New finds help push microbe origins beyond 3.5 billion years ago
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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. In this place with record-setting heat and months of minimal rainfall, hardy plants and animals eke out an existence.
But the Pilbara may have been prime real estate for the planet’s earliest complex life-forms. In the region’s 3.5-billion-year-old rocks, geobiologist Nora Noffke has found tiny, subtle patterns that may reflect communities of microorganisms. The patterns look just like those made by moist mats of microbes found along today’s shorelines. The markings Noffke spotted in Australia may be the earliest evidence of complex life on Earth.
Other scientists aren’t so sure. Early signs of life are hard to interpret, and are famous for stirring up controversy. Taken one at a time, every odd