Tortoise's Long-Distance Call
The Galapagos Islands off the coast of Ecuador helped inspire Charles Darwin's renowned theory of evolution.
The islands are home to some of the world's most exotic creatures, including the giant Galapagos tortoise, which can grow to up to five feet long and weigh up to 650 pounds, making it the world's largest living tortoise.
Only one male of one subspecies of the tortoise remains alive today.
Conservation scientists have been trying to mate him with females from the islands closest to his to keep the subspecies alive. But "Lonesome George" has never shown any interest. Now, researchers think they know why.
An international team of scientists from Yale University in New Haven, Conn., the State University of New York in Syracuse and the University of Rome in Italy analyzed the genes of tortoise species around the world. To their surprise, the researchers found that George is more closely related to tortoises found on the islands of Espanola and San Cristobal, which are farthest from George's original home island of Pinta.
"This finding may provide guidance in finding a mate for Lonesome George, who so far has failed to reproduce," the researchers wrote in the Nov. 9 issue of the Proceedings of the National Academy of Sciences.
Weather Helped Doom Explorer
In 1912, Robert Falcon Scott led a British expedition on an arduous 900-mile trek to the South Pole, only to be beaten to his goal by a competing Norwegian group led by Roald Amundsen. Scott and two remaining companions perished in the harsh conditions trying to get back home.
Historians have blamed a variety of factors for Scott's demise, including his using ponies instead of sled dogs, lack of experience with skis, vitamin deficiencies and blizzards.
New research indicates that the weather was unusually harsh--even by Antarctic standards--during Scott's doomed adventure, and may have played even a greater role in his demise than previously appreciated.
Susan Solomon of the National Oceanic and Atmospheric Administration in Boulder, Colo., and Charles R. Stearns of the University of Wisconsin in Madison analyzed data gathered from the pole using automated weather stations for more than a decade. They discovered that temperatures that Scott reported--below minus 30 degrees Fahrenheit on average--were 10 to 20 degrees below those usually recorded during that time of year.
"These remarkably cold temperatures likely contributed substantially to the exhaustion and frostbite Scott and his companions endured, and their deaths were therefore due, at least in part, to the unusual weather conditions they endured during their cold march across the Ross Ice Shelf of Antarctica," they wrote in the Nov. 9 issue of the Proceedings of the National Academy of Sciences.
Motherhood, Memory Enhancer
Having a baby may wreak havoc on a female's body, but it may improve her memory.
Craig H. Kinsley of the University of Richmond and colleagues conducted a series of experiments with rats, comparing how virgin and maternal rats did remembering how to find their way through mazes. Overall, the mothers did much better.
"When a female mammal makes the transition from virginity to motherhood, she is forced to refocus her activities dramatically. She must adapt to a multitude of new demands by her offspring or risk losing a significant metabolic and genetic investment," they wrote in the Nov. 11 issue of Nature.
Monkeys' Social Inhibitions
Everybody knows that monkeys can see no evil, speak no evil and hear no evil. New research shows that monkeys can also play dumb.
Christine M. Drea and Kim Wallen of the Yerkes Regional Primate Research Center at Emory University in Atlanta tested 38 female and 17 male rhesus monkeys to determine whether they behaved differently individually from how they behaved in group settings.
Monkeys from "dominant" families performed best under all circumstances, whereas those from "subordinate" families showed what they knew only when none of the dominant monkeys were around.
"We present a case of 'playing dumb' in monkeys, similar to that in humans, in which a specific social setting promoted the voluntary inhibition of performance," the researchers wrote in the Oct. 26 Proceedings of the National Academy of Sciences. "Our results could be analogous to circumstances in humans where competent individuals inhibit academic or athletic performance as a result of social status, gender, or racial influences."
CAPTION: Galapagos Islands' Lonesome George has no mate.