Levente Szabo
SOME 4 billion years ago, somewhere in the mass of inert minerals and molecules that made up our wet, rocky planet, dead became alive. This was the most important chemical transformation ever to happen on Earth. Not only did it give rise to all the living things that have ever existed, it also altered the chemistry of the oceans, the land and the atmosphere above. If it hadn’t happened, there would be no blue marble.
That first chemical step towards life may be a lot closer than we thought. Buried within every cell of every organism on the planet, from bacteria to barnacles to Britons, is a living, working version of the earliest life on Earth – a time machine that allows us to peel away those 4 billion years of history and work out how it all began. “We can stop bullshitting about the origin of life,” says Loren Williams, a biochemist at the Georgia Institute of Technology in Atlanta. “We can see it.” What he and his colleagues are discovering is turning our view of life’s origins on its head.
Until now, most efforts to understand how life began have attacked the problem from the bottom up. Broadly, they start with an experimental soup of primordial molecules and try to either recreate the building blocks of genes or get them to evolve key functions, like self-replication. Despite some promising results, these approaches can at best show a plausible path that life might have followed. They can never reveal what actually happened.
The new approach starts with modern life and works backwards. Formed of a tangle of proteins and a …
