What if our descendants no longer introduced themselves as Americans, Chinese, Brazilians, or Nigerians—but simply as humans from Earth?

For most of our history, we've divided ourselves by the color of our skin, the language we speak, the country we were born in, or the beliefs we inherited. Yet biology tells a very different story. Every person alive today can trace their maternal ancestry back to a single woman known as Mitochondrial Eve, who lived in Africa roughly 150,000 to 200,000 years ago. She wasn't the first woman, nor the only woman of her time. She was simply the ancestor whose maternal genetic line survived to every human alive today.