School of Public Health at Columbia University. “To assume defeat from what every one of us as individuals wants suggests we’re not asking the right questions.”
Findings from the science of aging, Dr. Fried said, should “reframe our understanding of the benefits and costs of aging.”
From her perch at Mailman, a position she has held for four years, Dr. Fried is pushing students, professors and a wider audience to ask the right questions and ponder the right policies for coping with an aging world population.
Dr. Fried’s mandate is to lead a school that will give a new generation the tools to deal with global challenges to public health, including environmental degradation, climbing health care costs and the pressure of rapid urbanization. But she believes that research on aging and health changes “across the life course” are central to designing solutions to public health problems in the 21st century.
Excerpt of an article written by KAREN PENNAR, NYT. Continue HERE