Age and origin of Earth’s early fossils questioned

Microstructures in ancient titanite found in South Africa were thought to be among the oldest traces of life on Earth. The minerals are younger than previously thought and the microstructures don't quite match what early microorganisms might have left behind, a new study suggests.

Courtesy of E. Grosch/Univ. of Bergen

Some of Earth’s earliest life-forms were thought to have left their mark roughly 3.45 billion years ago in minerals found in what is now the Barberton greenstone belt of South Africa. However, the minerals formed closer to 2.9 billion years ago, and the microstructures within them were not created by early microorganisms, scientists argue May 26 in the Proceedings of the National Academy of Sciences. The results suggest that scientists will have to search for a different set of signatures of early life on Earth and also on other planets.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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