Tuesday, December 11, 2007

Is Death Coded In Our DNA?

Have you ever wondered if death might be a beneficial thing, in terms of human evolution? I’m not talking about destroying the species, I’m talking about the idea that there is a beneficial side to members of the species dying at prescribed times. If that’s true, is death encoded in our genes?

This sounds really morbid, I know. Maybe it is.

Let me tell you what got me thinking about it, though.

Lately I’ve been seeing different reports about how the human lifespan is increasing. You’d think that this would be the goal with evolution. Long life = healthy species. But, we’ve also been seeing more degenerative diseases cropping up in our society than we ever had before. Some are speculating it’s because we’re living longer than we used to. People of earlier generations just didn’t live long enough to develop them.

I’ve also been thinking about the problems with cloning. The cells used to clone animals seem to know how old they are. The clones develop diseases comparable to the older animals and die earlier than they should.

It makes sense. Some have speculated that aging is simply the result of mistakes cropping in from time to time within our DNA when cells replicate, especially in the mitochondria. Cells are pretty good at catching those mistakes, but it’s not a perfect system.

Now let’s look at forest fires. It turns out that forest fires may not be all that bad for the plants in the forests. Destroying old growth makes room for the new growth that lives below the vertical fire line. They’d be choked out by the older growth, otherwise.

This isn’t a great example, because it’s environmental, but stay with me.

The same hold true with animals. When older animals die, or herds are thinned by predators, there’s less competition for resources. The younger ones have a better chance for survival.

Anything that codes for a mutation in a species’ genome, that allows it to adapt to changing conditions and survive while others die, allows that mutation to be passed on to it’s children. It creates a stronger creature that is better “fit” for survival. If death allows for the younger, stronger creatures to more easily survive, could death be an adaptation that is actually coded in our genome as a tool for survival?

It seems contradictory, I know. But, what if it’s not? Does that mean that our efforts to prolong the lifespan of those who are genetically damaged, or otherwise have been “selected for death,” run counter to evolutionary progress as a species?

The social ramifications of this, if it’s right, are frightening. I can easily imagine the potential horror of governmental policies that could be developed around this idea. Children that are “imperfect” would be left to die. Adults that are “imperfect” could be left to die. Their contributions to our society would be lost. If you really wanted to “go down the rabbit hole” with this, it could lead to a “Logan’s Run” or “Brave New Word” scenario, where "undesirables" aren’t just allowed to die, they are actively killed.

And all by government mandate.

Sometimes I scare myself.

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