Elephants losing tusks
People killing elephants for their tusks has long been a problem worldwide. Although laws have been introduced to ban the selling of tusks, they have not been enough to save the elephants.
But the giant animals have now “developed” their own solution to stay safe from hunters----by not growing tusks at all.
Scientists found that among female African elephants, as many as 98 percent of them now have no tusks, reported The Independent newspaper. The number was 15 percent in 1998 and only 1 percent in 1930, according to the BBC.
But this solution has less been developed by elephants themselves, and more by evolution.
Evolution is all about natural selection（選擇）. When an environment changes, for example, animals and plants that can deal with the change will stay alive while others won’t. And for elephants, the change came when hunters started killing them for their tusks. As a result, elephants with big tusks couldn’t stay alive because hunters wanted to shoot them. Those born with tusks managed to stay alive and give their “tuskless” genes（基因）to their babies. As a result, more and more elephants are now being born without tusks.
But this solution, as effective（有效地）as it might be, is a high price to pay for elephants. Tusks are important and play a number of roles, especially for male elephants, including fighting with other males, lifting and digging things up.
This is why scientists hope there can be other ways to protect elephants against hunters. They believe that when they are less likely to be killed , elephants will be able to grow tusks again.
To David Cowdrey, head of Policy and Campaigns at the International Found for Animal Welfare UK, however, this is not very likely to happen in the near future.
“Unfortunately, it comes down to the markets,” he told The Guardian. “As long as people will pay high prices for products that come from endangered animal and plants, they’re going to have price on them and that causes the hunting.”
1.Which of the following is TRUE according to the passage?
A. Elephants learned to lift and dig things up without tusks.
B. Elephants chose not to grow tusks because of their dangerous environment.
C. Elephants with no tusks had a greater chance of passing down their genes.
D. A tuskless elephant gives birth to more baby elephants than an elephant with big tusks.
2.The underlined word “evolution” in paragraph 4 means “_________” ?
A. gradual change B. sudden development C. complete loss D. rapid growth
3.What can you learn from the last two paragraphs?
A. We should work out a better solution to protect elephants.
B. People should pay lower prices for products made with elephant tusks.
C. Elephants’ living environments will soon be improved.
D. The key to elephant protection is stopping the trade in tusk products.
1.B
2.A
3.D
【解析】短文大意：大象是一種瀕危動(dòng)物，由于象牙制品的買賣而導(dǎo)致大量的大象遭到捕殺。雖然已經(jīng)出臺(tái)法律禁止出售象牙，但它們還不足以拯救大象。大象也通過(guò)自身的進(jìn)化來(lái)拯救自己，那些長(zhǎng)著象牙的大象設(shè)法活下來(lái)，會(huì)把它們的“無(wú)牙”基因送給他們的孩子，結(jié)果越來(lái)越多的大象現(xiàn)在沒有牙齒就出生了，但是象牙對(duì)大象來(lái)說(shuō)非常重要，科學(xué)家們希望有其他的方法來(lái)保護(hù)大象不受獵人的攻擊。他們...
