Dec. 7, 2011
The first shot across the bow came in 2002, when Oxford paleontologist Martin Brasier challenged the authenticity of what were then widely regarded as the fossil remains of some of Earth’s first life-forms. In the bargain he took on one of paleobiology’s great lions, J. W. “Bill” Schopf of UCLA, who made that find and still defends it. “It was like tackling Jesus or Moses,” Brasier says.
Now Brasier has emptied his second barrel. In August he and David Wacey of the University of Western Australia staked their own claim to a candidate for the oldest known fossil: a set of Slinky-shaped cells found on an ancient beach in western Australia, just 20 miles from the site of Schopf’s discovery. Brasier asserts that his fossilized cells are the remains of primitive anaerobic bacteria that lived 3.4 billion years ago. Schopf’s samples, he believes, are just ancient, patterned rock, with no fossils at all.
Settling the debate matters a great deal. At its heart is one of the biggest questions in science: When and where did life begin? Brasier’s find suggests that life on Earth started not near some oceanic thermal vent but rather in a warm, oxygen-depleted bath near the surface. It also bolsters the case that there once was life on Mars.