Tarantulas evolved blue colour 'at least eight times'

Published: 28 November 2015

That is the conclusion of a study by US biologists, exploring how the colour is created in different tarantula species.
The hue is Caused by tiny structures inside the animals' hairs, but vary across Those shapes the family tree.
Sr. Hsuing of Ohio University, has a doctorate in science, says these tarantulas have the blue color to have had to evolve least eight times, have known geneologic doing a tree, forming one large and detached by one of the branches of the blue tarantula

The team also purchased specimens of eight tarantula species, and took a close look at those blue hairs.
They used electron microscopes to zoom in on tiny shapes within those hairs and conducted simulations of how those shapes could produce a "structural colour" by reflecting - very specifically - this wavelength of blue light
.
The results, again, pointed to the colour cropping up multiple times independently: several different types of shape could be seen, even on the same branch of the family tree.
"That's one of the reasons why it must have evolved so many times - because we don't see a very clear pattern of how these different mechanisms split," Mr Hsiung said.
"If we could see a clear split, then it might have evolved just one or two times. But it's all over the place.

"But if it's not for other tarantulas, then it must be to some other receivers out there."
It may be that this colour helps conceal the critters from their prey while they hunt at night; or perhaps it serves as a warning to stop the tarantulas themselves being eaten.
"We don't know yet," Mr Hsiung said.


Link: http://www.bbc.com/news/science-environment-34944735