Life’s early traces

New finds help push microbe origins beyond 3.5 billion years ago

FIRST TRACES  The Pilbara region in Western Australia, home to Millstream Chichester National Park, may hold signs of the planet’s earliest complex life. 

Peter Hendrie/Getty Images

Western Australia’s Pilbara region isn’t known for its hospitality to life. Dry creek beds carve paths through dusty red earth, and razor-sharp grasses cover the area’s low hills.