Humans and other animals with brains perhaps aren't the only beings on the planet to experience consciousness, says a study in the journal EMBO Reports.

Conventional thinking about consciousness—called the standard model of consciousness—focuses on the brain, supposing only complex organisms like humans and animals have it. But the new cell-based theory argues that consciousness started with the very first cells that emerged about 3.8 billion years ago and plants, bacteria and even amoebas have it.

The cell-based theory could potentially reframe how we view life, intelligence, and even artificial intelligence, challenging what we already think about existence.