20 January 2009
Early farmers bred different coloured animals for their own amusement
Early farmers may have genetically altered the coats of domestic animals for their own amusement, creating spots and stripes in the process, scientists believe. The results of their experiments can be seen in animals with patterns or colours that are far removed from those of their wild ancestors. The changes, made by selective breeding, affected one of the genes that control coat colour.
A study of wild and domestic pigs published in the online journal Public Library of Science Genetics showed how the genetic alterations occurred over thousands of years. One possible reason for changing the coat colour of livestock was to keep track of animals whose camouflage would otherwise make them hard to see, said the scientists. Another may have been to mark out animals with improved characteristics over their ancestors. Alternatively, it may have just been done for fun. "A third possibility is that the early farmers were as amused and as taken with biological novelty and diversity as we are today," said Dr GregerLarson, one of the scientists from the University of Durham.
The researchers found that DNA mutations were common in both wild and domestic pigs. But in wild pigs, none of them altered melanocortin-1 MC1R or their uniform black-brown highly camouflaged coat. Coat colour changes would have made these animals more vulnerable to predators, and likely to be selected out. In the case of domestic pigs, nearly all the observed mutations altered MC1R. Sometimes there were three layered mutations, indicating that the initial changes had been in existence for a long time. This was evidence that the mutations and resulting coat colour changes were actively encouraged and perpetuated by farmers over thousands of years.
Dr Larson said: "The Mesopotamians had different-coloured farm animals 5,000 years ago and, in that regard, they were no different to Paris Hilton, who has a pink Chihuahua, or anyone else with animals with unusual coat colours. This study demonstrates that the human penchant for novelty stretches back thousands of years."
Source: Telegraph.co.uk (15 January 2009)
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