Jan Bartek – AncientPages.com – Recent research indicates that ancient Homo sapiens may have gained significant advantages from the use of sunscreen, tailored clothing, and cave habitation during the period of magnetic North Pole shifts over Europe approximately 41,000 years ago.
These technological advancements likely offered protection against harmful solar radiation for Homo sapiens residing in Europe. Conversely, Neanderthals appear to have lacked such innovations and consequently vanished around 40,000 years ago.
This study, published in Science Advances and conducted by researchers from the University of Michigan’s Department of Anthropology and Michigan Engineering, reveals that during this era, the North Pole traversed Europe as part of a natural geomagnetic reversal process that has occurred approximately 180 times throughout Earth’s geological history. Although a complete magnetic reversal did not transpire at that time, a weakened magnetic field resulted in auroras visible across much of the globe. It increased exposure to harmful ultraviolet radiation from space.
Concurrently, evidence suggests that Homo sapiens began to produce tailored garments and utilize ochre—a mineral with sun-protective properties—more frequently on their skin. These adaptive behaviors may have facilitated their expansion throughout Europe and Asia during a period when Neanderthal populations were diminishing.
University of Michigan researcher Agnit Mukhopadhyay reconstructed what the magnetic field around Earth may have looked like during the Laschamps excursion, a time period between 42,200 and 41,500 years ago when the north and south poles wandered from their geographic locations. Image credit: Agnit Mukhopadhyay, University of Michigan
“In the study, we combined all of the regions where the magnetic field would not have been connected, allowing cosmic radiation, or any kind of energetic particles from the sun, to seep all the way in to the ground,” said Agnit Mukhopadhyay, lead author and U-M research affiliate in climate and space sciences and engineering ina press release.
“We found that many of those regions actually match pretty closely with early human activity from 41,000 years ago, specifically an increase in the use of caves and an increase in the use of prehistoric sunscreen.”
Wandering Poles
The generation of Earth’s magnetic field is attributed to the movement of molten metals within its outer core. These dynamic motions induce electric currents, which subsequently produce a magnetic field that envelops the planet in a protective halo. This halo serves as a shield against cosmic radiation, which can deplete Earth’s ozone layer and increase ultraviolet light exposure. Additionally, the interaction between these particles and Earth’s magnetic field results in the phenomenon known as aurora.
Mukhopadhyay initiated the development of models to study this interaction using the Space Weather Modeling Framework—a sophisticated numerical tool crafted and maintained by the University of Michigan’s Center for Space Environment Modeling—to examine solar, heliospheric, and planetary space environments, including that of Earth.
The sun persistently emits hot gases and charged particles toward Earth; due to their exceedingly high temperatures, they function as a plasma system. Mukhopadhyay devised a model predicting how this plasma system interacts with Earth’s magnetic field, ultimately influencing auroral formation.
This magnetic field is oriented with north and south poles—the North and South Poles—where it exhibits maximum strength. Consequently, auroras are typically observed at these polar regions. However, throughout history, these poles have occasionally deviated from their conventional geographic positions in events known as “geomagnetic excursions,” according to Mukhopadhyay. The most recent such event was the Laschamps excursion, which occurred approximately 41,000 years ago.
In collaboration with Sanja Panovska from Germany’s GFZ Helmholtz Centre for Geosciences, Mukhopadhyay constructed a three-dimensional reconstruction of Earth’s geospace system by integrating three distinct models: one global model reconstructing the geomagnetic field during the Laschamps excursion; another modeling Earth’s surrounding space plasma environment; and a third predicting Earth’s auroral appearance at that time. The resultant 3D model elucidated where charged particles could penetrate through Earth’s geomagnetic shield.
The researchers determined that during the Laschamps excursion, Earth’s magnetic field diminished to approximately 10% of its present strength. This significant reduction allowed the magnetic poles to shift closer to the equator, causing an expansion of the magnetic field lines. Consequently, auroras would have been visible across Europe and extending into northern Africa.
Subsequently, the researchers superimposed their three-dimensional model of Earth’s space system onto a global scale. They discovered that the Laschamps excursion period, spanning from approximately 41,000 to 39,000 BP, correlated with transformative periods for human populations residing on Earth at that time.
According to Raven Garvey, an associate professor of anthropology at the University of Michigan, Neanderthals and Homo sapiens cohabited in Europe. Homo sapiens, frequently referred to as anatomically modern humans, are believed to have arrived approximately 56,000 years ago. By around 40,000 years ago, Neanderthals were no longer recognized as a distinct species within Europe.
“What some of the differences are between these species, between Neanderthals and anatomically modern humans, that might account for that disappearance has been a major anthropological question for decades,” Garvey said.
During the Laschamps excursion, a time period between 42,200 and 41,500 years ago, the north and south poles wandered from their geographic locations. At this time, aurora, depicted here by gradients of green and yellow, were able to be seen over most of the globe. Image credit: Agnit Mukhopadhyay, University of Michigan
Associate Professor Garvey explained that clothing may have played a significant role in the development of anatomically modern humans. Archaeological evidence suggests that while Neanderthals did not necessarily possess the technological means to produce form-fitting garments, sites associated with anatomically modern humans reveal tools such as scrapers for hide production, as well as needles and awls indicative of sewing practices.
Tailored clothing offered considerable advantages: it provided enhanced warmth, enabling individuals to venture further from their shelters in search of sustenance. Additionally, tailored garments afforded protection against solar radiation, a factor with numerous adverse effects such as ocular pathologies and folate depletion, which can lead to birth defects and increased infant mortality. Thus, possessing protection against solar radiation would have conferred a substantial advantage.
Moreover, Homo sapiens may have intensified their use of ochre—a naturally occurring pigment composed of iron oxide, clay, and silica—utilized by various hominin species over time for painting objects and cave walls or even body decoration.
“There have been some experimental tests that show it has sunscreen-like properties. It’s a pretty effective sunscreen, and there are also ethnographic populations that have used it primarily for that purpose,” Garvey said. “Its increased production and its association primarily with anatomically modern humans (during the Laschamps) is also suggestive of people’s having used it for this purpose as well.”
Finding Caution In The (Solar) Wind
The researchers are careful to underscore that their findings aren’t definitive. However, they are a new way to look at already existing data.
“I think it’s important to note that these findings are correlational and (ours is a) meta analysis, if you will,” Garvey said. “But I think it is a fresh perspective on these data in light of the Laschamps excursion.”
In addition to examining how previous excursions might have affected humans long ago, Mukhopadhyay said the 3D model offers people a way to predict how excursions might affect us in the future.
“If such an event were to happen today, we would see a complete blackout in several different sectors,” he said. “Our communication satellites would not work. Many of our telecommunication arrays, which are on the ground, would be severely affected by the smallest of space weather events, not to mention the human impacts, which would also play a pretty massive role in our day-to-day lives.”
Mukhopadhyay further emphasized that their research underscores the ability of humans to survive on a planet with an atmosphere markedly different from our current one. This finding holds significant implications for the ongoing search for life on planets beyond Earth.
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“Many people say that a planet cannot sustain life without a strong magnetic field,” he said. “Looking at prehistoric Earth, and especially at events like this, helps us study exoplanetary physics from a very different vantage point. Life did exist back then. But it was a little bit different than it is today.”
Study co-authors also include Michael Liemohn, Daniel Welling and Austin Brenner of Michigan Engineering, Natalia Ganjushkina of both Michigan Engineering and the Finnish Meteorological Institute, Ilya Usoskin of the University of Oulu and Mikhail Balikhin of the University of Sheffield.
The study was published in the journal Science Advances
Written by Jan Bartek – AncientPages.com Staff Writer