What was the force driving the evolution of life on earth? This
question, the answer to which has profound implications for our
world view, was neglected for most of the 20th century, not
because it was outside science, but because scientists didn’t
have the technical means to address it. Since the advent of
molecular biology, however, the question has become tractable —
and has been recast. The question now is about the origin of
cells — how did modern cells evolve? The orthodox Darwinian
model says that life began with one primordial cell. But this
week, Carl Woese, a microbiologist at the University of Illinois
at Urbana-Champaign, proposes a new theory. Instead of one
“mother cell,” there may initially have been three simple types
of loosely organized molecule groups. These protocells lived in
a kind of genetic commune, says Woese, a slime of RNA, where
genes — and hence new evolutionary tricks — could be shared
freely. The process is known as horizontal gene transfer. Whole
chunks of genetic material, RN