《考研英語(yǔ)閱讀理解100篇 高分版》 Unit 24 - TEXT THREE

In the case of equal rights, feminists have had much to complain about. But one striking piece of inequality has been conveniently overlooked: lifespan. In this area, women have the upper hand. All round the world, they live longer than men. Why they should do so is not immediately obvious. But the same is true in many other species. From lions to antelope and from sea lions to deer, males, for some reason, simply can't go the distance. One theory is that males must compete for female attention. That means evolution is busy selecting for antlers, aggression and alloy wheels in males, at the expense of longevity. Females are not subject to such pressures. If this theory is correct, the effect will be especially noticeable in those species where males compete for the attention of lots of females. Conversely, it will be reduced or absent where they do not.
To test that idea, Tim Clutton-Brock of Cambridge University and Kavita Isvaran of the Indian Institute of Science in Bengalooru decided to compare monogamous and polygynous species (in the latter, a male monopolises a number of females). They wanted to find out whether polygynous males had lower survival rates and aged faster than those of monogamous species. To do so, they collected the relevant data for 35 species of long-lived birds and mammals.
As they report, the pattern was much as they expected. In 16 of the 19 polygynous species in their sample, males of all ages were much more likely to die during any given period than were females. Furthermore, the older they got, the bigger the mortality gap became. In other words, they aged faster. Males from monogamous species did not show these patterns. The point about polygyny is that if one male has exclusive access to, say, ten females, another nine males will be waiting to topple the harem master as soon as he shows the first sign of weakness. The intense competitive pressure means that individuals who succeed put all their efforts into one or two breeding seasons.
That obviously takes its toll directly. But a more subtle effect may also be at work. Most students of ageing agree that an animal's maximum lifespan is set by how long it can reasonably expect to escape predation, disease, accident and damaging aggression by others of its kind. If it will be killed quickly anyway, there is not much reason for evolution to divert scarce resources into keeping the machine in tip-top condition. Those resources should, instead, be devoted to reproduction. And the more threatening the outside world is, the shorter the maximum lifespan should be.
There is no reason why that logic should not work between the sexes as well as between species. The test is to identify a species that has made its environment so safe that most of its members die of old age, and see if the difference continues to exist. Fortunately, there is such a species: man. Dr. Clutton-Brock reckons that the sex difference in both human rates of ageing and in the usual age of death is an indicator that polygyny was the rule in humanity's evolutionary past—as it still is, in some places. That may not please some feminists, but it could be the price women have paid for outliving their menfolk.
1. The passage is mainly discussing about _____.
[A] difference in life span between males and females of different species
[B] difference in life span among species of different mating patterns
[C] the reason of why human females outlive their male counterparts
[D] natural selection among males and females during evolution
2. In the sentence “That means evolution is busy selecting for antlers, aggression and alloy wheels in males...” (Paragraph 1), “antlers, agression and alloy wheels” represent _____.
[A] the most excellent males
[B] the most powerful males
[C] the most attractive males
[D] the most aggressive males
3. Which one of the following statements is TRUE of points proved by the test of Tim Clutton-Brock and Kavita Isvaran?
[A] Polygynous species have shorter life spans than monogamous species.
[B] Polygynous species aged faster than monogamous species.
[C] Polygynous males decrease faster in number as they grow older.
[D] Monogamous males live as long as their females.
4. The logic behind the fact that the species living in the most dangerous environment have the shortest life span is that _____.
[A] resources should be devoted to reproduction rather than sustaining life
[B] resources should be used most efficiently
[C] species in the most dangerous environment should not waste the resources
[D] there is no need to divert scarce resources into keeping the machine in best condition
5. The test conducted by Tim Clutton-Brock and Kavita Isvaran demonstrates that _____.
[A] polygyny was the rule in humanity's evolutionary past
[B] the sex difference on life span is attributable to humans' biological past which should not be denied by feminists
[C] the logic does not work between the sexes as well as between species
[D] it was polygyny that accounts for human females' general longevity over males