首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Catastrophic volcanic eruptions in Europe may have culled Neanderthals to the point where they couldn’t bounce back, according t
Catastrophic volcanic eruptions in Europe may have culled Neanderthals to the point where they couldn’t bounce back, according t
admin
2012-04-23
48
问题
Catastrophic volcanic eruptions in Europe may have culled Neanderthals to the point where they couldn’t bounce back, according to a controversial new theory. Modern humans, though, squeaked by, thanks to fallback populations in Africa and Asia, researchers say.
About 40,000 years ago in what we now call Italy and the Caucasus Mountains, which straddle Europe and Asia, several volcanoes erupted in quick succession, according to a new study to be published in the October issue of the journal Current Anthropology. It’s likely the eruptions reduced or wiped out local bands of Neanderthals and indirectly affected farther-flung populations, the team concluded after analyzing pollen and ash from the affected area. The researchers examined sediments layer from around 40,000 years ago in Russia’s Mezmaiskaya Cave and found that the more volcanic ash a layer had, the less plant pollen it contained.
"We tested all the layers for this volcanic ash signature. The most volcanic-ash-rich layer"—likely corresponding to the so-called Campanian Ignimbrite eruption, which occurred near Naples—"had no (tree) pollen and very little pollen from other types of plants," said study team member Naomi Cleghorn. "It’s just a sterile layer." The loss of plants would have led to a decline in plant-eating mammals, which in turn would have affected the Neanderthals, who hunted large mammals for food. "This idea of an environmental cause for the Neanderthals’ demise has been out in the literature. What we’re trying to do is point out a specific mechanism," said Cleghorn, an anthropologist at the University of Texas, Arlington.
Other theories propose that modern humans played a vital role in the fall of the Neanderthals, either through competition, warfare, or interbreeding. If the volcanoes theory is correct, the Neanderthals’ end was much more tragic: dying slowly in a cold and desolate landscape bereft of food sources. "It’s hard to say what it would have been like to be the last few groups out there, seeing other groups less and less over the years," Cleghorn said.
The Neanderthals were a hardy species that lived through multiple ice ages and would have been familiar with volcanoes and other natural calamities. But the eruptions 40,000 years ago were unlike anything Neanderthals had faced before, Cleghorn and company say. For one thing, all the volcanoes apparently erupted around the same time. And one of those blasts, the Campanian Ignimbrite, is thought to have been the most powerful eruption in Europe in the last 200,000 years. "It’s much easier to adapt to something that’s happening over a couple of generations," Cleghorn said. "You can move around, you can find other places to live, and your population can rebound. " "This is not that kind of event," she said, "This is unique. "
There may also have been small bands of Homo sapiens living in Europe at the time, Cleghorn said. They too would have been affected by the eruptions. But modern humans likely avoided extinction because they had larger populations in Africa and Asia, she said, while most Neanderthals were in Europe around this time. "With their small population groups, Neanderthals did not really have a great source population," Cleghorn said. "They didn’t really have the numbers and the density" to rebuild their populations after the eruptions.
The researchers acknowledge that there are gaps in the volcanoes theory. For instance, the time line needs to be better defined—did the volcanic eruptions occur in a period of months, years, or decades? "At this point, it’s impossible to pin down a reliable date" for the eruptions, Cleghorn said. "We can’t say that this eruption happened 50 years before the next eruption. We just don’t have that kind of resolution." It’s also unknown exactly how long it took the Neanderthals to die out—or how long after the eruptions modern humans began settling Europe in force, she said.
