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
2023-11-12
33
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/3180146.html
相关试题推荐
Nowherebutinthecontinuousresearchwork______findthemeaningofhislife.
Accordingtotheresearchfindings,wecaninferthat[br][originaltext]US
Accordingtotheresearchfindings,wecaninferthat[originaltext]USdocto
Thosewerethegraduatestudents______todotheresearchworkinthelab.A、to
Nosooner______apaperonhislatestresearchthanhewasaskedtowriteanothe
Researchersdiscoveredthatplantsinfectedwithavirusgiveoffagasthat___
Heisvery______aboutthesuccessofhisresearchinphysics.A、modernB、moderniz
WhatareresearchersinIBMworkingon?[originaltext]Handheldgadgetsstori
AccordingtoresearchersinTaiwan,sealevelswouldbemuchhigherif______.[o
Whyaresomebabymilkcompanyaccused?[br][originaltext]Medicalresearch
随机试题
Itmayturnoutthatthe"digitaldivide"--oneofthemostfashionableof
材料: 观察植物细胞 目的要求: (1)制作植物细胞的临时装片,学习
2011年我国全年货物进出口总额36421亿美元,比上年增长22.5%。其中,
财务报表的作用主要有()。A.财务人员核对账目 B.国家有关部门进行宏观经济调
通信网中的()是通信网通信的汇点和终点,亦称原始消息和发射信号间的交换。A.
下列关于头肩顶形态的说法中,正确的是()。A:一般来说,左肩与右肩高点大致相等,
(2019年真题)某项目环境影响评价需要对环境空气质量进行现状补充监测,下列监测
新生儿败血症最常见的病原菌是( )。A.大肠杆菌 B.绿脓杆菌 C.链球菌
某工程项目施工采用《施工合同条件》,工期为15个月。承包方投标所报工期为13个月
(2011年真题)根据城市、镇规划区的建筑工程,规划许可证包括建设用地规划许可证
最新回复
(
0
)