Discover, May 1, 1996

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Monarchs fly a multigenerational circle around the eastern United States every year. In the fall the last generation heads for Mexico.

When we think of the great animal migrations, we tend to think of great animals–creatures like caribou or wildebeests. But one of the most spectacular movements of life is undertaken by the four-inch-wide monarch butterfly. Every fall tens of millions of monarchs disappear from the United States. Until the mid-1970s, no one knew where they went; it was only then that an amateur lepidopterist found their hiding place in a high mountain range in Mexico.

Continue reading “The Flight of the Butterfly” →

Discover, March 31, 1996)

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When our vertebrate ancestors debuted about 520 million years ago, they didn’t take the world by storm. Inches long and jawless, they grabbed helpless worms with their lips, much as a toothless, armless man might eat a hot dog. Only when fish developed jaws 460 million years ago did Earth see serious predation. “As soon as jaws evolved, there was a revolution,” says Jon Mallatt, a zoologist at Washington State University. “You got all these giant-jawed vertebrates that were at the top of the food chain and eating really big things–just mean, nasty carnivores all of a sudden. And one of these groups gave rise to the land vertebrates. So jaws were a big event. Without them we wouldn’t be here.”

Continue reading “Breathe before you bite” →

Discover, March 1, 1996

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Jaws may be nature’s version of a plowshares-to-swords program: They seem to have originally evolved to help fish breathe better.

When our vertebrate ancestors debuted about 520 million years ago, they didn’t take the world by storm. Inches long and jawless, they grabbed helpless worms with their lips, much as a toothless, armless man might eat a hot dog. Only when fish developed jaws 460 million years ago did Earth see serious predation.

Continue reading “Death From the Pleistocene Sky” →

Discover, February 1, 1996

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Number theory and neuroscience are probably not the first things that come to mind when you contemplate the circus. Yet along with the clowns and the fire-eaters, there’s a place for science under the big top. Performers and their coaches have to know, either instinctively or consciously, what the laws of physics and biology will permit them to do; moreover, a surprisingly large number of scientists are themselves circus fanatics, and a few are even performers. Perhaps it’s because the circus proves that science doesn’t stop at the lab door.

Continue reading “Circus Science” →

Discover, January 18, 1996

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