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  • What's up with the color color colors of Chameeeleons, they come and go. They come and go! Changing

  • color is a rarity in the animal world, and also a mystery, until now!

  • Hey everybody thank you for watching DNews today. I'm Trace and I am right here on our

  • brand new set!

  • Chameleons change color so well, and are so well known across the planet for doing so,

  • that their name is synonymous with someone who is good at changing their look, behavior

  • or opinions as their situation changes. Most people think chameleons change color for camouflage,

  • but that's not it at all! Only the males can change color, and they do so to communicate

  • danger to other nearby chameleons, or for a mating display. Ladies. *wink*

  • It's a pretty dramatic show when a chameleon swaps its green for bright red, and thanks

  • to new research, we now know HOW they do it. Researchers from the University of Geneva

  • looked at the skin cells of chameleons to observe how they change color. Within their

  • skin, it turns out, chameleons have cells called iridophores. Suspended within those

  • cells are tiny guanine nanocrystals which are formed into a lattice. When relaxed, the

  • chameleonsiridophore lattices are contracted, and mainly reflect blue light, but when excited

  • the chameleon expands and three dimensional lattices expand along with them, reflecting

  • different wavelengths of light! Below that layer, there's a layer of skin with even larger

  • nanocrystals which reflect near-infrared light; providing "passive thermal protection." Which

  • is great, because these cold-blooded animals can't change their body temperature; changing

  • that base layer may be one way they can affect how much near-infrared light, and therefore

  • heat, is absorbed into their body,.

  • Camouflage is also called cryptic coloration; or a color and pattern that makes an animal

  • difficult to discern from its surroundings; concealing it. The ability to CHANGE colors

  • isn't unique to chameleons -- some fish, frogs, insects, crustaceans, cephalopods, and other

  • lizards can do it too, but they don't have nanocrystalsthis research is the first

  • time that's been seen in reptiles. And other animals use different methods of color shifting.

  • Cuttlefish, for example, can also change their colors at will; but rather than crystal-filled

  • iridophores, they use chromatophores. Chromatophores are sacs of a single pigment of color surrounded

  • by muscle. The cuttlefish has learned to widen or constrict that sac to show more or less

  • of that color. Invertebrates like cephalopods use these chromatophores too, and for more

  • on that you can check out our video exploring how the disco clam can reflect light like

  • a disco ball!

  • Over time, evolution, mutation and simply breeding with others can cause changes in

  • the colors of species, humans included -- all blue-eyed humans descend from a single mutated

  • ancestor. Usually because those animals which have these colorful adaptations tend to survive

  • better. Zebra stripes confuse predatory eyes, helping to disguise individuals and making

  • the herd look more massive; background matching camouflage helps both predators like tigers

  • blend with their environment; as well as helping their prey hide by resembling it's surroundings

  • but these adaptations take many generations to develop! Active color change is pretty

  • rare in the Animal Kingdom. Before this research, scientists believed chameleons changed color

  • the same as cuttlefish or octopuses, but once they put the skin cells into a super-magnifying

  • electron microscope, they were able to see this unique and super cool system for reflecting

  • light!

  • How do you think humans camouflage into our surroundings? Do we? Why or why not...

What's up with the color color colors of Chameeeleons, they come and go. They come and go! Changing

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カメレオンはどうやって色を変えるのか? (How Do Chameleons Change Colors?)

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    羅紹桀 に公開 2021 年 01 月 14 日
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