Zebra stripes may have evolved to keep biting flies at bay...

The headline on this BBC article reads, "Zebra stripes evolved to keep biting flies at bay". It's an interesting piece about a study undertaken by Hungarian and Swedish scientists who measured the attractiveness of certain colours and patterns to biting flies. They began by painting boards different colours, then they left those boards coated with a sticky substance in a field. After a set time they counted the flies stuck to each board.

The black and brown boards turned out to be the ones with the most flies stuck to them, with the lighter boards attracting the fewest flies. What came as a surprise was that the boards with zebra stripes attracted even fewer flies than the white boards. This they deduced was because of the light wave formation reflected by the different boards and detected by the flies. They repeated the experiment but with painted horse models covered in a sticky substance with much the same result.

However, it seems that the scientists did not say, "Zebra stripes evolved to keep biting flies at bay". No. And in the BBC report Prof Matthew Cobb, an evolutionary biologist from the University of Manchester, pointed out that the experiment did not exclude the other hypotheses about the origin of zebras' stripes". He went on to say, "Above all, for this explanation to be true, the authors would have to show that tabanid fly bites are a major selection pressure on zebras, but not on horses and donkeys found elsewhere in the world... none of which are stripy,"

And despite all this the BBC went with the headline, "Zebra stripes evolved to keep biting flies at bay". Who was it who once asked, "Why let the facts stand in the way of a good story?"