Neanderthal Eustachian tube morphology lowered population-wide fitness and contributed to extinction

Among modern humans, otitis media (benign otitis media with effusion and acute otitis media, AOM) is the second most common pediatric clinical conditions. Acute otitis media is a fatal disease that can result in meningitis and pneumonia if untreated. Osteological signs of this disease may be found in erosion patterns on the middle ear ossicles, ossification of the tympanic membrane, and a lack of mastoid pneumatization. Recent studies report that nearly all known Neanderthal ossicles exhibit erosion patterns consistent with chronic AOM. To account for the anatomical basis of this apparent disease susceptibility, we assessed the morphological configuration of the cartilaginous Eustachian tube (CET) and dilator tubae (DT) musculature among a modern human growth series ranging from newborns to adults (n=442) and a sample of Neanderthals (La Chapelle aux Saints 1, La Ferrassie 1, Forbes Quarry 1, Saccopastore 1, Guattari 1) and mid-Pleistocene pre-Neanderthals (Atapuerca 5 and Steinheim 1). We performed morph...