Gert Stulp stands 6 feet, 7 inches tall. His height makes him especially self-conscious at scientific conferences when he rises to describe his research as a demographer at the London School of Tropical Medicine. “It’s always quite embarrassing,” he said.

Dr. Stulp, who is Dutch, studies why his fellow citizens are so tall.

Today, the Dutch are on average the tallest people on the planet. Just 150 years ago, they were relatively short. In 1860, the average Dutch soldier in the Netherlands was just 5 feet 5 inches. American men were 2.7 inches taller.

Continue reading “Natural Selection May Help Account for Dutch Height Advantage” →

Some muscles get all the glory. Bodybuilders show off their swollen triceps; sprinters flash their sharp-edged calves. But deep inside all of us, a sheet of muscle does heroic work in obscurity.

In order to breathe in, we must flatten the dome-shaped diaphragm; to breath out, we let it relax again. The diaphragm delivers oxygen to us a dozen times or more each minute, a half-billion times during an 80-year life.

“We are completely dependent on the diaphragm,” said Gabrielle Kardon, a biologist at the University of Utah. “But we take it for granted every moment we’re breathing.”

Continue reading “Behind Each Breath, an Underappreciated Muscle” →

Scientists in Iceland have produced an unprecedented snapshot of a nation’s genetic makeup, discovering a host of previously unknown gene mutations that may play roles in ailments as diverse as Alzheimer’s disease, heart disease and gallstones.

“This is amazing work, there’s no question about it,” said Daniel G. MacArthur, a geneticist at Massachusetts General Hospital who was not involved in the research. “They’ve now managed to get more genetic data on a much larger chunk of the population than in any other country in the world.”

Continue reading “In Iceland’s DNA, New Clues to Disease-Causing Genes” →

In 1962, the ecologist Robert Whitaker set out to categorize the different realms of life on Earth. Some were deserts, others tundra, still others tropical forests. He coined a word for these inhabited environments, one that scientists have used ever since: biomes.

The planet’s biomes emerged over hundreds of millions of years. Coastal wetlands sprang up along the edges of continents about 400 million years ago. About 20 million years ago, grasslands became widespread. But the biome that we’re most familiar with — one that has a huge impact on our everyday life — is the youngest of all: the indoor biome.

Continue reading “The Next Frontier: The Great Indoors” →