Science, July 20, 2001

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Buried in the ocean floor are more than 10 trillion tons of methane—twice the amount of all known coal, oil, and other fossil fuels. Methane (CH₄) is also 25 times more potent, molecule for molecule, as a greenhouse gas than carbon dioxide is. That means that the ocean’s hidden methane reservoirs could play havoc with the world’s climate if they were to escape to the atmosphere. Yet most of the methane that does rise toward the surface of the ocean floor vanishes before it even reaches the water. On page 484 of this issue, a team of researchers provides the clinching evidence for where all that methane goes: It is devoured by vast hordes of mud-dwelling microbes that microbiologists once said couldn’t exist.

Continue reading “‘Inconceivable’ Bugs Eat Methane on the Ocean Floor” →

The New York Times, May 27, 2001

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Science, May 11, 2001

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Wendy Gibson is a paleontologist without fossils. A microbiologist at the University of Bristol, U.K., Gibson studies trypanosomes, single-celled parasites that cause sleeping sickness and related diseases. Although trypanosomes infect millions of people and countless mammals, they are as evanescent as they are common. No fossil of a trypanosome exists, and, as Gibson notes, “we can’t replay history.” Nevertheless, she and her colleagues have been able to reconstruct the past 100 million years of trypanosome evolution, as continents have split them apart and their hosts have evolved into new forms, including humans.

Continue reading “Genetic Trees Reveal Disease Origins” →

Science, May 11, 2001

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On certain afternoons in Uganda, bright orange butterflies with black-and-white wings gather together on small patches of low grass, sometimes in the hundreds. Such congregations are nothing unusual in the animal kingdom; normally, males convene to try to win the attention of females. But the swarms—known as leks—that Acraea encendana form are bizarre: 94% of the butterflies are females, and they jostle for the attention of the few males, who seem reluctant suitors. “You wouldn’t expect males to be surrounded by all these virgin females and not wanting to mate,” says Francis Jiggins of Cambridge University. Even more bizarre is the cause of their sexual skew: They are plagued with a strain of bacteria known as Wolbachia, which kills males but spares females.

Continue reading “Wolbachia: A Tale of Sex and Survival” →

Natural History, March 31, 2001

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When Tim Griffin and Rodger Kram set out to study how penguins walk, they didn’t expect to be impressed. Compared with long-legged ostriches striding across a plain, waddling penguins come up short. Underwater they may be able to race like torpedoes in tuxedos, but on land they are more apt to evoke laughter than to inspire respect.

Previous research on penguins seemed to back up the laughter with hard numbers. Pound for pound, a penguin on land uses twice as much energy as other animals of its size to walk a given distance. Scientists laid the blame for this expense on waddling, the (presumably) energetically costly business of the bird’s throwing its body first to one side and then to the other as it walks.

Continue reading “The Fine Art of Waddling” →