Were Neanderthals Getting Surfer’s Ear From Diving for Seafood?

The bony growths appear after repeated exposure to cold water and were found on half of the Neanderthal skulls examined

Neanderthal Ear Growths
Surfer's Ear growths in Neanderthal ear canals. PLOS One

New evidence that Neanderthals got surfer’s ear suggests our extinct relatives spent a lot of time in the water. They probably weren’t catching sick waves, but instead they were perhaps hunting fish, mollusks or other marine resources, a new study in the journal PLOS One shows.

Surfer’s ear is different from the more common swimmer’s ear, which is a bacterial infection in the outer ear canal. In exostosis, the ear canal begins to grow bony protrusions in response to repeated exposure to cold, moist conditions. It’s the body’s way of protecting the eardrum, but the growths can lead to hearing loss, wax impaction and increased infection.

Issam Ahmed at AFP reports that as far back as 1911, paleontologists noticed exostosis growths on a Neanderthal skull, but until this most recent study, no one had looked deeper into the matter. That’s why a team led by paleoanthropologist Erik Trinkaus at Washington University in St. Louis examined 77 remains of early Homo sapiens and Neanderthals uncovered in Europe and West Asia.

They found that surfer’s ear existed in about a quarter of the human skulls, similar to the rate the disease occurs in humans today. But nearly half of the Neanderthals examined had the mild to severe cases of the condition, suggesting that the ocean played a big role in their lives. And if they were fishing, it means they may have been more advanced than some researchers believe.

“It reinforces a number of arguments and sources of data to argue for a level of adaptability and flexibility and capability among the Neanderthals, which has been denied them by some people in the field,” Trinkaus tells AFP’s Ahmed. “You have to be able to have a certain minimal level of technology, you need to be able to know when the fish are going to be coming up the rivers or going along the coast—it's a fairly elaborate process.”

This isn’t the only paper to suggest the ear problem is a sign Neanderthals liked seafood. A 2017 paper, noting the prevalence of the condition in Neanderthals and early humans, suggests that it was an evolutionary adaptation to early hominins diving into cold lakes, rivers and seas to collect food.

Trinkaus anticipates that the finding will be controversial and there are some reasons to doubt that Neanderthals were particularly fond of fish. Genelle Weule at the Australia Broadcasting Network reports that researchers have not discovered fish bones at Neanderthal camps or tools that would have been used for fishing or aquatic foraging. Many of the Neanderthal remains discovered so far come from inland areas as well as the coasts. And the isotopic analysis done so far on Neanderthal bones have found that their diets were primarily terrestrial and not from the ocean. It’s also possible that genetics play a part, and that Neanderthals were more disposed to getting the bony growths than humans.

Neanderthals were spread across a large range and they drew resources from many habitats, which could explain some discrepancies. Most inland camps were in relatively close proximity to water, he says. He also points out that many coastal Neanderthal camps are likely underwater today and not accessible to researchers.

Whatever the case, recent studies are beginning to overturn previous notions of the Neanderthal diet, says Steve Wroe, director of the Function, Evolution and Anatomy Research Lab at the University of New England.

“For a very long time it was considered Neanderthals basically went around with big pointy sticks getting in close and dirty with big hairy animals and killing them," Wroe tells Australia Broadcasting Network. “There’s no doubt they were effective hunters, but it’s become increasingly clear they certainly ate vegetable matter, they certainly fitted a bit more of a real hunter gather sort of group than just a purely carnivorous low-tech, high incidence-of-injury kind of people.”

Trinkhaus equates this recent study with another controversial paper in 2018 that claimed the oldest cave art in Spain was likely made by Neanderthals, not humans. He says this study is just part of an emerging picture of the species showing that their behavior and cognitive abilities were close to our own.

“We're going beyond whether we share their genes, or whether they gave rise to us, to ‘let’s try to understand them as people,’” he tells Ahmed.

As Lorraine Boissneault wrote earlier this year for Smithsonian.com, researchers are still learning exactly what behaviors are associated with surfer’s ear. For instance, several cases of the condition were found in skeletons of people living in Panama between 500 to 2,500 years ago. Typically, warm, tropical waters don’t lead to the bony growths, but many of the people with the condition lived in coastal communities where diving into deeper, chillier waters for oysters and conch was common. Perhaps, they were even searching for pearls.

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