Preserved Ice Age Footprints Challenge Scientists’ Understanding of How and When People First Reached North America

If the preserved footprints discovered in New Mexico's Lake Otero Basin are authentically dated, it will completely change how and when humans first came to North America. A recent study calls into question the age assertion.

Footprints claimed as evidence of ice age humans in North America

(Photo : Torsten Dederichs/Unsplash)

In New Mexico, the broad expanse of a dried-up lakebed contains the well-preserved footprints of ancient life, as per ScienceDaily.

Along with the signs left by giant sloths and mammoths, our ancestors the humans also left their mark.

These footprints, which date from between 23 and 21 thousand years ago, are said to be "definitive evidence of human occupation of North America" during the last ice age, according to research that was published in September 2021. A recent study contests the evidence supporting such a young age.

In Quaternary Research, researchers from DRI, Kansas State University, the University of Nevada, Reno, and Oregon State University warn that the dating evidence is insufficient to support claims that would so fundamentally change our understanding of when and how humans first arrived in North America.

The new study demonstrates that the footprints may have been left thousands of years later than initially thought by using the same dating technique and materials

According to Charles Oviatt, emeritus professor of geology at Kansas State University and one of the study's authors, "I read the original Science article on the human footprints at White Sands and was initially struck not only by how tremendous the footprints were on their own, but how important accurate dating would be."

Paleogeneticists believe that the American Southwest was first inhabited no earlier than 20 thousand years ago based on the analysis of ancient DNA from human fossils and rates of genetic change (a sort of molecular clock using DNA).

The validity and use of these genetic models are called into question if the footprints are older.

The authors write that the ages from a single study at a single site in a New Mexico lake basin may be accurate, and that age estimates from numerous other fields are inaccurate, but stronger proof is required to support the claims.

By analyzing Ruppia plant material from the same region that had an established age, the authors were able to demonstrate this effect.

Living Ruppia plants were gathered by botanists in 1947 from a nearby spring-fed pond, and they were stored at the University of New Mexico herbarium.

The plants that were alive in 1947 gave the same radiocarbon date, which indicated that they were approximately 7400 years old.

This offset was caused by the plant's use of ancient groundwater.

The Ruppia seeds' true age, according to the authors, would be between 15 and 13 thousand years old, which is consistent with the ages of several other well-known early North American archaeological sites. If the ages of the Ruppia seeds dated from the human footprints were also offset by roughly 7400 years, the authors note.

Read more: Prevailing Ice Age Theory Debunked by Scientists in a New Study

How Humans Survived the Ice Age

In addition to having the natural ability to endure a variety of climates, Homo sapiens can also withstand periods of extreme climate change, as per Discover Magazine.

Humans were able to endure the extreme weather changes that their hominin relatives could not endure during the Ice Age, which began approximately 115,000 years ago. How did these people manage it?

Presently, anthropologists and archaeologists are without a conclusive solution.

However, the hazy theories and speculative explanations frequently highlight our species' exceptional social skills and propensity for modifying our environment to our advantage.

We were not the only hominins present at the start of the Ice Age. The Indonesian islands were home to the last survivors of the long-lived Homo erectus and the short-statured Homo floresiensis.

Asia was populated by Denisovans. And the Neanderthals were able to endure the harsh winters in Europe.

Although these species, which are our closest evolutionary relatives, had previously flourished, they all disappeared from the archeological record during the Ice Age.

Hominins virtually all vanished during the Ice Age. Only one species persisted. But H. sapiens first appeared on the African continent About 200,000 years before the Ice Age.

This was in many ways a fortunate location. According to Potts, this terrain remained isolated from the full force of glacial activity that other hominins elsewhere experienced when the Ice Age arrived about 200 millennia into our evolution.

Related article: Volcanic Event Triggered Ice Age During the Jurassic Period, Say Researchers