Scientists just found out that mortality is an evolutionary trait

[DetlefK]

http://io9.com/are-limited-lifespans-an-evolutionary-adaptation-1710634703

"By running variations of their model hundreds of thousands of times, a research team led by Yaneer Bar-Yam from the New England Complex Systems Institute (NECSI), in collaboration with the Harvard Wyss Institute for Biologically Inspired Engineering, observed that evolution favors shorter lifespans in environments where resources are scarce and when pressures to procreate are particularly intense. The simulations appeared to show that lifespans of animals — humans included — are genetically conditioned, and not the result of gradual wear-and-tear."

...

"Bar-Yam and his team reached this conclusion by developing a simple model that analyzed how the lifespans of simulated organisms would change and evolve over time under spatially constrained conditions.

Instead of looking at the average conditions of environments over time, this model took local variations into account in environments where organisms evolve. In their simulations, the researchers used cellular automata to observe the evolution of lifespan limits and the onset of intrinsic mortality. Though the simulation took place within a tight spatial system, some variables were adjusted, including the presence of self-renewing resources (which in a real life scenario would be akin to the re-growth of grass for grazing animals, available fish stock for dolphins, and so on).

“We simply designed an understanding of what happens when we don’t make the assumption of the same environment,” Bar-Yam told io9. “The only thing it relies upon is spatial locality, which, along with resource limitation, is generally the case in nature.”

Fascinatingly, group selection — the idea that natural selection acts at the group level — was never a consideration in the model. Yet the simulations consistently showed that a built-in life expectancy emerged among the simulated organisms to preserve the integrity of their species over time. This is surprising because a pro-group result was produced via an individualized selectional process."

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Translation:
They created a very general simulation of life-forms in an environment with regenerating, depletable ressources. Immortal life-forms that could produce offspring. Over time, the life-forms developed a limited life-span (mortality) to make sure that the old life-forms don't use up the ressources that are better spent on the offspring.

The scientists postulate that life-span is determined by the genes (the software), not the body itself (the hardware), and can therefore be manipulated.





This begs the question: If mortality is an evolutionary adaption to optimize population-control and ressource-management, wouldn't increasing our life-spans reduce the overall viability of our species?

Example:
A simple genetic manipulation can increase the life-span of a nematode-worm five-fold.
There are currently 7 billion homo sapiens on this planet and they get up to 100 years old.
If you double the life-expectancy to 200 years, we would have a much larger population at a given time because there simply would be way, way more old people around.

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Another implication:
If mortality is genetic, this means there is a probability for some life-form to develop a mutation that shuts off the life-span limiters.
Barring a violent death, this life-form, this person, would simply fail to die.
Death by old age would be something that this body would simply be unable to... do.

[itsrobert]

1. New retirement age: 175 years old

Rand Paul is writing the bill as we speak.

[Lemonwurst]

2. Fascinating, but...

... I assume all physical entities would have a "best case scenario" lifespan that only decreases based on environment conditions, including this kind of learned evolution response.

Still, this is great fodder for redefining any species' lifespans, including humans. A great premise for a sci-fi story, to be sure, but also a goal in its own right. For instance, consider our average human life expectancy just 100 years ago.

[DetlefK]

3. You have to use maximum life-span, not average life-span.

In the Stone-Age people grew on average to 20-30 years, but that was due to high child-mortality. The maximum life-span was more like 60 years.

I believe that the biggest increase in life-expectancy is due to medical efforts to prolong life until the highest possible life-span is actually reached.

[qazplm]

4. I firmly believe

humans one day will live to be 200, 300 or even longer.

Unfortunately for me, probably not any day I'll see, but I think perhaps someone alive today will see it albeit they may be a toddler at this point.