為什么女性比男性更長壽?
文章來源:未知 文章作者:enread 發布時間:2020-04-26 09:17 字體: [ ]  進入論壇
(單詞翻譯:雙擊或拖選)
研究人員已經知道,全球各地的女性壽命都比男性長?茖W家們認為,男女預期壽命差異很大程度上與生物學上的生存因素有關。
Researchers already know that women live longer than men in all parts of the world. Scientists have largely linked the difference in life expectancy1 between the sexes to biological survival factors.
Now, a new study of wild mammals has found great differences in length of life and aging in many species of mammals.
The researchers found that, in humans, women live almost 8 percent longer than men. But among wild mammals, females in 60 percent of the studied species live, on average, 18.6 percent longer. The percentages are very different for different groups of mammals.
Jean-Francois Lemaitre led the study. He is from the University Lyon 1 in France. He and his research team collected information on age-related deaths for 134 groups of 101 wild species of mammals.
Lemaitre said, "It was surprising to observe that this gender2 gap in lifespan often exceeds the one observed in humans and is, at the same time, extremely variable across species."
Tamás Székely, from the University of Bath, was one of the writers of the study. He told VOA that female lions in the wild live at least 50 percent longer than male lions.
"We previously3 thought this was mostly due to sexual selection, he said. "However our data do not support this."
Scientists say the risk of death does not increase more quickly in males than in females across species. They say there must be other, more complex reasons. These include things such as environmental conditions in which the animals live, sex-specific growth, survival and reproduction through the history of the species.
Székely suggests that one reason for the differences between the sexes is that "female survival increases when males provide some or all of the parental4 care."
He added that "giving birth and caring for young becomes a significant health cost for females and so this cost is reduced if both parents work together to bring up their offspring."
Scientists plan to compare the data on wild mammals with the data on mammals kept in zoos. They want to measure how much biological differences between the sexes affect life expectancy. In zoos, animals do not have to fight with predators5 or fight for food and mates.
Scientists hope the findings will give them a better understanding of what affects length of life in humans. In the past 200 years, the average life expectancy of humans has more than doubled. The main reasons for the increase are improved living conditions and developments in the field of medicine. However, women continue to live longer than men. This suggests biological differences also play a part.
The U.S. Centers for Disease Control says the average American man will live to age 76. The average woman in America will live to age 81. Women can also expect to be healthier than men in their older years. Experts said this is because of a combination of biological and social differences.
A hormone6 in men called testosterone is connected to a decrease in their immune system and risk of heart-related diseases as they age. It is also connected to risky7 behavior, such as smoking, drinking and unhealthy eating habits.
Men are also less likely than women to follow suggestions and warnings from a doctor. And research shows that men are more likely to take life-threatening risks and to die in car accidents or gun fights.


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1 expectancy tlMys     
n.期望,預期,(根據概率統計求得)預期數額
參考例句:
  • Japanese people have a very high life expectancy.日本人的平均壽命非常長。
  • The atomosphere of tense expectancy sobered everyone.這種期望的緊張氣氛使每個人變得嚴肅起來。
2 gender slSyD     
n.(生理上的)性,(名詞、代詞等的)性
參考例句:
  • French differs from English in having gender for all nouns.法語不同于英語,所有的名詞都有性。
  • Women are sometimes denied opportunities solely because of their gender.婦女有時僅僅因為性別而無法獲得種種機會。
3 previously bkzzzC     
adv.以前,先前(地)
參考例句:
  • The bicycle tyre blew out at a previously damaged point.自行車胎在以前損壞過的地方又爆開了。
  • Let me digress for a moment and explain what had happened previously.讓我岔開一會兒,解釋原先發生了什么。
4 parental FL2xv     
adj.父母的;父的;母的
參考例句:
  • He encourages parental involvement in the running of school.他鼓勵學生家長參與學校的管理。
  • Children always revolt against parental disciplines.孩子們總是反抗父母的管束。
5 predators 48b965855934a5395e409c1112d94f63     
n.食肉動物( predator的名詞復數 );奴役他人者(尤指在財務或性關系方面)
參考例句:
  • birds and their earthbound predators 鳥和地面上捕食它們的動物
  • The eyes of predators are highly sensitive to the slightest movement. 捕食性動物的眼睛能感覺到最細小的動靜。 來自《簡明英漢詞典》
6 hormone uyky3     
n.荷爾蒙,激素,內分泌
參考例句:
  • Hormone implants are used as growth boosters.激素植入物被用作生長輔助劑。
  • This hormone interacts closely with other hormones in the body.這種荷爾蒙與體內其他荷爾蒙緊密地相互作用。
7 risky IXVxe     
adj.有風險的,冒險的
參考例句:
  • It may be risky but we will chance it anyhow.這可能有危險,但我們無論如何要冒一冒險。
  • He is well aware how risky this investment is.他心里對這項投資的風險十分清楚。
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