Cats, which have lived alongside people for thousands of years, have adapted their "meows" to better communicate with humans, according to Nicholas Nicastro and Michael Owren of Cornell University's Psychology of Voice and Sound Laboratory. "Cats are obviously very dependent on people for their needs," says Nicastro. "I think cats have evolved to become better at managing and manipulating people."
One way they are trying to prove this is by analyzing a range of vocalizations of domestic cats and then screening people's reactions to them. To compare their results, they are doing the same thing with the calls of wild cats.
Nicastro recorded more than 100 different meows from 12 domestic cats (including two of his own). He solicited various sounds from the cats by placing them in different situations, such as waiting beyond feeding time before feeding them, putting them in empty rooms with the recorder and waiting. He had the owners brush the cats beyond the animals' patience for brushing. And, to record content meows, he simply turned on the recorder "when they were in a good mood."
He then played the recordings to two sets of people. He asked the first group of 26 people to rate each meow in terms of how pleasant it sounded. The second group of 28 people was asked to rate each sound in terms of urgency. When he compared people's ratings with acoustical analysis of the meows, he found very clear patterns.
The meows that were rated most pleasant were shorter in duration, had higher frequencies and tended to change from high to low notes. Those rated most urgent were longer in duration, had lower frequencies and often began on low notes and escalated to higher ones. Rarely did a meow receive high marks for both pleasant and urgent.
"The highly urgent calls tended to be the least pleasant-sounding and the highly pleasant ones seemed to be rated not so urgent," he says. Nicastro suggests that cats may have developed different kinds of calls to "hook into human perception tendencies" and alert us of their mood and needs.
Records from ancient Egypt suggest that bonds between cats and people date at least as far back as 5,500 years ago when Egyptians began domesticating wild cats. The animals quickly became treasured pets and were honored in artwork for their snake- and mice-hunting skills. By 1500 B.C., Egyptians began regarding cats as sacred and it became a crime, punishable by death, to kill one.
Today, about 90 million cats are kept as house pets in the United States alone. Nicastro points out that since cats have shorter life spans than people, they've had many more generations to evolve ways of manipulating their owners through their calls.
The suggestion of a co-evolution between people and domesticated animals is not new. Other studies have found that dogs are highly skilled at following the gaze of people (possibly to spot food). While researchers say it's possible that cats may have evolved in order to better communicate with people, they caution it's easy to jump to conclusions."It's conceivable they developed ways to communicate with people since they've interacted with people for so many years," says Douglas Nelson, a professor of bioacoustics at Ohio State University. "But the cats could also have evolved different calls to communicate with each other."
To help prove a possible human influence on the domestic cat, Nicastro went to a zoo in Pretoria, South Africa, and recorded the calls of wild desert cats (the animals thought to be the ancestors of domestic cats). He's still analyzing the sounds and plans to have people screen them, but his preliminary findings reveal very different vocalizations."They're much harsher and far less musical-sounding than domestic cats," Nicastro says. "When I've played the sounds for other people, they think they're leopards. They say they sound like cats on steroids."
Nicastro says, "We probably know more about obscure monkeys in Africa than we know about the animals hanging out in our own kitchens."
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Honeybees could be the latest fighters in the U.S. war on terror, says the Pentagon. The government is hoping to use the bees to "sniff out" even minute residues of explosives, so they can find hidden bomb factories and landmines.
Bees appear even better able than dogs to detect particular odors, and they roam large distances from the hive in search of food. One option under consideration is to place a trained hive near security checkpoints to raise the alert should a bomber try to cross.
Scientists already know that bee behavior can be conditioned by rewards such as sugar-water. Combining the scent of the sugar solution with tiny residues of TNT means that bees will associate the "molecular trail" of TNT with food. When a bee carrying this information returns to the hive, it will pass the knowledge of the scent and its location to thousands of other bees.
Pentagon scientists have already succeeded in persuading bees to swarm around explosives - even in preference to flowers. After training, this happens 99% of the time. They can track the insects by attaching a tiny radio transmitter to certain individuals.
Richard Jones, the director of the International Bee Research Association in Cardiff, Wales, says, "It's quite possible. You can train a bee. If you put sugar-water outside your window at a certain time each morning, the bees will come back every day - but only at that time. So if you mixed the sugar-water with a hint of TNT, you would condition them to hunt for TNT. However, bees are pretty damn lazy, really. If there is something else more tempting on offer, they will go for that instead. They will go for the nearest source of food.?
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A Taiwanese company has created a genetically modified zebra fish so they will glow in the dark. A jellyfish gene has been added to make them glow yellow-green. They are the first ornamental fish which have been genetically modified.
The GM Medaka or zebra fish - an east Asian freshwater variety - has been developed by Taiwan's Taikong Corporation. It?s called the TK-1. The company insists the TK-1 is safe, sterile and the fluorescent gene is not harmful.
But aquatic industry specialists are worried that the TK-1 could colonize British waters if they escaped. "Piranhas that could survive in our waterways would be a major problem," says Derek Lambert, the editor of Today's Fishkeeper magazine, who is urging buyers to boycott the TK-1. "We are worried about Frankenstein fish."
If your fish dinner glows by candlelight, you?ll know the gene has spread.
If you want to be able to communicate better with your pet, read ?Is Your Pet Psychic?? by Richard Webster, click here.
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