Why did our species survive when Neanderthals and all other human species went extinct? The theories are many, and now there's a new contribution to the pile: maybe our early childcare was more nurturing. The new theory presented Thursday in Scientific Reports is based on the state of dental enamel in Neanderthals living 400,000 and 40,000 years ago, and modern humans from 50,000 to 12,000 years ago. The study by Laura Sophia Limmer and Sireen El Zaatari of Germany's University of Tübingen and colleagues analyzed teeth from 74 Neanderthals and 102 modern humans living in Upper Paleolithic Europe.
Our adult teeth start developing during our infancy. The new thesis is predicated on the quality of our adult dental enamel being a factor not only of heredity but environment too: the care we are given in early childhood. To oversimplify a tad, the better we are fed, the better our enamel is and the more resilient our teeth are to decay and breakage.
There are caveats. Defective enamel formation , aka hypoplasia, appearing as horizontal grooves of thinner enamel on our permanent teeth, may be caused by bad genes and/or sickness such as respiratory diseases and even chicken pox, especially when combined with toxic environmental factors such as secondary hearth or cigarette smoke. But crucially to the new paper, enamel flaws may also be caused by calcium deficiency and malnutrition in childhood.
The temporal overlap between the sampled Neanderthals (400,000 to 40,000 years ago) vers.