Evidence of life in Earth's oldest rocks

Abstract

Did life on this planet begin only after a relatively long planetary evolution, until suitable environments emerged that allowed life to gain a toehold, or was the cradle of life ready and rocking when Earth itself was but an infant? An answer may come from a paper on page 535 by Nutman et al.1 that analysed 3.7-billion-year-old rocks in the Isua Greenstone Belt in Greenland.