Q. Crowded teeth, cavities, gum disease, impacted wisdom teeth — why are we humans afflicted with so many dental problems?
A. “Most other vertebrate creatures do not have the same problems that we do,” says dental anthropologist Peter Ungar in “Scientific American” magazine. “They rarely have crooked teeth or cavities. Our fossil forebears did not have impacted wisdom teeth, and few appear to have had gum disease.” The teeth of modern-day humans are the hardest parts of our body yet are incredibly fragile, a contradiction limited to industrial-age and contemporary populations and indicative of “a mismatch between today’s diets and those for which our teeth and jaws evolved.”
Consider dental caries (cavities), the most common and pervasive chronic disease in the world, afflicting more than nine in 10 Americans and billions of people across the globe. The biggest jump in the caries rate came with the Industrial Revolution and our modern diets, “unlike any in the history of life on our planet.” Highly processed foods are softer and cleaner, requiring less chewing to cut the organic film and with fewer dietary abrasives to smooth areas where plaque bacteria build up. As cavities grow, they can overwhelm the natural defenses of the teeth.
Basically, Ungar explains, “from an evolutionary perspective, a couple of centuries is… not nearly enough time for our teeth to adapt to the changes in our oral environment wrought by the introduction of table sugar and processed foods.”
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Q. If you’re a frequent internet user, you undoubtedly know the meaning of “meme,” something that spreads all over the net. But do you know its origin? And what about the origin of “vaccine”?
A. Evolutionary biologist Richard Dawkins created the word “meme” when he was hunting for an idea-focused counterpart to the concept of a gene, says David Silverberg in “New Scientist” magazine, drawing on the new podcast “Science Diction,” hosted by Johanna Mayer. Looking for a word to indicate what happens when cultural phenomena replicate themselves over and over, Dawkins borrowed from the Greek “mimema” (imitated), blended it with “gene” and created “meme.”
“Vaccine,” dating back to the late 18th century, was coined by British physician Edward Jenner when testing whether using cowpox could prevent the related but deadly disease smallpox. He gave cowpox to an 8-year-old boy and then exposed him to a sample of smallpox, itself a violation of “about 1000 ethical rules, but it went down in history as the first official scientifically documented vaccination,” says Mayer. Jenner drew on the Latin words “variola” (pustules) and “vacca” (something from a cow); hence, “variola vaccine” refers to cow pustules or cowpox. Despite being exposed to smallpox dozens of times, the boy never contracted the disease.
A FOND FAREWELL
In this season of uncertainly, it might be helpful to remind ourselves of this paramount fact: As of May 2020, the world’s population was 7.8 billion. If that number doesn’t sound very big, consider that it would take someone an estimated 250 years to count to 7.8 billion out loud.
Looking at the balance of things, every second about 4 people are born and 2 people die. As these numbers add up, we’ll probably reach 9 billion by 2045.
Today’s 7.8 billion people reside in 194 countries and speak some 7,000 languages. A relatively few more are male than female, with a median age of 30 years. Most are right-handed.
In the sweep of time, a total 100 billion humans have lived on Earth, and of these, only 7.8% are living today. Lucky us! As we close the book on our “Strange But True” column, we bid you, our loyal readers, a fond farewell. We thank you and wish you well in the coming years.