The origin of life • 30 September 2007 • The SnowBlog
The origin of life
Time for more you-heard-it-here-first, gee-whiz science. Unlike the linguistic divergence thing (remember that? No? OK, never mind) this one isn't mine. It's probably the idea of Thomas Gold, late of Cornell University. You were taught in school, those of you who attended one, that life originated on Earth in little gloopy pools of water, with lightning playing in the distance. But more recently it's been discovered that the microbes which live under the sea, in the boiling water of volcanic vents, are older than anything else on Earth. So now some people wonder whether life originated there instead and gradually spread out and reached the surface.
But a better theory is that life originated far underground. You see photosynthesis is difficult. And these volcanic vents, known as 'black smokers', are hostile places. What life needed to get it going was a stable, safe, unchanging environment where it could perfect the basic processes of growth, replication, feeding and repair. What a very few people believe, and I agree with them, is that life started aeons ago in the airless depths, powering itself using simple chemical reactions. Eventually it proved resilient enough to emerge and flourish in the caustic cauldron of volcanic vents. And from there it could gradually adapt and spread into the ocean, before eventually mastering the trick of photosynthesis and conquering the surface.
Weirdly there's a problem with that explanation and it's a problem that, unless you're a geologist, you'll probably never guess. The problem is that the earliest lifeforms would have needed a supply of raw materials to construct themselves from including long-chain carbon compounds, like the sorts of things found in oil. But oil, natural gas, coal - everything like that - as you'll also know if you went to school, is made from the remains of living creatures, so it couldn't have been around to help life get started. Or could it? For the answer to that conundrum tune in to the next instalment of Rob's Big Hokey Science Jamboree.