Can scientists pare down the layers of complexity to reveal the essence of life, the foundation on which biology is built?

That's what Craig Venter and his collaborators have attempted to do in a new study published this week in the journal Science. Venter's team painstakingly whittled down the genome of Mycoplasma mycoides, a bacterium that lives in cattle, to reveal a bare-bones set of genetic instructions capable of making life. The result is a tiny organism named syn3.0 that contains just 473 genes. (By comparison, E. coli has about 4,000 to 5,000 genes, and humans have roughly 20,000.)

Yet within those 473 genes lies a gaping hole. Scientists have little idea what roughly a third of them do. Rather than illuminating the essential components of life, syn3.0 has revealed how much we have left to learn about the very basics of biology.