科学美国人60秒 SSS Color-Changing Skin Aids Climate Control and Communication
时间：2019-01-20 作者：英语课 分类：2016年Scientific American(九)月
Various animals evolved coloration that keeps them hidden. A jaguar's patterns help it slink undetected across the sun-dappled rainforest floor. The mottled pigmentation on the wings of some let them rest on tree bark undisturbed. And then there are animals that can quickly change their appearance—for example, the Central Bearded Dragon.
This two-foot-long lizard 1 lives in the more arid 2 parts of Australia.
"They can change color really quickly, just in a matter of seconds or minutes.”
University of Melbourne biologist Katie Smith.
“And they do this by moving pigments 3 within specialized 4 skin cells called chromatophores."
Bearded dragons modify their colors for camouflage 5, or to maintain their body temperature, or to communicate with other dragons. Smith wanted to know how they meet all those needs with the same tool kit 6.
So she and her team rounded up twelve bearded dragons and put them through a series of tests before releasing them back into the wild. They found that when the dragons want to communicate with other members of their species, they change the colors on their neck.
"This is actually one of the reasons they're called bearded dragons—because they look like they have a really serious five o'clock shadow."
Changes to their backs were for temperature regulation. Shifting to yellow lets them to cool off during extreme heat, while darker greys allow them to soak up more heat during cooler weather.
"They actually save about, on average, 22 minutes a day at the darker colors than the lighter 7 colors. That's about 85 hours throughout the whole year."
Eighty-five hours a year NOT spent out in the open and exposed to potential predators 8. The results were published in the Proceedings 9 of the Royal Society: B. [Kathleen R. Smith, Viviana Cadena, John A. Endler, Warren P. Porter, Michael R. Kearney, & Devi Stuart-Fox. Colour change on different body regions provides thermal 10 and signalling advantages in bearded dragon lizards 11.]
The lizards can clearly control each part of their body separately, resulting in an efficient system. Temperature regulation involves the back, which is facing the sun. Social signaling uses the neck, easily visible to another lizard they’re faced off with.
The researchers' next task is to see what happens when the lizards have to deal with simultaneous but conflicting coloration requirements—situations that could give a bearded dragon a close shave.
—Jason G. Goldman
- A chameleon is a kind of lizard.变色龙是一种蜥蜴。
- The lizard darted out its tongue at the insect.蜥蜴伸出舌头去吃小昆虫。
- These trees will shield off arid winds and protect the fields.这些树能挡住旱风,保护农田。
- There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
- The Romans used natural pigments on their fabrics and walls. 古罗马人在织物和墙壁上使用天然颜料。 来自辞典例句
- The original white lead pigments have oxidized and turned black. 最初的白色铅质颜料氧化后变成了黑色。 来自辞典例句
- There are many specialized agencies in the United Nations.联合国有许多专门机构。
- These tools are very specialized.这些是专用工具。
- The white fur of the polar bear is a natural camouflage.北极熊身上的白色的浓密软毛是一种天然的伪装。
- The animal's markings provide effective camouflage.这种动物身上的斑纹是很有效的伪装。
- The kit consisted of about twenty cosmetic items.整套工具包括大约20种化妆用品。
- The captain wants to inspect your kit.船长想检查你的行装。
- The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
- The lighter works off the car battery.引燃器利用汽车蓄电池打火。
- birds and their earthbound predators 鸟和地面上捕食它们的动物
- The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》
- He was released on bail pending committal proceedings. 他交保获释正在候审。
- to initiate legal proceedings against sb 对某人提起诉讼
- They will build another thermal power station.他们要另外建一座热能发电站。
- Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。