The earliest known #eukaryotes, the ancestors of all complex #life on Earth, lived in oxygenated, shallow marine environments nearly 1.7 billion years ago. The earliest eukaryotes for which we have #fossils lived in predominantly near-shore, oxygenated, benthic (on the seafloor) settings. This implies that the availability of #oxygen was dictating eukaryote #evolution from its early stages. #biology #astrobiology https://astrobiology.com/2026/05/early-complex-life-lived-in-oxygenated-seas-challenging-long-held-views-of-evolution.html Paper by Lechte et al. (2026): https://www.nature.com/articles/s41586-026-10533-4