Tuesday, September 28, 2021

Ghost Tracks -- Evidence of Humans in North America Over 20,000 Years Ago

These human footprints from what’s now New Mexico may be between 23,000 and 21,000 years old. If so, that would make them some of the best evidence yet that humans were in North America during the height of the last ice age. David Bustos/National Park Service, Bournemouth Univ.

On the right day, given the proper conditions, human footprints can appear out of nowhere on the flats of White Sands National Park in New Mexico. Park scientists call them 'ghost tracks,' and they look like prints from a beachgoer striding across damp sand.

But new research published today in Science reports that at least some of these prints could be tens of thousands of years old, making them potentially the best evidence yet that people reached the Americas far earlier than once believed. Radiocarbon dating of seeds surrounding the prints suggests that they were made during the Last Glacial Maximum, when massive ice sheets are thought to have blocked any passage from the Bering Land Bridge into southern North America.”

(Rachael Moeller Gorman. “Ancient Human Footprints in New Mexico Dated to Ice Age.” The Scientist. September 23, 2021.)

If this claim is validated, we are looking at pushing human occupation back much earlier than almost anybody had anticipated.

I would like to see the researchers use other validation techniques to check the dates before breaking out the champagne. This is the kind of stuff that makes you rewrite textbooks. For the good of the field, we need really high standards But if further verification confirms the age of the tracks, the discovery will show us that people have this amazing ability to survive and thrive during a time when global conditions were extreme.”

Loren Davis, anthropologist at Oregon State University in Corvallis

The new study does leave room for doubt. Its own authors raise the point that radiocarbon dating of aquatic material can sometimes be subject to something called hard-water or “reservoir” effects, which could potentially make the age results too old. But the team radiocarbon dated other local materials and compared it to the seeds, and also examined the placement of the seeds in the layers themselves, to try to address this possibility.

However, the presence of a mammoth track in one of the topmost, or youngest, layers indicates that the upper age of the site can’t be more recent than the late Pleistocene, when the animals went extinct. The researchers write in their paper that, “In our view, an improbable series of events would be required to introduce a large hard-water effect by ~23,000 years ago when such effects were minimal for the previous ~20,000 years.”

(Rachael Moeller Gorman. “Ancient Human Footprints in New Mexico Dated to Ice Age.” The Scientist. September 23, 2021.)


Despite a plethora of archaeological research over the past century, the timing of human migration into the Americas is still far from resolved. These finds indicate the presence of humans in North America for approximately two millennia during the Last Glacial Maximum south of the migratory barrier created by the ice sheets to the north. This timing coincided with a Northern Hemispheric abrupt warming event, Dansgaard-Oeschger event 2, which drew down lake levels and allowed humans and megafauna to walk on newly exposed surfaces, creating tracks that became preserved in the geologic record.

(Matthew R. Bennett, David Bustos, Jeffrey S. Pigati et al. “Evidence of humans in North America during the Last Glacial Maximum.” Science. September 24, 2021. Vol 373. Issue 6562.)

Footprints preserved in the boundless expanses of New Mexico‘s White Sands National Park have drawn the attention of scientists since the early 1930s, when a government trapper spotted a print measuring a stunning 22 inches long and eight inches wide. He was convinced he‘d found evidence for the mythical Bigfoot. (Actually, it was a giant sloth.)

(Debra Adams Simmons. “Were People In the Americas Much Earlier Than Thought? National Geographic. September 27, 2021.)

For years, people have noticed that in particularly wet periods of the year at White Sands National Park in New Mexico, they could see footprints appearing as if out of nowhere on the ground. They would disappear again when the soil dried out, earning them the nickname “ghost tracks.”


By studying the shape, size, and distribution of the footprints, the researchers attempted to piece together what happened during the ancient walk across the muddy ground. The primary track maker could have been either a woman 12 years or older, or possibly a young man, based on a comparison of the footprint lengths to modern humans. In at least three points along the way, tiny footprints join the main trackway, evidence of a child less than three years old.

The spacing of the tracks suggests the person was traveling around 3.8 miles an hour. While not a jog, this would have been a hasty pace considering the muddy conditions and heavy load.

(Matthew R.Bennett, DavidBusto et al.”Walking in mud: Remarkable Pleistocene human trackways from White Sands National Park (New Mexico)” Quaternary Science Reviews. Volume 249, 1 December 2020.)

Many archaeologists have placed the start of human life in the Americas toward the end of the last Ice Age, around 13,000 years ago, reports Carl Zimmer for the New York Times. That’s when some of the oldest known tools, made by the Clovis culture in what is now New Mexico, appear. Melting of ice sheets as the world warmed could have allowed hunter-gatherers to cross a land bridge from Siberia to Alaska.

Since the 1970s, other archaeological work has suggested that humans arrived on the continent earlier, perhaps between 16,000 and 17,000 years ago, traveling down Pacific Coast routes that became passable while the continent’s interior was still icy, writes Maya Wei-Haas for National Geographic.

(Livia Gershon. “Prehistoric Footprints Push Back Timeline of Humans’ Arrival in North America.” Smithsonian Magazine. September 24, 2021.)

Some researchers have also published evidence of a much earlier human presence in North America, including stone tools dated to as long as 30,000 years ago. But others have questioned whether the discoveries were really tools shaped by humans, and whether estimates of their age are correct.

The new White Sands research is different because the prints were obviously made by people, study co-author Vance Holliday, an archaeologist and geologist at the University of Arizona, tells National Geographic.

Even if the study’s findings hold up, the question of what became of North America’s Ice Age inhabitants remains. Andrea Manica, a geneticist at the University of Cambridge who was not involved in the study, tells BBC News’ Paul Rincon that clear evidence of ancestors of modern Native Americans splitting from Asian populations 15,000 to 16,000 years ago exists.

This would suggest that the initial colonists of the Americas were replaced when the ice corridor formed and another wave of colonists came in,” he says. “We have no idea how that happened.”

(Livia Gershon. “Prehistoric Footprints Push Back Timeline of Humans’ Arrival in North America.” Smithsonian Magazine. September 24, 2021.) 

 


Ghost Dance

Patti Smith

What is it children that falls from the sky?
Tayi, taya, tayi, aye aye.
Mannah from Heaven from the most high,
Food from the father, tayi, taye aye.

We shall live again, we shall live again,
We shall live again, shake out the ghost dance.

Peace to your brother, give and take peace,
Tayi, taya, it leaves two feet
One foot extended, snake to the ground,
Wave up the Earth, one turn around.

We shall live again, we shall live again,
We shall live again, shake out the ghost dance.




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