Random Samples

Science  07 Sep 2007:
Vol. 317, Issue 5843, pp. 1301


    Women have an evolved knack for remembering where to find edible plant matter, a new study argues.

    Rafts of studies have shown that men trump women at many spatial skills, a spillover from our past, say evolutionary psychologists, when men were the hunters and women the gatherers. Studies have also shown that women beat out men in recalling objects' locations. But no one had tested this skill with foods.

    So a team led by Steven Gaulin of the University of California (UC), Santa Barbara, tested modern city dwellers on the closest thing to foraging: browsing in a farmers' market. After looking around the stalls, the 86 subjects were asked to remember where they'd seen particular foods. The test involved dead reckoning, a male-dominated skill, rather than navigating by landmarks, a female forte. Yet women were 27% more accurate than men in recalling food locations, the scientists reported online 21 August in the Proceedings of the Royal Society B.

    “The results fit well with the foraging adaptation theory that explains why women should perform better than men in such a spatial cognition task,” says evolutionary psychologist Andreas Wilke of UC Los Angeles. But he notes that both sexes “were significantly more accurate in locating high-calorie food items,” such as avocados and olive oil.

  2. NETWATCH: Lights, Camera, Clarify

    A difficult paper might be easier to grasp if you could get an explanation directly from the authors. That's the premise behind SciVee, a new video-sharing site from the Public Library of Science, the National Science Foundation, and the San Diego Supercomputer Center.

    Part YouTube, part seminar series, SciVee allows researchers to post short videos, or pubcasts, in which they explicate their latest papers. The offerings explore a technique for identifying bendable sections of proteins and follow an evolutionary analysis of the protein kinase-like superfamily, which is involved in everything from cell division to fat breakdown. For newbies, the site offers advice on video production and posting. So far, SciVee's focus is open-access papers in biology, but it will expand to include other subjects and types of publications.



    White peppered moth almost impossible to spot (arrow).


    A Cambridge University professor has completed a 6-year experiment with peppered moths that he says should conclusively rebut creationist claims.

    The story of Britain's peppered moth has long been a textbook illustration for evolution by natural selection. The pale moths evolved a black color for camouflage against predators as industrial pollution darkened the trees they rested on. With pollution cleanup, most of the moths went back to being pale. But creationists have used the tale to attack evolution because field experiments done in the 1950s by Oxford zoologist Bernard Kettlewell—used to illustrate the textbooks—were flawed, in part because he released the night-flying moths during the daytime.

    So in 2000, geneticist Michael Majerus started his own experiment (Science, 25 June 2004, p. 1894). He released black or white moths into cylindrical cages on branches at dusk. Before dawn, he removed the cages and counted how many moths subsequently disappeared from their resting places. He showed that selection now favors pale moths, with 21% eaten by birds, compared with 29% of the black ones, he reported last week at a meeting of the European Society for Evolutionary Biology in Uppsala, Sweden.

    Will that take any wind out of creationists' sails? “It's probably not going to quiet them down,” says peppered moth expert Bruce Grant of the College of William and Mary in Williamsburg, Virginia, who points out that the evidence for natural selection in the moths was firmly in place long before Kettlewell came along with his vivid photographs.


    Caught in the act.


    Surprising—and unwelcome—customers have been taking advantage of Japan's high-speed optical fiber communications services. Cicadas have been laying eggs in the cables, which connect homes to main lines, cutting the optical fibers in the process.

    Astonished engineers at Nippon Telegraph and Telephone Corp. (NTT) have blamed the loss of service—more than 1000 cases last year—on an infestation of Cryptotympana facialis, known as “kumazemi” or “bear cicada.” Hideharu Numata, an entomologist at Osaka City University who is advising the phone company, says 7-centimeter-long kumazemi are proliferating in urban areas. The fiber-optic cables are “a little thinner than the preferred dead twigs but still okay” from the bugs' perspective, he says, adding that the hair-thin optical fibers sheathed in soft polyethylene sleeves are no match for the bug's tough millimeter-wide, centimeter-long ovipositor.

    NTT has improved shielding on its new cables and is trying a polyurethane coating thought to be more like the bark of a live twig, which the cicadas avoid. “It's not clear yet whether this problem can be so easily fixed,” Numata says.

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