Making life

I’ve talked about synthetic biology here before, but only in the context of adding new functionality to organisms that are already alive. Science writer Carl Zimmer has written an article for the June 2004 issue of Discover magazine that addresses a far more ambitious approach to synthetic biology: synthesizing a new life form altogether. See
“What Came Before DNA?” at CarlZimmer.com.

Improbable as it sounds, researchers are attempting to bootstrap life using as a roadmap our best guess as to how life got started in the first place. The idea is that, before DNA was used to store genetic information, and before proteins were used to perform their enzymatic magic, RNA was able to fill both roles. This means that instead of having to account for the mysterious arrival of three different cooperating types of molecules (DNA, RNA, proteins), we have only to account for the mysterious arrival of RNA. This latter scenario is preferred by William of Ockham.

Starting with this concept, researchers have been systematically evolving RNA molecules to fill various roles required in a living organism, and they’re having remarkable success. Transfer RNA (tRNA) already has my vote as coolest molecule of all time. Add to that microRNA, siRNA, RNAi, and others and it’s a safe bet that a lot of biology in the next few years is going to revolve around this remarkable molecule. There’s a lot of life in the old girl yet.