"Water, the Essence of Life"
Last updated
Was this helpful?
Last updated
Was this helpful?
I'm Timothy Allen, a theoretical biologist who studies complexity, though I was originally trained as a botanist. Botanists study seeds and sperm floating in water and things like that. Let me paint you a picture: imagine a pine seed, which is a gymnosperm, and the sperm comes down through a little hole and is injected into its own private swimming pool. It swims around there for about six months while the egg inside gets ready, and then their sexual fusion occurs. It really does swim - it looks like a little plankton cell. You can think of it as a plankton cell that's brought its own ocean with it.
If you extend that to us, the concentration of various solutes in our bodies is quite close to sea water. Maybe we are a bunch of zooplankton who've brought their ocean with them. But it's even more radical than that. We always think of life as being carbon-based - so is my brain carbon-based life? Well, 80-90 percent of it is water. Maybe we're missing the point. In fact, living systems are all colloidal, and the colloidal base is water with various things floating around with electric charges in them. When you die, your chemistry stays the same, but you start leaking. That's what happens immediately, and the reason is the water has lost control - you've curdled.
When we think of life, we normally think of success in terms of fitness or growth or increased numbers. Those are all very carbon-based ideas. But what about the concept of work? I would say that a living system is doing better if it's getting more work done. The trouble is, photosynthesis doesn't provide enough energy to do enough work. Most of the work that's done in an ecological system with plants in it is done by the latent heat of vaporization of water.
I've done some experiments on this too. We've found plants which are more effective, and as they become more effective, their upper surface gets cooler because they're evaporating more water. If you get a hold of a couple of coke bottles and put them together, and the flow goes down, you get this whirlpool. Well, the gradient for life, I think, is warm planet, cold outer space, and what we do is to shorten that gradient, grab hold of the heat of the planet and turn it into work.
In a certain sense then, you don't have any life on Mars because there isn't any water to get organized. You see, it's water that's the organizing factor here. Think of a tree as a device for moving water. In a sense, it's not that the carbon is in control - looking at it this way, it's really that a tree is water's device of interfacing between soil and air. Without a tree, you can only interface the topmost centimeter, but with a tree, you can in fact go down a whole meter or so.
So water is what life is about; carbon is something it uses. It just uses that thermodynamic gradient. Remember I said that we might be zooplankton that have brought their ocean with us? No - we're not. We're some ocean that's brought its zooplankton with it. You're mostly water. Water's in control of life.