The giant panda's coloration may stem from its poor diet

題材文章詞數(shù)動(dòng)物404 難度 ★★★體裁建議用時(shí)說明文7 min

難詞探意

1. predator /'pred?t?(r)/ n. 捕食性動(dòng)物

2. camouflage /'k?m?flɑ??/ n. 偽裝

3. hibernate /'ha?b?ne?t/ v. 冬眠

4. compromise /'k?mpr?ma?z/ n. 妥協(xié)；折中；讓步；和解

Tim Caro，Professor of Wildlife Biology at the University of California,Davis,has made it his duty to understand the evolution of color in mammals. The researcher spent twenty years investigating why zebras have black and white stripes and even wrote a book, Zebra Stripes, about his very great discovery. Now, Caro has solved the age-old mystery of why giant pandas also have the double color. According to the researcher, understanding why the giant panda has such striking coloration has been a long-standing problem in biology that has been difficult to solve because virtually no other mammal has this appearance,making comparisons difficult.

Over the years，there have been numerous theories to explain the animal's black and white color. Some experts thought that it was to scarepredators. Others believed that the white fur provided the mammal with much-neededcamouflagein the snow, while the dark fur enabled it to keep heat. There was also the theory that the markings on the panda's head kept it hidden from predators, while the dark circles around its eyes helped reduce the sun's glare.

To solve the mystery once and for all, the UC Davis team compared the coloring of different parts of the giant panda's body to those of 200 flesh-eating species. They discovered that different parts of the giant panda's coloring serve different purposes. As had been previously believed, the mammal's white face, neck,belly, and rump, allow it to blend in with the snow during winter. Its black arms and legs are not to keep heat，but to help it stay hidden in the shade during summer. This is particularly important for panda babies that are often in treetops and need to protect themselves from predators. The dark ears help scare off predators, while the black eye parts most likely enable giant pandas to recognize each other and， possibly, show aggression towards competitors.

According to the study, the giant panda's striking double coloring may have to do with its poor diet that mainly consists of bamboo, which has little nutrition. Since the mammals are unable to build up enough fat reserves to allow them tohibernateduring the winter, they have no choice but to wander all year round in search of food.

The scientists guess that instead of developing a summer and winter coat similar to those of small flesh-eating animals, it has evolved acompromisewhite and black fur.

Reading Check

1. What is the second paragraph mainly about?

A. Different ideas about the giant panda's color.

B. How the giant panda's unusual color formed.

C. What Tim Caro discovered about the giant panda.

D. The evolution of color in the giant panda.

2. Why are the giant panda's arms and legs black?

A. To make it different from other mammals.

B. To avoid being seen by predators.

C. To keep warm in winter.

D. To make enemies afraid.

3. What might be the reason for the giant panda's color?

A. Oversleeping. B. Too much fat.

C. Unhealthy diet. D. Lack of activities.

Language Study

Sentence for writing

Tim Caro, Professor of Wildlife Biology at the University of California, Davis, has made it his duty to understand the evolution of color in mammals.

【信息提取】make it one's duty to do... 意為“把……當(dāng)作某人的責(zé)任”，句中的it為形式賓語(yǔ)，用來代替真正的賓語(yǔ)——?jiǎng)釉~不定式。

【句式仿寫】他把教育遙遠(yuǎn)山區(qū)的孩子當(dāng)作自己的責(zé)任。