Tag Archive for 'Last Eukaryotic Common Ancestor' | Sci.News

Eukaryotic life appears to have flourished surprisingly late in the history of Earth. This view is based on the low diversity of diagnostic eukaryotic fossils in marine sediments of mid-Proterozoic age (around 1.6 billion to 800 million years ago) and an absence of steranes, the molecular fossils of eukaryotic membrane sterols. This scarcity of eukaryotic remains is difficult to reconcile with molecular clocks that suggest that LECA had already emerged between around 1.2 and more than 1.8 billion years ago. LECA, in turn, must have been preceded by stem-group eukaryotic forms by several hundred million years. Brocks et al. report the discovery of abundant protosteroids in sedimentary rocks of mid-Proterozoic age. Image credit: Arek Socha.

Molecular Remains of Ancient Complex Life Found in 1.6-Billion-Year-Old Rocks

Jun 8, 2023 by Enrico de Lazaro

Paleontologists have detected abundant protosteroids — traces of ancient life forms — in 1.6-billion-year-old sedimentary rocks that had formed...