India, Oct. 25 -- It started quietly; with single cells dividing in the dark.

From that microscopic revolution came multicellular life; the strange Cambrian creatures that once ruled the seas; the fish that crept onto land; early reptiles; furry mammals that scurried beneath dinosaurs; apes, elephants, whales, giraffes, humans.

We may never have a complete map of exactly what goes where, on the grand, sprawling expanse that is this "tree of life".

There have been times when we weren't even sure it was a single tree. But data shows it is. And now, we're parsing information in milliseconds, building branches armed with more information on a single species than entire libraries contained just two centuries ago.

Max Telford represents the...