40,000-year-old footprint of first Americans

A plastic replica of a 40,000-year-old, size eight foot has shattered previous theories of the identity of the first humans to walk in the Americas.

Scientists made the foot from tracks left on the shore of an ancient volcanic lake in central Mexico.

The traditional view is that the first settlers walked across the Bering Strait, from Russia to Alaska, at the end of the last ice age around 11,500 to 11,000 years ago.

But the discovery of footprints in the Valsequillo Basin by a British-led team provides new evidence that humans settled in the Americas as early as 40,000 years ago, suggesting that there were several migration waves at different times by different groups.