Study finds early complex life lived in oxygenated seas, challenging long‑held views of evolution (opens in new tab)

The earliest known eukaryotes, the ancestors of all complex life on Earth, lived in oxygenated, shallow marine environments nearly 1.7 billion years ago, according to a new study led by researchers at McGill University and the University of California, Santa Barbara. The findings cast doubt on the long-held belief that early complex life emerged in oxygen-poor environments or floated freely in the open ocean. Eukaryotes include humans, plants, animals, fungi and many microscopic organisms. Kn...