Aug. 15 (UPI) -- The malady of the inner ear known as "swimmer's ear" was surprisingly common among Neanderthals, according to a new study.
Swimmer's ear is irritation of the ear canal. The condition often triggers the protrusion of dense bony growths, called external auditory exostoses, into the ear canal. The malady is typically caused by prolonged exposures to cold, wet environs.
Researchers have previously found evidence of swimmer's ear among the remains of Neanderthals, but the latest study is the first to take a comprehensive look at its prevalence among the archaic human species.
Scientists analyzed the remains of 77 ancient humans, both Neanderthals and early modern humans. All of the remains were dated to the Middle to Late Pleistocene Epoch, from 300,000 to 10,000 years ago, and were recovered in western Eurasia.
External auditory exostoses were found in the ear canals of half of the Neanderthal remains, twice the rate of swimmer's ear found among early humans.
The research, published this week in the journal PLOS One, showed Neanderthals living in colder climates weren't more likely to suffer from swimmer's ear. Researchers also failed to find a link between the prevalence of external auditory exostoses and proximity to water sources.
Researchers suspect a combination of genetic and environmental factors account for the elevated frequency of external auditory exostoses found among Neanderthals.
"An exceptionally high frequency of external auditory exostoses among the Neanderthals, and a more modest level among high latitude earlier Upper Paleolithic modern humans, indicate a higher frequency of aquatic resource exploitation among both groups of humans than is suggested by the archeological record," Erik Trinkaus of Washington University said in a news release. "In particular, it reinforces the foraging abilities and resource diversity of the Neanderthals."