chicot60
02-11-2012, 02:03 AM
Debra Black
http://i.thestar.com/images/be/f3/f12afa0a4f1fa4669e8de5165ba4.jpg
How did the zebra get its stripes?
A team of researchers from Hungary and Sweden think they have the answer. It has to do with evolution and a way to prevent blood-sucking disease carrying insects from attacking.
In a study, published in the Journal of Experimental Biology, Susanne Åkesson, an evolutionary ecologist and professor in animal ecology at Sweden’s Lund University, and a team of researchers found that a “striped (white) pattern” doesn’t attract as many horseflies as a black surface does.
The team of researchers used a horse model with zebra-like stripes in their study to measure the way light is reflected on a black surface compared to a white surface. They found the black surface reflects linearly polarized light in just the same way as a water surface.
“But if the black area is divided in more narrow bands with white stripes in between,” Åkesson wrote in an email to the Star, “this signal is destroyed in such a way that the horseflies (or tabanids) are not attracted.”
It seems the striped pattern is a more efficient way of reducing the risk of being attacked by flies,” Åkesson said.
Åkesson and her colleagues believe “the zebra seems to have evolved a stripe width that is narrow enough to prevent tabanids to be attracted and in this way minimize the risk of being bitten by the flies and at that time avoid the risk of getting lethal and dangerous blood diseases.”
With the evolution of this black and white striped coat zebras have also been able to make sure they graze properly. Tabanids not only transmit blood diseases with their bites, Åkesson said, but they also can be very annoying and make it difficult to feed.
It’s not just zebras who are able to use stripes to their advantage to fend off insects, Åkesson said. She suggests people might also want to wear a striped T-shirt that mimics the zebra’s coat if they go to the lake in the summer and want to avoid being bitten by horseflies.
http://www.thestar.com/news/world/article/1129473--study-answers-how-the-zebra-got-its-stripes
http://i.thestar.com/images/be/f3/f12afa0a4f1fa4669e8de5165ba4.jpg
How did the zebra get its stripes?
A team of researchers from Hungary and Sweden think they have the answer. It has to do with evolution and a way to prevent blood-sucking disease carrying insects from attacking.
In a study, published in the Journal of Experimental Biology, Susanne Åkesson, an evolutionary ecologist and professor in animal ecology at Sweden’s Lund University, and a team of researchers found that a “striped (white) pattern” doesn’t attract as many horseflies as a black surface does.
The team of researchers used a horse model with zebra-like stripes in their study to measure the way light is reflected on a black surface compared to a white surface. They found the black surface reflects linearly polarized light in just the same way as a water surface.
“But if the black area is divided in more narrow bands with white stripes in between,” Åkesson wrote in an email to the Star, “this signal is destroyed in such a way that the horseflies (or tabanids) are not attracted.”
It seems the striped pattern is a more efficient way of reducing the risk of being attacked by flies,” Åkesson said.
Åkesson and her colleagues believe “the zebra seems to have evolved a stripe width that is narrow enough to prevent tabanids to be attracted and in this way minimize the risk of being bitten by the flies and at that time avoid the risk of getting lethal and dangerous blood diseases.”
With the evolution of this black and white striped coat zebras have also been able to make sure they graze properly. Tabanids not only transmit blood diseases with their bites, Åkesson said, but they also can be very annoying and make it difficult to feed.
It’s not just zebras who are able to use stripes to their advantage to fend off insects, Åkesson said. She suggests people might also want to wear a striped T-shirt that mimics the zebra’s coat if they go to the lake in the summer and want to avoid being bitten by horseflies.
http://www.thestar.com/news/world/article/1129473--study-answers-how-the-zebra-got-its-stripes