UIC EXPERT TINKERS WITH EVOLUTION TO CREATE 'BUILT-TO-LAST' HUMAN
If humans were designed to live beyond age 100 and remain free of many of the diseases and disorders associated with aging, we might have looked like short, stout elves.
This conclusion may be drawn from illustrations that accompany the article, "If Humans Were Built to Last," by UIC Professor S. Jay Olshansky and his colleagues in the March 2001 issue of the magazine Scientific American.
Our bodies evolved to survive long enough to reproduce and raise our young, says Olshansky, professor of biostatistics in the UIC School of Public Health and noted demographer of aging. Human ingenuity has made it possible for us to extend our lives well past our reproductive years.
"Had our bodies been crafted for extended operation, we would have fewer flaws capable of making us miserable in our later days," he writes. "Evolution does not work that way. Instead, it cobbles together new features by tinkering with existing ones in a way that would have made Rube Goldberg proud."
The article, written with Bruce Carnes, senior research scientist at the National Opinion Research Center at the University of Chicago, and Dr. Robert Butler, president of the International Longevity Center in New York City, outlines design "flaws" that lead to bodily malfunctions as we age, and the hypothetical, evolutionary design "fixes" that would allow us to enjoy good health well into our postreproductive years.
"Humans can live for a long period of time in good health because the harsh environments of our ancestors forged a human-body design that is robust," said Carnes. "But the seeds of self-destruction sown at conception become more obvious with the passage of time."
The article includes illustrations of what humans might look like if we were designed for health and longevity. For example, some of the extended-use features might include rewired eyes, bigger ears that are mobile, a curved neck, forward-tilting upper torso, extra-padded joints, larger bones and muscles, shorter limbs and stature and backward-bending knees. Walking upright probably contributed to human intelligence and an expanded foraging range, the authors note, but at the price of aging-related disorders, including slipped disks, lower back pain, varicose veins and worn-out joints.
Where our heads are concerned, the authors cite the weak link between the optic nerve and retina, which is prone to detaching after decades of use, fragile hair cells in our ears leading to hearing loss, and a common passageway for food and air, raising the risk of inhaling food or drink as muscle tone decreases with age.
Then, there are what the authors refer to as "plumbing problems." In males, these problems include a urethra prone to constriction by an enlarged prostate that may obstruct the flow of urine, and in females, bladder and pelvic-floor muscles and ligaments that weaken with time and multiple pregnancies, which may lead to incontinence.
Emphasizing the positive message of the article, Butler observes, "Despite the limitations and flaws about which we write, there is so much power we as individuals have to maintain our health. Through good health habits and modern medical interventions, we have an opportunity to, as the Greek lyric poet Pindar said, exhaust the limits of the possible."
Olshansky and his colleagues contributed to the development of a paradigm for understanding mortality known as biodemography. This approach to human aging and longevity, as well as age patterns of death across species draws on the disciplines of demography, epidemiology, evolutionary biology, molecular biology and anthropology.
Olshansky is the author with Carnes of the new book, "The Quest for Immortality: Science at the Frontiers of Aging," published by Norton.
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