It may not come as much of a surprise to dog-owners, but it seems that dogs and babies share similar logical abilities, as shown by a study published in Science.
Experimenters started out with a classic logic experiment, which goes like this: researchers hide a toy in location “A” multiple times while looking at a 10-month-old baby and talking to him (”Look, I have this nice ball!”). When asked to find the toy, the baby always goes to location “A.” The experimenter then hides the toy at location “B,” again while interacting with the baby. But this time, when asked to find the toy, the baby continues to search for it at location “A.” The findings hold, even when a team changes experimenters midtest. Researchers believe that infants make this error because they believe the adults have taught them something fundamental about the world (i.e., “Your toy will always be at location ‘A’”) [ScienceNow].
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Scientists trying to determine where dogs were first domesticated have been sent back to the drawing board by a new study. Back in 2002, researchers sampled DNA from dogs around the world, and determined that dogs in East Asia had the most genetic diversity, suggesting that the species originated there and that dogs in that region have had the longest time to evolve. But the new study suggests that those earlier results were skewed, because DNA sampling of African street dogs has revealed equal genetic diversity.
The earlier findings may have been thrown off because the large-scale study included both purebred dogs, whose evolution has been closely guided by human hands, and street dogs, who have bred more autonomously and randomly, and who therefore show more genetic diversity. But the 2002 researchers drew DNA from different types of dogs in different regions. Says Adam Boyko, lead researcher of the new study: “I think it means that the conclusion that was drawn before might have been premature. It’s a consequence of having a lot of street dogs from East Asia that were sampled, compared to elsewhere” [BBC News].
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On the steppes of Central Asia, researchers have found evidence of the earliest “horse farm” dating from 5,500 years ago, pushing back the known domestication of horses by 1,000 years. Those first domesticated horses were probably kept primarily for meat and milk, researchers say, but soon enough new uses emerged, and horse riding revolutionized transport, communications, trade, and warfare. Says study coauthor Sandra Olsen: “To me, the domestication of the horse was a seminal event in human history…. All the major empire builders, like Alexander the Great and Genghis Khan, would have been nothing without horses” [Los Angeles Times].
The evidence of the early farm developed by the ancient Botai people of present-day Kazakhstan includes massive deposits of horse bones, grooved horse teeth that indicate the animals wore bridles, and even the chemical traces of horse milk fats in ceramic pots, says study coauthor Alan Outram. “This is, apart from being fascinating, something of a smoking gun for domestication — would you milk a wild horse?” said Outram [AP]. The people of Kazakhstan and Mongolia still milk mares today to make a fermented, slightly alcoholic drink called “koumiss.”
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Thousands of years ago a few bold wolves moved into a human encampment, and human lives have been richer ever since. But a new study shows that domesticated dogs gave something back to their wild cousins. A genetic analysis has revealed that the dark black coats common among wolves living in North America arose through wolves mating with dogs, who already had dark fur.
The finding presents a rare instance in which a genetic mutation from a domesticated animal has benefited wild animals by enriching their “genetic legacy.” … Because black wolves are more common in forested areas than on the tundra, the researchers concluded that melanism — the pigmentation that resulted from the mutation — must give those animals an adaptive advantage [The New York Times]. But what that advantage may be remains something of a mystery.
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