气候波动影响人类进化史
文章来源:未知 文章作者:enread 发布时间:2011-09-22 06:02 字体: [ ]  进入论坛
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Research at the University of Liverpool has found that periods of rapid fluctuation1 in temperature coincided with the emergence2 of the first distant relatives of human beings and the appearance and spread of stone tools. Dr Matt Grove3 from the School of Archaeology4, Classics and Egyptology reconstructed likely responses of human ancestors to the climate of the past five million years using genetic5 modelling techniques. When results were mapped against the timeline of human evolution, Dr Grove found that key events coincided with periods of high variability in recorded temperatures.
 
Dr Grove said: "The study confirmed that a major human adaptive radiation -- a pattern whereby the number of coexisting species increases rapidly before crashing again to near previous levels -- coincided with an extended period of climatic fluctuation. Following the onset6 of high climatic variability around 2.7 million years ago a number of new species appear in the fossil record, with most disappearing by 1.5 million years ago. The first stone tools appear at around 2.6 million years ago, and doubtless assisted some of these species in responding to the rapidly changing climatic conditions.
 
"By 1.5 million years ago we are left with a single human ancestor -- Homo erectus. The key to the survival of Homo erectus appears to be its behavioural flexibility7 -- it is the most geographically8 widespread species of the period, and endures for over one and a half million years. Whilst other species may have specialized9 in environments that subsequently disappeared -- causing their extinction10 -- Homo erectus appears to have been a generalist, able to deal with many climatic and environmental contingencies11(意外事件) ."
 
Dr Grove's research is the first to explicitly12 model 'Variability Selection', an evolutionary13 process proposed by Professor Rick Potts in the late 1990s, and supports the pervasive14(普遍的) influence of this process during human evolution. Variability selection suggests that evolution, when faced with rapid climatic fluctuation, should respond to the range of habitats encountered rather than to each individual habitat in turn; the timeline of variability selection established by Dr Grove suggests that Homo erectus could be a product of exactly this process.
 
Linking climatic fluctuation to the evolutionary process has implications for the current global climate change debate. Dr Grove said: "Though often discussed under the banner term of 'global warming', what we see in many areas of the world today is in fact an increased annual range of temperatures and conditions; this means in particular that third world human populations, many living in what are already marginal environments, will face ever more difficult situations. The current pattern of human-induced climate change is unlike anything we have seen before, and is disproportionately affecting areas whose inhabitants do not have the technology required to deal with it."


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1 fluctuation OjaxE     
n.(物价的)波动,涨落;周期性变动;脉动
参考例句:
  • The erratic fluctuation of market prices are in consequence of unstable economy.经济波动致使市场物价忽起忽落。
  • Early and adequate drainage is essential if fluctuation occurs.有波动感时,应及早地充分引流。
2 emergence 5p3xr     
n.浮现,显现,出现,(植物)突出体
参考例句:
  • The last decade saw the emergence of a dynamic economy.最近10年见证了经济增长的姿态。
  • Language emerges and develops with the emergence and development of society.语言是随着社会的产生而产生,随着社会的发展而发展的。
3 grove v5wyy     
n.林子,小树林,园林
参考例句:
  • On top of the hill was a grove of tall trees.山顶上一片高大的树林。
  • The scent of lemons filled the grove.柠檬香味充满了小树林。
4 archaeology 0v2zi     
n.考古学
参考例句:
  • She teaches archaeology at the university.她在大学里教考古学。
  • He displayed interest in archaeology.他对考古学有兴趣。
5 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
6 onset bICxF     
n.进攻,袭击,开始,突然开始
参考例句:
  • The drug must be taken from the onset of the infection.这种药必须在感染的最初期就开始服用。
  • Our troops withstood the onset of the enemy.我们的部队抵挡住了敌人的进攻。
7 flexibility vjPxb     
n.柔韧性,弹性,(光的)折射性,灵活性
参考例句:
  • Her great strength lies in her flexibility.她的优势在于她灵活变通。
  • The flexibility of a man's muscles will lessen as he becomes old.人老了肌肉的柔韧性将降低。
8 geographically mg6xa     
adv.地理学上,在地理上,地理方面
参考例句:
  • Geographically, the UK is on the periphery of Europe. 从地理位置上讲,英国处于欧洲边缘。 来自辞典例句
  • All these events, however geographically remote, urgently affected Western financial centers. 所有这些事件,无论发生在地理上如何遥远的地方,都对西方金融中心产生紧迫的影响。 来自名作英译部分
9 specialized Chuzwe     
adj.专门的,专业化的
参考例句:
  • There are many specialized agencies in the United Nations.联合国有许多专门机构。
  • These tools are very specialized.这些是专用工具。
10 extinction sPwzP     
n.熄灭,消亡,消灭,灭绝,绝种
参考例句:
  • The plant is now in danger of extinction.这种植物现在有绝种的危险。
  • The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。
11 contingencies ae3107a781f5a432c8e43398516126af     
n.偶然发生的事故,意外事故( contingency的名词复数 );以备万一
参考例句:
  • We must consider all possible contingencies. 我们必须考虑一切可能发生的事。
  • We must be prepared for all contingencies. 我们要作好各种准备,以防意外。 来自辞典例句
12 explicitly JtZz2H     
ad.明确地,显然地
参考例句:
  • The plan does not explicitly endorse the private ownership of land. 该计划没有明确地支持土地私有制。
  • SARA amended section 113 to provide explicitly for a right to contribution. 《最高基金修正与再授权法案》修正了第123条,清楚地规定了分配权。 来自英汉非文学 - 环境法 - 环境法
13 evolutionary Ctqz7m     
adj.进化的;演化的,演变的;[生]进化论的
参考例句:
  • Life has its own evolutionary process.生命有其自身的进化过程。
  • These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。
14 pervasive T3zzH     
adj.普遍的;遍布的,(到处)弥漫的;渗透性的
参考例句:
  • It is the most pervasive compound on earth.它是地球上最普遍的化合物。
  • The adverse health effects of car exhaust are pervasive and difficult to measure.汽车尾气对人类健康所构成的有害影响是普遍的,并且难以估算。
TAG标签: species climate human
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