BY THE OPTIMIST DAILY EDITORIAL TEAM
With summer around the corner and UV levels on the rise, sunscreen is about to be a seasonal staple for most of us. But if you think the idea of sun protection is a modern invention, think again. New research from the University of Michigan suggests our ancestors may have relied on a prehistoric version of sunscreen to survive a cosmic crisis 41,000 years ago.
During a period known as the Laschamps excursion, the Earth’s magnetic field underwent a temporary but extreme weakening. The magnetic poles wandered far from their usual locations, and the field itself dropped to just 10 percent of its normal strength. This left the planet far more exposed to cosmic and ultraviolet radiation—with serious risks to eyesight, reproduction, and survival.
So how did early Homo sapiens endure this event, while their Neanderthal cousins mysteriously disappeared? Archaeological and climate evidence offers a compelling clue: ingenuity.
When the sky turned dangerous
The Earth’s magnetic field normally acts as a protective shield, deflecting cosmic radiation and solar particles. But geomagnetic excursions—temporary shifts in the magnetic poles—can throw this shield into chaos. The Laschamps event, confirmed by tree ring data and new 3D geospace models, brought intensified radiation to the surface of the planet, particularly across Europe, where the North Pole had drifted.
To cope, Homo sapiens appear to have gotten creative. Evidence from archaeological sites shows a spike in cave use during this period, providing natural shelter from radiation. Bone tools such as awls and needles also suggest an uptick in tailored clothing—another barrier between sensitive skin and solar exposure.
But perhaps the most intriguing adaptation? The increased use of ochre, a naturally occurring clay earth pigment rich in iron oxide. Known primarily for its use in cave art, ochre may have served a more practical, sun-blocking purpose.
“It’s a pretty effective sunscreen,” says Raven Garvey, an associate professor of anthropology at the University of Michigan. “There have been some experimental tests that show it has sunscreen-like properties.”
Applied to the skin, red and yellow ochre can deflect UV rays much like modern mineral sunscreens. And it appears this innovation was more common among anatomically modern humans than among Neanderthals.
Survival through adaptation
The researchers caution that the findings are correlational, not conclusive. But the evidence paints a compelling picture: as radiation levels surged, Homo sapiens sought shelter, tailored their clothing, and smeared on a little natural sunblock. These survival strategies may have given them a critical edge.
As we head into another sun-soaked summer, it turns out that protecting our skin isn’t just about comfort or vanity. It might be one of the oldest tricks in the Homo sapiens playbook.
Source study: Science Advances— Wandering of the auroral oval 41,000 years ago
