Random Samples

Science  09 Jul 2010:
Vol. 329, Issue 5988, pp. 125

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  1. Out of the Ice


      Three years ago, Craig Lee spied what looked like a tree branch in a small water channel streaming from a melting ice patch high in the Rocky Mountains near Yellowstone National Park. Walking over for a better look, Lee, an archaeologist at the University of Colorado, Boulder, realized it was the 107-centimeter-long foreshaft of a wooden dart, shaped by an ancient hunter and later trampled by an animal and deformed by flowing slush. Now, radiocarbon dating has revealed that the weapon is 10,400 years old—the earliest artifact ever discovered melting out of ancient ice. “I was just flabbergasted,” says Lee, who presented the results at a meeting in April and is preparing a paper for publication.

      With global temperatures rising, archaeologists have collected hundreds of ancient artifacts melting out from alpine ice patches in Alaska, northern Canada, and Norway. By feeding data from satellite images and aerial photographs into a computerized geographical information system, Lee is identifying sites for finds much farther south in North America. His new find, says Canadian Yukon government archaeologist Greg Hare, shows that “the potential for ice-patch archaeology exists almost anywhere there is persistent snow cover.”

      Lee thinks a Paleoindian hunter lost the ancient dart while hunting bighorn sheep. The dart's icy grave was a boon. “Most of our archaeological record from this period consists of chipped stone artifacts,” he says. “The ice patches preserve organic materials, so they are giving us a huge window into more perishable technology.”

    1. Doom on the Moon


        You're an astronaut on a lunar base, and a meteorite knocks out the oxygen generator. You've got 20 minutes of air left. What to do?

        Click the mouse! You're playing Moonbase Alpha, a free, commercial-quality video game NASA released this week (http://bit.ly/moon-base). Graphics draw from engineers' models for future lunar habitats and rovers, says project manager Daniel Laughlin, an educator at the University of Maryland, Baltimore County. How does it rate as a game? “I'm a gamer, and plenty of times I've been gritting my teeth … in frustration,” Laughlin says. “That's what I tend to call hard fun.”

      1. Lucky Genes


          Finding the gene that makes four-leaf clovers has been as hard as spotting the lucky plants themselves. For one thing, white clover has two complete genomes, probably from two ancestors that hybridized to make the species. Plus, the four-leaf trait is recessive, and it's expressed more in some seasons than others.

          Now a team of researchers has pinned down the gene. Rebecca Tashiro, then a graduate student at the University of Georgia, Athens (UGA), crossed a plant that had been bred to make multipart leaves with another white clover, took tissue samples from the offspring, and checked their leaves. “Three years of looking for a four-leaf clover on 200, 400 plants each time, you get pretty good at spotting them,” says Tashiro, who mapped the four-leaf trait and others onto the genome. The map is published in the July–August issue of Crop Science.

          The new map should make it easier for other breeders to get the clover they want, says Tashiro. The map could also be relevant to alfalfa, clover's relative and a vital feed for livestock, says E. Charles Brummer, a plant breeder at UGA who did not work on the project. “Any time you learn something in clover, it's almost trivial to apply that to an alfalfa question,” he says. “It just helps fill in the whole puzzle.”

        1. Evolution for Bartenders


            While sipping a Bloody Mary at a party in graduate school, evolutionary biologist James Harriman had an idea. “Everyone has a different recipe for Bloody Marys, so there occur these little differences. Like someone says, ‘I want more hot sauce,’” he says. Harriman wondered whether such personal quirks evolve into popular cocktails much as mutations give rise to new species, through a sort of taste-based natural selection.

            So Harriman, now a visiting scientist at Cornell University, fired up a computer program for generating phylogenetic trees. Instead of genes, he plugged in the ingredients of 100 cocktails, taking vodka as the tree's common ancestor. The program divided cocktails into several distinct families—drinks based on champagne or Irish cream, for example, or punch bowl drinks—and served up a few surprises. A cocktail called 110 in the shade (lager and tequila) is “sort of the platypus of the drink family,” Harriman says, “because it has nothing in common with anything else.” A poster of the tree, which doubles as a mixology guide, is available online from ThinkGeek (www.thinkgeek.com).