More complex forms of life took longer to evolve, with the first multicellular animals not appearing until about 600 million years ago. The evolution of multicellular life from simpler, unicellular microbes was a pivotal moment in the history of biology on Earth and has drastically reshaped the planet’s ecology.

Everything alive today descends from a cell that lived 4.2 billion years ago, just a few hundred million years after Earth formed, new research suggests.

A new study describing a microscopic, algalike fossil dating back more than 1.6 billion years supports the idea that one of the hallmarks of the complex life we see around us—multicellularity— is much older than previously thought.

Some have argued that 2-billion-year-old, coil-shaped fossils of what may be blue-green or green algae—found in the United States and Asia and dubbed Grypania spiralis—or 2.5-billion-year-old microscopic filaments recorded in South Africa represent the first true evidence of multicellular life. Other kinds of complex organisms don't show up ...

The evolution of multicellular organisms from their unicellular ancestors marks a major transition in the history of life on Earth 5,6,7. This transition was accompanied by fundamental ...