The origin of complex organisms called eukaryotes—which includes all animals, plants, and fungi—is one of biology’s biggest mysteries. A new discovery helps reveal these evolutionary roots.

The findings show that Earth's severe Cryogenian glaciations catalyzed a pivotal shift in the evolution and diversity of early eukaryotes during this eon, 2500 to 538 million years ago.

Biosignatures of diverse eukaryotic life from a Snowball Earth analogue environment in Antarctica. Nature Communications, 2025; 16 (1) DOI: 10.1038/s41467-025-60713-5 ...

In a new account of exquisitely preserved microfossils, researchers at UC Santa Barbara and McGill University revealed that eukaryotic organisms had already evolved into a diverse array of forms even ...

There are some "body" fossils of primitive eukaryotes dating back more than 1.6 billion years, but their scarcity compared to the plentiful bacterial remains from that time had suggested they were ...

Currently, the oldest unambiguous eukaryotic fossils are unicellular forms from late Paleoproterozoic sediments (~1.65 billion years ago) in Northern China and Northern Australia.