She Has Her Mother's Laugh by Carl Zimmer

Up in Cambridge, they were toying with metal rods and clamps, searching for plausible arrangements of DNA. Two other scientists, Francis Crick and James Watson, did not want to wait. But Franklin was relentlessly methodical, refusing to indulge in flights of fancy before the hard work of collecting data was done. Looking at the pictures, she suspected that DNA was a spiral-shaped molecule-a helix. Other scientists had tried to take pictures of DNA, but no one had created pictures as good as Franklin had. The beams bounced off the crystals and struck photographic film, creating telltale lines, spots, and curves. She and a graduate student named Raymond Gosling created crystals of DNA, which they bombarded with X-rays. “In 1950, a thirty-year-old scientist named Rosalind Franklin arrived at King’s College London to study the shape of DNA. She Has Her Mother's Laugh: What Heredity Is, Is Not, and May Become The officials agreed to the plan, and when DeLong later gave children from the region IQ tests, their average score jumped 16 points.” Crops would absorb it in their water, and people in the Taklamakan region would eat it in their food. DeLong and his Chinese medical colleagues approached local officials with a different idea: They would put iodine in the irrigation canals. Rumors spread that government-issued iodized salt had contraceptives in it, as a way to wipe out the community. It didn’t help that the people of the region, the Uyghurs, distrusted the government in Beijing. The region has extremely low levels of iodine in the soil, and the people in the region have resisted attempts to introduce iodized salt.

In 1990, Robert DeLong, an expert on iodine at Duke University, traveled to the Taklamakan Desert in western China. But as public health workers continue to bring iodine to more of the world, the same jumps happen. It may be hard to believe that such a straightforward change in people’s diets could have such a tremendous effect on intelligence. And in the parts of the country where natural iodine levels were lowest, Feyrer and his colleagues estimated that scores leaped 15 points. Nationwide, the researchers found, the introduction of iodine raised the average IQ by an estimated 3.5 points.

“Reviewing the records of two million recruits, Feyrer and his colleagues also checked the natural iodine levels in their hometowns.

She Has Her Mother's Laugh by Carl Zimmer