According to an alternative model of how intelligent life emerges on planets like Earth, the existence of aliens—and human beings–could be the result of natural planetary processes.

Scientists challenge the idea that intelligent life is rare. They argue that evolution follows planetary changes, not random luck.

For decades, scientists have debated whether humanity’s existence is a rare cosmic accident or the natural outcome of planetary evolution. A new study challenges long-standing assumptions, suggesting that intelligent life may be an expected result of planetary development rather than an improbable occurrence.

For decades, scientists assumed that life on Earth emerged through a chain of highly improbable flukes. But a new theory suggests it may have instead arrived just in time.