Scientific American, March 2014

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The Nuvvuagittuq greenstone belt doesn’t look like a battlefield. It lies in peaceful, roadless isolation along the northeastern edge of Hudson Bay in Canada, more than 20 miles from Inukjuak, the nearest human settlement. From the shoreline, the open ground swells into low hills, some covered by lichens, some scraped bare by Ice Age glaciers. The exposed rocks are beautiful in their stretched and folded complexity. Some are gray and black, shot through with light veins. Others are pinkish, sprinkled with garnets. For most of the year the only visitors here are caribou and mosquitoes.

But this tranquil site is indeed a battleground—a scientific one. For almost a decade rival teams of geologists have traveled to Inukjuak, where they have loaded canoes with camping gear and laboratory equipment and trekked along the coast of the bay to the belt itself. Their goal: to prove just how old the rocks are. One team, headed by University of Colorado geologist Stephen J. Mojzsis, is certain that the age is 3.8 billion years. That is pretty ancient, though not record setting.

Continue reading “The Oldest Rocks on Earth”

National Geographic, February 28, 2014

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Van Wedeen strokes his half-gray beard and leans toward his computer screen, scrolling through a cascade of files. We’re sitting in a windowless library, surrounded by speckled boxes of old letters, curling issues of scientific journals, and an old slide projector that no one has gotten around to throwing out.

“It’ll take me a moment to locate your brain,” he says.

On a hard drive Wedeen has stored hundreds of brains—exquisitely detailed 3-D images from monkeys, rats, and humans, including me. Wedeen has offered to take me on a journey through my own head.

Continue reading “Secrets of the Brain”

PHOTO BY RAM GAL, BEN-GURION UNIVERSITY

If you’ve never met the emerald jewel wasp, let me introduce you to my little friend. The wasp (Ampulex compressa) lives the first stage of its life as a parasite, growing inside the body of a living cockroach. 

Ampulex compressa. Photo by K. Seltmann, via Creative Commons. Link: http://www.morphbank.net/?id=102143

That’s absorbingly horrific on its own, but how it gets into the cockroach in the first place is an especially gruesome delight. Its mother has to play neurosurgeon. Continue reading “Crawling Through The Brain Without Getting Lost”

The New York Times, February 27, 2014

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Forcing male flies into monogamy has a startling effect: After a few dozen generations, the flies become worse at learning.

This discovery, published on Wednesday in the Proceedings of the Royal Society, isn’t a biological excuse for men who have strayed from their significant other. Instead, it’s a tantalizing clue about why intelligence evolved.

The new study was carried out by Brian Hollis and Tadeusz J. Kawecki, biologists at the University of Lausanne in Switzerland. They investigated a fly species called Drosophila melanogaster that normally has a very un-monogamous way of life.

Continue reading “Stupider With Monogamy”

A GIANT IMPACT ON THE EARLY EARTH. PAINTING BY DON DAVIS/NASA

About 4.567 billion years ago, a quivering bead of magma 93 million miles from the Sun cooled down until it grew a skin of rock. Eventually, it would be named Earth. We don’t know a lot about what the planet was like back then, because that primordial crust is almost entirely recycled–eroded away, pushed back down into the molten depths of the planet, or smashed to bits by the huge impacts that blasted Earth for its first few hundred million years.

Geologists have wandered the planet to find scraps of the infant Earth. One mineral that is particularly precious to them is known as a zircon. Tiny zircon crystals can withstand billions of years of abuse–getting ripped out of their original rock, incorporated into new rocks, heated up, and squeezed at tremendous pressures–and yet still retain their original chemistry. Zircons have the added attraction of holding onto radioactive isotopes such as uranium. Over billions of years, the uranium decays at a steady rate into lead. By measuring the atoms of uranium and lead in a zircon, scientists can get a tight estimate of the zircon’s age. Continue reading “Searching For the Oldest Pieces of Earth”