China is in mourning after its most famous and oldest captive (圈养的) panda Basi died 【小题1】(age) thirty-seven. Basi was born in the wild in 1980. At the age of four, she fell into an icy river and was 【小题2】(fortune) rescued by some local villagers 【小题3】(live) in the county of Baoxing in southwest China's Sichuan Province. The locals handed her over to the Strait Panda Research and Exchange Centre in Fuzhou, where she lived the rest of her life. Basi came to fame shortly【小题4】she was chosen as the model for Pan Pan, the mascot of the 1990 Asian Games in Beijing.

Basi never bred (繁殖) but overcame several severe【小题5】(ill) to live for more than【小题6】(two) the 15-year life expectancy of wild pandas. Basi【小题7】(confirm) to be the world’s oldest captive panda by Guinness World Records in August. Captive pandas tend to live【小题8】(long) due to better nutrition and living conditions. Word has come【小题9】Basi’s body will be put in Basi Museum, which is【小题10】construction at present for people to remember her forever and share the spirit of the harmonious development between humans and nature.

In August 2014, paleoanthropologist (古人类学家)Yingqi Zhang and his team went down into a sinkhole on the hunt for Gigantopithecus, the largest known primate(灵长类动物)to ever live. They came back out with a mix of bones from the unfortunate 【小题1】 (creature) that had fallen into the natural "death trap". None of those bones belonged to the extinct ape, but the team was in for a surprise: The mix included a 22,000-year-old lower jaw from 【小题2】ancient panda. And within its worn edges, the jaw contained 【小题3】 is now the world’s oldest sample of panda DNA. Moreover, the genetic evidence 【小题4】(show) that the bone comes from a 【小题5】(previous) unknown lineage of giant panda. This animal may have been specifically adapted to【小题6】(live) in its subtropical home, suggesting that the black-and-white beasts were once much 【小题7】(diverse) than they are today, the authors argue in a paper 【小题8】 (publish) in the journal Current Biology. While the 【小题9】 (conclude) about panda diversity is probably not revolutionary, the team's work collecting ancient DNA from the degraded fossils is 【小题10】 great significance.

Are Bamboo-Eating Pandas Really Herbivores?

On the outside, giant pandas look like herbivores (食草动物). They spend nearly all of their waking hours 【小题1】 (eat) bamboo. But on the inside, they’re built like carnivores (食肉动物). About half of the calories they eat come from protein, according to a new study.

The ancestor of giant pandas were omnivorous (杂食的). They ate both animals and plants, and had the digestive system and gut bacteria to metabolize (使发生新陈代谢) them. They had “umami taste receptors,” to appreciate the flavors of meat.

However, about 2.4 million years ago, things began to change. The gene for their “umami taste receptors” became 【小题2】 (active). Their jaw and teeth evolved to help them crush bamboo, and their wrist bone became capable of grasping the stalks (秆) of their favorite plant. Scientists think pandas switched to eating bamboo partly 【小题3】 they didn’t have to fight with other animals to get it. Bamboo is high in fiber but has a low concentration of nutrients, so pandas 【小题4】 eat 20 to 40 pounds of the plant every day just to get by.

David Raubenheimer, a nutritional ecologist at the University of Sydney, and his colleagues put GPS trackers on two giant pandas and followed their movements throughout the year. They discovered that the pandas followed the protein. Between August and April, they【小题5】 (seek) food in low elevations (海拔) on China’s Qinling Mountains. At the start of the cycle, they ate Bashania fargesii leaves 【小题6】 they got the chance to feast on young shoots, which contained more protein.

The more the shoots grew, the more their protein was diluted (冲淡) by fiber. That caused the pandas to move to higher ground, 【小题7】 Fargesia qinlingensis grew. First, they ate the shoots, but these, too, went from being protein-rich to fiber-rich as they grew. The pandas responded by switching to the leaves. They fed 【小题8】 them until they went back down the mountain and started eating Bashania fargesii leaves again. The researchers found that about half of the calories the pandas ate were in the form of protein.

Scientists think the research shows that pandas are very clever. “They can know exactly where to go, and when to go, so they can get the most of the nutrients 【小题9】 their ecosystem can provide,” said Silvia Pineda-Munoz, who was not involved in the study.

The work also shows that classifying an animal as herbivore or carnivore is more complex than one might assume. “It’s not 【小题10】 you’re eating plants but what part of the plants you’re eating,” said Pineda-Munoz.