Image: Vinoth Chandar, Flickr, Creative Commons.

In nature, there are numerous species that die immediately after reproducing, like the female octopus. Others, like the alligator, may not age at all. So what do they have in common? They're evidence that aging may not be an inherent trait, but a product of how species evolve in given environments—and that evolution may actually be programming species, including humans, to die.

The tantalizing prospect is the subject of a new study, "Programmed death is favored by natural selection in spatial systems," from some top flight complex systems researchers and biologists. They've used a brand new mathematical model to flip the traditional understanding of the aging process nearly on its head. If its results prove accurate, it would have massive ramifications for how we understand the process of aging itself—and may lend hope to those seeking to reprogram humans to live even longer.

The bound-to-be controversial idea is being put forward by Yaneer Bar-Yam, the head of the New England Complex Systems Institute (NECSI), Donald E. Ingber, the founding director of the Harvard Wyss Institute for Biologically Inspired Engineering, and Justin Werfel, a researcher affiliated with both. The team's new work has been published in the Physical Review of Letters, and it argues that the "mathematics underpinning our understanding of evolution is fundamentally flawed."

Right now, we assume that evolution is naturally selecting for organisms with longer lifespans—giving them a better chance to survive, right?

"In traditional theory, evolution will always choose the longest lifespan, and then what we experience is the longest possible, biologically," Bar-Yam told me in a recent interview. "We can shorten it, we cannot lengthen it."

But what if creatures' lifespans—including humans'—weren't necessarily determined by their bodies' adeptness at staying alive, but regulated by evolution, based on the amount of resources available to a given population, and its members' pressures to reproduce? What if death wasn't a foregone conclusion, but rather a sort of measure instituted to ensure a single generation wouldn't suck down all the resources and doom the next? That's the team's findings, stated very basically.

"If evolution is determining the lifespan that we have, then we can choose to change that, by intervening in the mechanism that is being used to control our lifespans," Bar-Yam said. His works cites the host of creatures whose bodies behave starkly against their own self interest as evidence that death is evolutionary regulated, not inherent.

"Aging is not inherent. It's genetic. The prospect of extending lifespans dramatically is a reasonable conclusion."

"For example, there's an octopus that lives until it reproduces then it dies," he tells me. "But if you remove its gland it will continue to live, and that death is being triggered by the system as opposed to an inherent breakdown."

"Crocodiles," he continues. "As far as we know, they don't age. There are animals that have wildly varying lifespans in relation to each other. Rockfish—some of them live a few years, and some of them live hundreds of years." Bar-Yam sent me a graph of the different Rockfish species, and they live for radically different lifespans, despite remarkable genetic similarities.

Rockfish lifespans. Cailliet et al, Experimental Gerontology, 36, 739 (2001)


All this, he says, is evidence that aging is not inherent, but a baked-in evolutionary tic.

So how did the researchers get there? Why had the previous mathematical model used to describe evolution come to such a radically different conclusion?

"That traditional evolutionary theory works with an assumption where every organism is in the same environment," Bar-Yam said. "You can call it an averaging approximation. In physics, it's called the 'mean field approximation,' and it basically ignores the local context. One of the core things that we've done is point out that when local context is included in the theory, what you end up having is a feedback property between the organism and the environment, and the organism's properties change the environment, and that changes the outcome."

Team Harvard + NECSI employed a new, and, they believe, more accurate model for how organisms interact with the local resources they depend upon for survival, over time.

The result is fascinating: "We find that spatial heterogeneity of limiting resources and self-organizing population structures result in robust selection for lifespan limitation," they write in the paper. In other words: combine limited resources and fierce competition in a given region with a population fighting for survival, and it results in shorter lifespans. "In our model, intrinsic mortality leaves resources for descendants, which are more likely to be found in the