March 13 2000  UNITED STATES
Meteors provided boost to evolution

BY ELIZABETH JUDGE
A METEOR STORM four billion years ago may have seeded the Earth with organic
molecules that helped life to develop, while another storm 500 million years
ago may have prompted the rapid growth in the variety of species known as the
Cambrian Explosion, scientists have concluded.
Richard Muller, professor of physics at the University of California,
Berkeley, and colleagues reached that conclusion after examination of glass
"beads" from the Moon, brought back by the Apollo 14 astronauts. The remnants
of the impact of the storms on the Moon, their age was determined through
examination of their potassium content. The research work was reported in the
journal Science.

Professor Paul Renne, a member of the University of California team at
Berkeley, said: "Maybe life began on Earth many times, but the meteors only
stopping wiping it out about three billion years ago."

Professor Muller said of the Cambrian storm: "Although most people assume
that impacts cause death and destruction, it is possible that the additional
stress forced life to become more diverse and flex-ible." Most of the major
animal groups emerged during the Cambrian Explosion.
www.aas.org/
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