Among scientists who study how our DNA affects our weight, a gene called FTO stands out. “It’s the poster child for the genetics of obesity,” said Struan F. Grant, an associate professor of pediatrics at the University of Pennsylvania School of Medicine.

In 2007, researchers discovered that people with a common variant of FTO tend to be heavier than those without it. Since then, studies have repeatedly confirmed the link. On average, one copy of the risky variant adds up to 3.5 extra pounds of weight. Two copies of the gene bring 7 extra pounds — and increase a person’s risk of becoming obese by 50 percent.

Continue reading “Gene Linked to Obesity Hasn’t Always Been a Problem, Study Finds” →

In 1924, the State of Virginia attempted to define what it means to be white.

The state’s Racial Integrity Act, which barred marriages between whites and people of other races, defined whites as people “whose blood is entirely white, having no known, demonstrable or ascertainable admixture of the blood of another race.”

There was just one problem. As originally written, the law would have classified many of Virginia’s most prominent families as not white, because they claimed to be descended from Pocahontas.

Continue reading “White? Black? A Murky Distinction Grows Still Murkier” →

Each year, scientists publish roughly 17,000 detailed descriptions of newly discovered animals. Recently, in the journal Breviora, researchers described yet another, a new species of lizard called Aspidoscelis neavesi.

At first glance, this seems to be a run-of-the mill lizard: a small, slender creature with spots along its back and a bluish tail. In fact, Aspidoscelis neavesi is quite exceptional. The lizard was produced in the laboratory by mating two other species, and its creation defies conventional ideas about how new species evolve.

The evolution of a new animal species is usually a drawn-out affair.

Continue reading “The Strange Tale of a New Species of Lizard” →

Every disease has a history. Some of that history is written in books, and some is written in our DNA.

The earliest records of meningitis — an infection of the membranes that line the brain — reach back to 1685. The British physician Thomas Willis described fevered patients, some of whom suffered from “continual raving” and others who suffered from “horrible stiff extensions in the whole body.”

But meningitis was a threat long before Willis put quill to paper.

Continue reading “An Evolutionary Battle Against Bacteria” →