<p>To learn about the first organisms on our planet, researchers have to analyse the rocks of the early Earth. These can only be found in a few places on the surface of the Earth. The Pilbara Craton in Western Australia is one of these rare sites: there are rocks there that are around 3.5 billion years old containing traces of the microorganisms that lived at that time. A research team led by the University of Göttingen has now found new clues about the formation and composition of this ancient biomass, providing insights into the earliest ecosystems on Earth. The results were published in the journal <em>Precambrian Research</em>.</p>