Wild Things: Life as We Know It

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Sharks rarely swim deeper than 10,000 feet • Worldwide, erosion spoils an Indiana-size 37,000 square miles of cropland yearly

Cruise To The New World?

Long ago, as many of us learned in school, some Asian peoples likely walked across the Bering Strait land bridge to North America. But some archaeologists believe that the first emigrants came by sea more than 20,000 years ago, when the land route was blocked by ice. Now Jon Erlandson, an archaeologist from the University of Oregon, suggests those pioneers set off in boats into a Pacific kelp forest and then followed a “kelp highway” stretching from Japan up the coast of Asia, east to Alaska and down to South America. Along the way, people would have caught fish, sea cows, otters and seabirds, and their passage would have been eased by the surf-subduing seaweeds.

Not Dead Yet

Visiting a meat market in Laos last year, scientists came across a strange bushy-tailed rodent that they thought was a new species. But now paleontologists at the Carnegie Museum of Natural History in Pittsburgh say the truth is even stranger: the nocturnal animal known to Laotians as the kha-nyou (right) is a type of rodent that scientists thought had been extinct for 11 million years.

The Smart Set

Orangutans living in isolated groups share so many distinctive learned behaviors—from the sounds they make to how they eat—that primatologists say such groups have their own cultures. Now Carel van Schaik of the University of Zurich, who studies orangutans in Sumatra and Borneo, finds that the more time members of a group spend together, the richer each orangutan’s repertoire of behaviors, apparently because they have lots of opportunities to learn from one another. His conclusion? “Culture makes you smart.”Orangutans living in isolated groups share so many distinctive learned behaviors—from the sounds they make to how they eat—that primatologists
say such groups have their own cultures. Now Carel van Schaik of the University of Zurich, who studies orangutans in Sumatra and Borneo, finds that the more time members of a group spend together, the richer each orangutan’s repertoire of behaviors, apparently because they have lots of opportunities to learn from one another. His conclusion? “Culture makes you smart.”

Time To Eat

Hummingbirds dart from flower to flower, draining each blossom of its nectar. But new research suggests they’re not just zooming around recklessly—they’re on a tight schedule. Flowers refill with nectar every few hours, so hummingbirds would be smart to remember where and when they’ve already eaten. Researchers working at a field station in Alberta, Canada, filled eight flower-shaped feeders with a shot of sugar water every 10 or 20 minutes. Rufous hummingbirds bellied up to each feeder at about the time it was refilled, showing they could keep track of eight different food sources—a useful skill for fueling such buzzing exuberance.

Observed

Name: Daphnia pulex, or water flea.
Once Noted For: Reproducing both sexually and asexually.
Now Noted For: Providing evidence that sex is better.
This Was In Doubt? Yes. Sexual reproduction costs lots of energy, and an individual that engages in it—unlike one that clones itself—passes along only half of its genes. Scientists have long wondered why organisms bother. A new study by Indiana University biologists shows that asexual D. pulex populations accumulate harmful genetic mutations four times faster than their sexual counterparts—strongly suggesting that combining one’s DNA with a partner’s, rather than simply replicating it, is a more efficient way to clean the gene pool.