The extra feathers don't appear to serve any particular function, but to people they can certainly look snazzy and often appeal to bird breeders.
The scientists analyzed DNA from the chickens and identified the location on a chromosome that is associated with the unique traits. Guo and his team next sequenced that region from chickens both with and without beards.
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The researchers found that chickens with beards have three duplicated regions of a chromosome called 27. One of the duplicates, HOXB8, is a gene known to function in feather development. It was present at high levels in the facial skin of chickens with beards, but not in the other chickens included in the study.
Prior research has linked this same gene in other animals to everything from compulsive grooming in mice to colon cancer in humans. While this latest study just focused on one novel trait in chickens, the findings reveal more about genetic variation, which is key to the evolution and development of every animal. As the researchers wrote, "The chicken is an attractive avian species for genetics research ..."
In this case, the bearded chickens were attractive in all respects.
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