Curiosity Stream

Human By Chance?

95% loved this4KCC
Plans start at $4.17/month

A single genetic twist may have reshaped the human brain.

This documentary examines how a rapid expansion of the brain, beginning about 2 million years ago, helped humans become Earth’s predominant species. Following research into the cerebral cortex and a possible role for a single genetic change, it challenges the idea that human evolution was inevitable. Sign up to watch a provocative, evidence-driven look at what made us human.

Love Human By Chance?? It’s just the start.

Join now to unlock the whole library — thousands of award-winning documentaries beyond Human By Chance?, from the deep ocean to deep space.

  • New shows weekly
  • Exclusive originals
  • Watch anywhere
  • No commitment

Pick the plan that’s right for you.

Flexible plans, no contracts.

Thousands of documentaries across nature, history, space, and science.

  • Watch in 4K on all your devices
  • Download and watch offline
  • Stream ad-free — cancel anytime
Cancel anytime, on either plan.

Thousands of documentaries across nature, history, space, and science.

  • Up to 4K
  • Offline downloads
  • Ad-free

Frequently asked questions

Got your answer? Pick a plan and start streaming.