Could we create life, and if we did, would it have to be life as we know it?
We always seem to assume that if we ever find life on another planet (or it finds us!), it will be some variation of an earth creature, and it might even have an American accent. It might be a monster, but it will probably have a head and legs and arms and eyes. It probably eats things, even if those things include us, and it probably communicates by vocalising. It has the same senses as us, detecting our visual spectrum, sensing changes in atmospheric pressure as we do using our ears, and detecting airborne molecules as earth creatures do, using their noses.
But as the old song says, it ain’t necessarily so. After all, just because a template for life evolves on one planet, who’s to say that a similar template will emerge elsewhere? Certainly, many creatures on this planet have a great deal in common. All the vertebrates share the same fundamental pattern, evolved from a common ancestor, as do all the insects, and if you go back to an even more remote ancestor, there’s still a significant amount in common between the insects and the vertebrates. Heads. Guts. Legs. Brains.
But of course, it didn’t have to be like that. Just as there’s a near-infinite number of planets, there’s also a near-infinite number of random solutions to the life problem.
Most estimates of the number of habitable planets in the universe are based on the assumption that life must be carbon-based, probably because, as humans, we try to project a human form onto the things we can’t imagine. We anthropomorphise everything – even our deities – because that’s our comfort zone, and it’s fair enough — there might even be a good evolutionary reason why we do so, although I have no idea what that reason might be.
One way or another, though, we’re wrong, and not only wrong, but arrogant as well. Who knew humans could be arrogant? After all, if life doesn’t have to be carbon-based, who’s to say that our neighbouring planets are too hot or too cold, too dry or too poisonous? We don’t know what inorganic life survives on, so we can’t say where it might live.
It’s true that organic compounds lend themselves to building the elements of life because of the properties of carbon – especially its ability to form long and complex chains of molecules, but scientists have been examining other ways of creating cell-like, self-replicating biological structures, and it turns out that carbon isn’t essential. They can create lifelike cells using many other elements, and those cells will have the ability to divide, replicate and even more surprisingly, compete for dominance. Evolution in a bottle.
I came across an interesting lecture on ted.com recently, delivered by scientist Lee Cronin. In his lecture, Cronin makes many interesting points, but probably the most thought-provoking is when he asks if life is really that improbable. Is it so very unlikely that life will spontaneously emerge, as it did on Earth? His answer is even more startling: the emergence of the first cell is as probable as the emergence of the stars. If the physics of fusion is encoded into the universe, he suggests, then the physics of life is as well. Or to put it another way, not only is life likely to emerge: it must.
Cronin and his team have been building complex inorganic structures that display the very same characteristics as DNA. They’ve created cells like any bacterium, but with a nucleus that contains no carbon. Inorganic life, in other words.
So where does this stop?
The answer is that it doesn’t.
Do you remember Stephen Hawking’s plea to stop sending pictures into space and recordings of Beethoven’s Fifth? Stop, he said, or they’ll come and kill us, and he was right. Whatever comes out of the void will have no interest whatever in us, any more than Cortes the Killer gave a fig for the welfare of the native South Americans he robbed and slaughtered. Probably much less, since at least the Indians looked much like their European oppressors and might have evoked some kind of empathy as fellow humans.
What will come out of the void to oppress us?
Who can say?
In the best of cases, we can imagine a creature evolved beyond all physical cares, coming with nothing more than a desire to learn.
In the worst case, what we’ll get is a thing that we don’t recognise as life, and that in turn doesn’t recognise us. It wants what we have: our air, our water or perhaps the core of our planet and it cares nothing for our existence because it doesn’t even know that we live, nor does it care.
I know. You don’t have to laugh. I’m doing it already. It’s life, Jim, but not as we know it.
Of course, since we have no idea what a life form looks like, we can hardly identify it even if we see it, so what about the possibility that such life exists not only on Mars and Venus, Jupiter and Saturn, but also here on Earth?
Until Lee Cronin finishes his research, we can’t discount the possibility that the entire planet is a living creature, and that we humans are little more than the fleas that make it itch.