首页
登录
职称英语
An Australian research group may ease humanity’s collective conscience over
An Australian research group may ease humanity’s collective conscience over
游客
2024-09-15
12
管理
问题
An Australian research group may ease humanity’s collective conscience over a spate of prehistoric extinctions on the southern continent. The die-off, they say, was not the rapacious work of newly arrived humans, but was due rather to changing climate.
Australia’s large prehistoric animals, called megafauna, were as bizarre as anything that lives there today. King of them all was the marsupial lion, a 130-kilogram meat-eater who lived alongside giant kangaroos, huge lizards called goannas, and Diprotodon, which resembled a three-tonne wombat.
After the arrival of humans on the continent, at least 45, 000 years ago, these weird and wonderful creatures began to die out. Experts blamed the colonizers, arguing that they launched a hunting ’ blitzkrieg’ that wiped out the megafauna(巨型动物)within a few generations.
But the animals may have survived for a lot longer than people thought, argues Judith Field of the University of Sydney, who has analyzed fossil remains. Her excavations seem to show that man and beast lived side by side for as long as 15, 000 years.
She suspects that as Australia approached the most recent ice age, the growing cold and aridity turned much of the continent into a place where these large animals simply could not survive. Although man probably did hunt the large animals, the fact that they survived for so long argues against the blitzkrieg(闪电战)model, she adds.
Field and her colleagues collected animal bones from a ten-metre-deep section of earth at Cuddie Springs, New South Wales. They focused on bones from four layers: two with evidence of human settlement, such as stone tools, and two deeper ones with no evidence of tools.
They dated the bones by measuring the amounts of radioactive elements, such as uranium and thorium, that remained in the bones. They found that the various animal carcasses in each level would indeed have lived cheek by jowl with humans as recently as 30, 000 years ago. The team report their research in Proceedings of the National Academy of Sciences.
Proponents of the blitzkrieg model had previously argued that the dating of the Cuddie Springs material was not certain, but Field says their research clears up the matter. Well-preserved bones at other sites have been very hard to find, probably because they are too dry, whereas Cuddie Springs is the site of an old lake bed.
A second group, reporting in the journal Memoirs of the Queensland Museum, has also unveiled evidence that climate change may have killed off many of Australia’s animals. By looking at smaller animal bones from the Darling Downs in Queensland, they show that their disappearance seems to have coincided with increasing dryness.
But the matter is not settled yet, particularly as the timing of humans’ first foray into Australia has still not been agreed. Fossil evidence from Lake Mungo in New South Wales suggests that they may have arrived 60, 000 years ago. And it is possible that they hastened the megafauna’s demise by burning habitats to make way for primitive agriculture.
Field remains convinced, however, that it was climate that drove the animals to their death. "The arid zone grew to encompass 70% of the continent by 30, 000 years ago, " she says. "There would have been very few opportunities once it got dryer." [br] What do the experts collect to do the experiments at Cuddie Springs?
选项
A、Animal tracks.
B、Animal pictures.
C、Animal bones.
D、Animal fossils.
答案
C
解析
细节题。从第六段首句Field and her colleagues collected animal bones from a ten-metre-deep section of earth at Cuddie Springs,…可知答案为[C]。
转载请注明原文地址:https://tihaiku.com/zcyy/3759289.html
相关试题推荐
[A]excessively[I]degradation[B]collectively[J]neutralize[C]positiv
[A]excessively[I]degradation[B]collectively[J]neutralize[C]positiv
[A]excessively[I]degradation[B]collectively[J]neutralize[C]positiv
[A]excessively[I]degradation[B]collectively[J]neutralize[C]positiv
[A]excessively[I]degradation[B]collectively[J]neutralize[C]positiv
______aresearchstudent,Iwouldatleastmastertwoforeignlanguages.A、Should
ProfessorJohnsonissaid______somesignificantadvanceinhisresearchinthep
ShouldFinancialSupportOnlyBeProvidedforScientificResearch?Thef
AcademicResearchandProjectDesignI.Introduction—【T1】i
AcademicResearchandProjectDesignI.Introduction—【T1】i
随机试题
Manypeoplebelievetheglarefromsnowcausessnowblindness.Yet,withdar
现行的《自动喷水灭火系统施工及验收规范》GB50261-2005要求自动喷水灭火
根据投资者的心理因素,可将证券市场投资者分为()。 ①冲动型 ②冒险型
随着我国科技对经济社会发展贡献率的增大,以及科技介入生活程度的加深,普通人与科技
第一位获得普利兹克建筑奖的中国籍建筑师是( )。A.贝聿铭 B.王澍 C.
始终推动我国先进生产力发展和社会全面进步的根本力量是 A.包括知识分子在内的工
期货现货互转套利策略要精确测算每次交易的所有成本与收益,这个成本的计算受股票现货
李民为一农村青年,2007年大学毕业后工作一直没有着落,就随同乡一起加入了去北
监理规划审核内容中,对安全生产管理监理工作内容的审核包括( )。A.在工程进展中
在建设工程项目进度计划系统中,由业主方、设计方、施工和设备安装方编制的进度计划应
最新回复
(
0
)