Category: Articles

New Technologies Allow Scientists to Watch Cells in Motion

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The New York Times, June 8, 2009

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It’s easy to imagine the cells in our bodies like bricks in a house, all cemented into place. But we are actually seething with cells that creep, crawl, and squirm. They start wandering soon after conception, and, throughout our lives, our bodies continue to hum with cellular traffic.

Some cells burrow into old bone so that new bone can be laid down in their wake. The tips of new blood vessels snake forward, dragging the cells behind along with them. White blood cells race along on flickering lobes to chase down bacteria before they can make us sick.

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On the Origin of Sexual Reproduction

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Science, June 5, 2009

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For Darwin, sex was a big question mark. “We do not even in the least know the final cause of sexuality; why new beings should be produced by the union of the two sexual elements,” he wrote in 1862. “The whole subject is as yet hidden in darkness.”

Today, biologists understand the molecular nuts and bolts of sex fairly well. Each new human being (or bird or bee) needs a set of chromosomes from each parent. But that’s the how. The why of sex is still fairly mysterious. Bacteria don’t have to search for a mate; they just grow and divide in two. An aspen tree can simply send out shoots that grow into new trees. No muss, no fuss with finding a partner, fertilizing an egg, and joining two genomes.

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Previous Eras of Warming Hold Warnings for Our Age

Posted on by Matt Kristoffersen

Yale Environment 360, May 20, 2009

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The earth’s climate has, of course, fluctuated frequently — and at times wildly — over hundreds of millions of years, long before humans began pouring heat-trapping gases into the atmosphere. So why the concern over the current surge of warming, brought about largely by human activity? Anthony Barnosky, a University of California, Berkeley, scientist who has studied previous eras of climate change, succinctly sums up the problem: Too much warming, too fast.

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Chemicals in Dragon’s Glands Stir Venom Debate

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The New York Times, May 18, 2009

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The Komodo dragon is already a terrifying beast. Measuring up to 10 feet long, it is the world’s largest lizard. It delivers a devastating bite with its long, serrated teeth, attacking prey as big as water buffaloes.

But in a provocative paper to be published this week, an international team of scientists argues that the Komodo dragon is even more impressive. They claim that the lizards use a potent venom to bring down their victims.

Other biologists have greeted the notion of giant venomous lizards with mixed reactions. Some think the scientists have made a compelling case, while others say the evidence is thin.

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Can a Single Neuron Tell Halle Berry From Grandma Esther?

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Discover, May 15, 2009

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Four decades ago, an MIT neuroscientist named Jerry Lettvin had a sudden inspiration about how our brains make sense of the world. What if each of us had a special set of neurons in our head whose only job was to recognize a particular person, place, or thing? It was a strange idea, but given what Lettvin knew about the brain, it was plausible. To describe his idea to his students, he made up a story [pdf].

The story was about Alexander Portnoy, the protagonist of Philip Roth’s novel Portnoy’s Complaint, which had just been published. The novel is a long monologue delivered by Portnoy as he lies on the couch of his psychoanalyst.

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