For decades, scientists have been trying to discover the evolutionary purpose of aging. Since all living organisms have full sets of DNA that are able to replicate over and over, it would seem to be evolutionary advantageous for us not to age and continue regenerating tissue forever.
“Since the early 1950s, evolutionary biologists have come up with a few explanations, all of which boil down to this: As we get older, our fertility declines and our probability of dying — by bus collision, sword fight, disease, whatever — increases,” writes National Geographic‘s Virginia Hughes. “That combination means that the genetic underpinnings of aging, whatever they are, don’t reveal themselves until after we reproduce. To use the lingo of evolutionary biology, they’re not subject to selective pressure. And that means that senescence, as W.D. Hamilton wrote in 1966, ‘is an inevitable outcome of evolution.’”
“Except when it’s not,” adds Hughes, pointing to a newly published paper comparing aging patterns of 46 different species. “Sure, some species are like us, with fertility waning and mortality skyrocketing over time. But lots of species show different patterns — bizarrely different.”
Read the full, original story: Why Do We Age? A 46-Species Comparison
Additional Resources:
- “Can we slow the effects of aging?” New York Times
- “Genetic clues in mammals could unlock secret to anti-aging,” Boston Globe
- “Genes shared by relatives influence brain aging,” Genetic Engineering and Biotechnology News
