A British man who has reached 65 can expect to live another 17.6 years - women get a further 20.2 years.
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It is the ultimate battle of the sexes - and women usually win. Now scientists have come up with a new theory for why woman live, on average, longer than men: men are more biologically ‘disposable’. The controversial theory, developed by Professor Tom Kirkwood of the University of Newcastle, suggests that the female body is better at carrying out routine maintenance and keeping the body’s cells alive. Professor Kirkwood believes there is now growing evidence to suggest that men are more disposable than women, because the cells of their bodies are not genetically programmed to last as long as they are in females. Many scientists believe that the aging process is caused by tiny faults throughout our body. As the tiny faults build up the length of our lives is determined by how quickly our body is able to carry out running repairs. As the cells miss opportunities to repair themselves our body gradually degrades until we eventually die. Professor Kirkwood’s theory behind why our cells do not mend every tiny problem in our body is that it is built into our DNA. The reason we do not live forever is because it would have cost our hunter-gather ancestors too much energy to constantly replenish cells when hunger was a more immediate danger, he says. ‘Under the pressure of natural selection to make the best use of scarce energy supplies, our species gave higher priority to growing and reproducing than to living forever,’ he writes in the magazine American Scientist. 'In humans, as in most animal species, the state of the female body is very important for the success of reproduction', he writes. ‘The foetus needs to grow inside the mother’s womb, and the infant needs to suckle at her breast. So if the female animal’s body is too much weakened by damage, there is a real threat to her chances of making healthy offspring. The man’s reproductive role, on the other hand, is less directly dependent on his continued good health.’ (Read by Renee Haines. Renee Haines is a journalist at the China Daily Web site.) (Agencies) |
這是兩性之間的終極較量——而且通常女性獲勝。 如今,關(guān)于女性為何通常比男性長壽,科學(xué)家們提出了一種新的說法:從生理上來講,男性的身體更“不耐用”。 這一頗具爭議的理論是由紐卡斯?fàn)柎髮W(xué)的湯姆?柯克伍德教授提出來的。他認(rèn)為,女性的身體更易于進(jìn)行日常保養(yǎng),使身體細(xì)胞存活。 柯克伍德教授認(rèn)為,現(xiàn)在有越來越多的證據(jù)表明,同女性相比,男性的身體更不耐用,其原因是男性的身體細(xì)胞基因構(gòu)造不像女性的一樣能維持那么久。 許多科學(xué)家認(rèn)為,人體衰老的過程是由全身的各種微小毛病引起的。因為這些微小毛病不斷累積,人類生命的長短也將取決于身體進(jìn)行自我修復(fù)的速度有多快。 由于各種細(xì)胞錯過自我修復(fù)的機(jī)會,我們的身體狀況也會逐步惡化,直到最終死亡。 至于我們的細(xì)胞為何不能修復(fù)身體中的各種微小毛病,柯克伍德教授認(rèn)為,這是由我們DNA的先天構(gòu)造決定的。他說,我們不能長生不老的原因在于,我們的祖先是以打獵和采集為生的,不斷修復(fù)細(xì)胞會使他們耗費太多的能量,而饑餓對他們來說是更直接的威脅。 他在《美國科學(xué)家》雜志上發(fā)表的文章中寫道,“面對自然選擇的壓力,要最大程度地使用稀缺能源,我們的物種更加注重成長和繁殖,而不是長生不老。” 他還寫道,“正如大多數(shù)動物一樣,對人類來說,女性的身體狀況對繁衍的成功與否至關(guān)重要。” “胎兒需要在母親的子宮內(nèi)成長,嬰兒需要吮吸母親的乳汁。因此,如果女性的身體過度受損,那么她生出健康后代的可能性就會受到嚴(yán)重威脅。相對而言,男性在繁衍中的作用,并不是那么直接地依賴于長期擁有健康的身體。” 相關(guān)閱讀 (中國日報網(wǎng)英語點津 實習(xí)生強(qiáng)鳳華 編輯:陳丹妮) |
Vocabulary: disposable: made to be thrown away after use 用后即丟棄的 |