Wednesday, January 29, 2014

My Year of Darwin (1/29/2014)

 Charles Darwin

"These animals [octopi] also escape detection by a very extraordinary, chameleon-like power of changing their colour" -Charles Darwin,Voyage of the Beagle

Darwin is remarking on the ability of cephalopods to match their backgrounds or to contrast with it. Darwin watched on octopus moving like it was stalking him and it was changing colors as it moved across the tide pool. Question is, does the octopus need to see the back group to match or can the skin see the background. The latter hypothesis may seem absurd but animals, including vertebrates, have molecules in the skin that are related to the photosensitive molecules (rhodopsins) in the eye. The contrasting color was used when the octopus was poked.

Here's a BBC video of an example of adaptive camouflage

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