For a long time, the White Sands of New Mexico has been a popular tourist attraction. Today, tourists flock to see the stunning views of pure gypsum dunes that stretch miles.
However, previous visitors had different goals. Homo sapiens arrived here thousands of years ago to hunt mammoths, giant sloths and other megafauna. They left evidence of their presence, which will be used to improve our understanding of planet's population.
Paleontologists published data last week in Science that suggested that White Sands was walked by men, women, and children more than 21,000 years ago. The team provided a date that was more than 6,000 years earlier than previous estimates of the earliest human appearances in America. Pontus Skoglund of the Crick Institute in London described the discovery as "absolutely groundbreaking."
It was believed that Siberian hunter/gatherers didn't cross the Bering Strait from Asia to reach America until around 15,000 years ago. This belief has been held for decades. It seems that humanity arrived earlier than we thought.
This evidence supports the reassessment that Homo sapiens' last great continental conquest is not based on bones or old stone tools, but rather ancient footprints found in White Sands. The footprints of humans who walked close to lakes left behind damp footprints, which hardened and were then covered in sand. These marks are scattered across the landscape in thousands.
Over the millennia, layers of ditchgrass seeds were also buried. Scientists were able to prove that the fossils of ditch grass seeds, which are carbon-dated, were found above and below the same set of footprints. This was long before the last ice age.
Most people have not been skeptical of claims that previous finds have indicated an early date for America's settlement. The footprints research, however, has been celebrated. These footprints provide compelling evidence for an early date of humanity's arrival in America, Spencer Lucas, a New Mexico Museum of Natural History and Science Palaeontologist, said to Nature. This is a major breakthrough.
It is not clear how humans got to New Mexico during the worst ice age. It was a difficult time, but it is possible that groups of hunter-gatherers crossed a corridor that divided the main ice sheet that covered North America at that time. They could have travelled southwards along America's west coast in boats or on the Kelp Highway.
Scientists stress that there's more to this fascinating research than just finding a new date for America's populating. These footprints in time can also reveal a lot about human behavior in general.
It was like parents standing at the school gates and talking to their children, but the children were running around the playground.
The issue of age of those who left footprints is a first. Professor Matthew Bennett of Bournemouth University is the lead author of this Science paper. He says that most of what we see were made as adolescents. These were America's first teenagers, and they were just as close to each other today. Smartphones were the only thing that was missing back then.
Many other locations have preserved footprints that date back to ancient times. These footprints are often young children or teenagers. Dr Sally Reynolds, another Bournemouth University member, said that older adults tend to stay still and not lose energy.
Young people are more mobile than ever and leave a greater footprint. This was like parents sitting at the school gates and talking, while their children ran around the playground.
It is possible that White Sands teens were helping adults to track and hunt megafauna in the area. These huge animals would include dire wolves, mammoths, and sloths. Bennett adds that the teenagers would have been providing non-skilled labour to these hunting groups.
Bournemouth University researchers have previously conducted studies on other White Sands footprints and provided some amazing details about the lives of those who arrived in the area 20,000 years ago. These photographs of ancient lives include the footprints of a woman who set out across the sands carrying a child in her arms. Sometimes, she would put her foot down and little footprints would appear next to hers. This is a beautiful glimpse into the behaviour of our ancestors, which also shows that humans were extremely secure in the open.
Reynolds adds that White Sands is where humans must have established themselves quickly. We evolved in Africa where we weren't apex predators. We were prey for others. It is amazing to see how dominant hunters we were by the time that we arrived in America.
Other animals in the area clearly understood the dangers Homo sapiens posed. One set of prints clearly shows an enormous sloth running away from a group hunters. These data are likely to prove crucial for future research into the connections between megafauna extinction and ancient humans.
These creatures were extinct after the end the ice age. However, some researchers believe that climate change may have also been responsible. Reynolds says that White Sands gives us the opportunity to examine our relationship to megafauna, and gain a better understanding of how our ancestors treated these creatures.
Robin McKie serves as science and environment editor at the Observer
