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
2024-10-10
19
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 30-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(dears 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 aten-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/3794710.html
相关试题推荐
Whatdotheresearchersfindaboutmessydesks?[br][originaltext]Managers
Whatdotheresearchersfindaboutmessydesks?[br][originaltext]Managers
Foralongtime,researchershavetriedtonaildownjustwhatshapesus—or
Foralongtime,researchershavetriedtonaildownjustwhatshapesus—or
AnAustralianresearchgroupmayeasehumanity’scollectiveconscienceover
AnAustralianresearchgroupmayeasehumanity’scollectiveconscienceover
AnAustralianresearchgroupmayeasehumanity’scollectiveconscienceover
AnAustralianresearchgroupmayeasehumanity’scollectiveconscienceover
Theresearchrequiresmoremoneythan______.(2007年考试真题)A、havebeenputinB、has
The______ofAIDShasledtoaseriousconcernabouttheresearchseekingacure.
随机试题
Leavingtogocollegewasmyveryfirsttimeawayfromhome,andittookalo
Therewerealreadyfourpeoplesittinginthecar,butwetriedtomakearoomf
______[br][originaltext]SentenceNo.1Accordingtosomeresearch,menvisit
[originaltext]W:Hi,I’mnewhere,andIwaswonderinghowIcouldgetalibrar
站用直流电源系统可研初设审查验收,蓄电池组容量为200Ah及以上时应选用单节电压
2005-24.腹痛肠鸣,呕吐泄泻可见于 A.风淫证候B.寒淫证候C.
期货从业人员违反《期货从业人员执业行为准则(修订)》,情节显著轻微,且没有造成后
应当认定期货经纪合同无效的情形有()。A:一方因重大误解订立合同的 B:
以下无需办理注册登记的是()。 A.出口植物源性食品原料种植基地B.
下列统计指标中,不能用定距尺度计量的是( )。A.国内生产总值 B.人口数
最新回复
(
0
)