Digging into the 'deep history' of life (CNN)

(CNN) -- Unlike most budding paleontologists, Andrew Knoll's fascination
with fossils didn't lead him to dinosaurs. Instead, he focused on the first
stirrings of life -- the evolution of prehistoric bacteria.

"There are times when I wake up and wish I could find something as sexy as a
dinosaur," Knoll admitted. "On the other hand, what I'm trying to find out
is how the modern fabric of the world came to be and what was in place long
before the dinosaurs existed."

Sure, a brontosaurus is big, but a bacterium is better, according to Knoll.

"Bacteria forms the ecological microcircuitry of the Earth," he said. "All
of the great cycles of elements that sustain biology on this planet -- the
carbon cycle, cycles of sulfur and nitrogen and phosphorous -- have links in
that circuitry. The world would do just fine in terms of the persistence of
life without plants and animals, but if there were no bacteria, life on
Earth would stop in an instant."

The Harvard University researcher specializes in what he calls the "deep
history" of life, going far beyond the unfolding of animal diversity 550
million years ago known as the "Cambrian explosion."

"The evolutionary process really began with the origin of life, perhaps 4
billion years ago, and then continued with organisms whose size and shape
and complexity was similar to what we would recognize as bacteria today," he
explained.

"Over long periods of time, more complex cells arose. They then formed
multicellular consortia that ultimately became functioning animals with
tissues. We, along with everything else that's alive today, are the product
of this 4 billion years of evolutionary history."

More stories of these earliest life forms are embedded in rocks and
geological outcroppings, waiting discovery by scientists with the skill and
patience to interpret them, Knoll said.

"I find that just intoxicating," he added.

Many people, however, are more thrilled by "Jurassic Park III." It's
unlikely that the subject of Knoll's work ever will have a featured role in
a Steven Spielberg project.

"Bacteria just needs a better publicist," he said.

Oryginal: http://europe.cnn.com/SPECIALS/2001/americasbest/science.medicine/pro.aknoll.html

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