“A genetic contribution to a trait, if there is one, does not necessarily sentence you to a life with that trait,” said Feldman. This goes to show that in many cases, lifestyle choices can have just as powerful if not more of an influence on human traits than underlying genetics. For instance, since World War II, a switchover from heavy rice consumption to more dairy and protein in childhood has been linked to Japanese men gaining around 5 inches in average adult height. Instead, profound physiological changes can occur in human populations over short intervals, Feldman pointed out, purely as a result of environmental factors, such as dietary choices and cultural norms. and Mildred Finley Wohlford Professor and professor of biology. “The evidence of a genetic contribution to the jaws epidemic is not strong,” said Feldman, who is a population geneticist and the Burnet C. Nor is there any evidence of selection pressures that would have favored smaller jawed-people producing more offspring – and thus perpetuating the trait – than regular-jawed people. “There’s not been enough time for evolution over the span of only several generations to have made our jaws shrink,” said Ehrlich. According to Ehrlich’s new book, mouth breathing, among other modern habits, has led to an epidemic of small jaws and many troubling health consequences.Īssuming that genetics are chiefly responsible for the sudden modern rise of these dental maladies does not make sense, said Ehrlich. Paul Ehrlich wants you to shut your mouth – for your health.
Science & Technology Paul Ehrlich on the problems of the modern jaw These bygone humans showed little teeth crowding, impaction of their wisdom teeth (a leading reason for their surgical removal nowadays) or malocclusion – the abnormal positioning of the upper and lower teeth when the mouth is closed. The differences are stark even compared to humans who lived as recently as a century-and-a-half ago during pre-industrial times. Rooted in lifestyle, not geneticsĪnthropologists have long noted the significant differences between the jaws and teeth in modern skulls compared to pre-agricultural, hunter-gatherer humans from thousands of years ago. Seng-Mun “Simon” Wong, a general dentist in private practice in Australia, was also a co-author. Two other Stanford researchers, Robert Sapolsky and Marcus Feldman, have contributed their expertise to the new study. The new study builds upon a book Ehrlich co-wrote with orthodontist and lead study author Sandra Kahn entitled Jaws: The Story of a Hidden Epidemic, published by Stanford University Press in 2018. “The jaws epidemic is very serious, but the good news is, we can actually do something about it,” said Paul Ehrlich, the Bing Professor of Population Studies, Emeritus, at Stanford and one of the study’s authors.
Parents and caregivers can take steps to promote proper mouth, jawbone and facial musculature development in children, the study advises, to help stave off future health burdens and chronic conditions.
The story of the human body: evolution, health, and disease reviews how to#
The study – published in the journal BioScience – marshals the growing evidence from studies conducted around the world surrounding the jaws epidemic, as well as how to address it proactively. That means the epidemic is largely the result of human practices and akin to obesity, type 2 diabetes, heart disease and some cancers. Moreover, they maintain that this “jaws epidemic” is not primarily genetic in origin, as previously thought, but rather a lifestyle disease. The broader scientific community has largely deemed the underlying abnormality behind these problems as hereditary and untreatable, and opted to deal with symptoms through medical devices and after-the-fact interventions.īut in a new study, Stanford researchers and colleagues argue that all these issues and more are actually relatively new problems afflicting modern humans and can be traced to a shrinking of our jaws.
A new study says that parents and caregivers can take steps to promote proper mouth, jawbone and facial musculature development in children to help stave off future health burdens and chronic conditions.