Anthropologist John Hoffecker, though, suggests that modern humans had already begun crowding out Neanderthals in Europe long before the eruptions in question. Judging from discoveries of modern-human artifacts in former Neanderthal strongholds, Hoffecker said, "Neanderthals were clearly in trouble well before 40,000 years ago, because modern humans were occupying certain places, such as Italy, where Neanderthals had been present. So something clearly had gone wrong there. " Perhaps, he added, the volcanic eruptions just dealt the final blow. "I’m not entirely convinced that’s the case either," said Hoffecker, of the University of Colorado. "But at least that’s a plausible scenario that’s consistent with the chronology. " Study co-author Cleghorn counters that the modern human populations living in Europe 40,000 years ago were small and isolated, and only after the Neanderthals were gone did Homo sapiens populations explode. "If modern humans were making any forays into European Neanderthal territory prior to this, they were doing it only on the very margins," Cleghorn said. "What was keeping them from moving very quickly into the heart of Europe? We think Neanderthals were still holding their own and might have held out for much longer, if it hadn’t been for the devastating impact of these eruptions. "
We can learn from the fifth paragraph all the following EXCEPT______.
选项
A、the Neanderthals had once survived several ice ages and was experienced in coping with volcano eruptions
B、the extinction of Neanderthals resulted from a succession of volcano eruptions
C、the volcano eruption happening 40,000 years ago was the most powerful one in the history
D、neanderthals could not adapt to the sudden change of their surroundings
答案
C
解析
首先,要看清题目,问题是找出不正确的选项。所给的三个选项A、B和D都在第四段中得出均为正确的答案。而选项C偷换了概念,与原文内容不符。
转载请注明原文地址:https://kaotiyun.com/show/bWiO777K
0
专业英语八级
相关试题推荐
LegendsaboutKingArthurhaveexistedsincethe6thcentury.Storiesofthemanandhisdoingshavegrownfarbeyondanythingt
Outinthestreetatlast,themanstoppedrunningandlookedbackatthestepsofthegallery.Thewomanwasnotfollowinghim.
SomehearteningstatisticswerereportedlastyearbytheJournaloftheNationalCancerInstitute:themortalityrateforbreas
ThepoeticstyleWaltWhitmandevisedisnowcalled______.
EconomicconditionshaveimprovedduringthepastdecadeinmanyNorthAmericanandEuropeanCBDs,primarilybecauseofanunpre
A、coexistenceB、environmentalprotectionC、internationalcooperationD、reconciliationB
A、naturalbeautifulhighlandsB、mysteriouslegendsandhiddentreasuresC、space,tranquilityandwelcomesD、old-fashionedhumane
Youknowher—thatniceteenageracrossthestreet?Chloe.Theresheis,sittinginoneofthetwocaptain’sseatsinthemidsect
______wasthefirstimportantAmericannovelist.
我多少次想把这一段经历记录下来,但不是为这段经历感到懊悔,便是为觉察到自己要隐瞒这段经历中的某些事情而感到羞耻,终于搁笔。自己常常是自己的对立面。阳光穿窗而入,斜晖在东墙上涂满灿烂的金黄。停留在山水轴上的蛾于蓦地飞起来,无声地在屋里旋转。太阳即将走完自己的
随机试题
男,46岁,腹痛、腹泻3年,结肠镜检查诊为溃疡性结肠炎,用654-2后腹痛缓解,但腹胀加剧,腹膨隆,无肠形及蠕动波和高调肠鸣音。为解痉止痛,下列药物中慎用
Bass刷牙法和Roll法的主要区别在于
[2005年第150题]下列哪一项不是被动式太阳能采暖系统的特点?
以下关于公务员受处分的法律后果不正确的是()。
动物福利是指尊重动物的权利、保护生态环境,促进人与动物协调发展,动物福利主要包括:生理福利,即无饥渴之忧虑;环境福利,即让动物有适当的居所;卫生福利,即尽量减少动物的伤病;行为福利,即保证动物表达天性的自由;心理福利,即减少动物恐惧和焦虑的心情。根据上述定
所有权内容的核心和拥有所有权的根本标志是
下面有关CMM模型的描述中,不正确的是(1)。CMM模型的第三级为确定级,其主要过程是关于项目和组织的策略。以下选项中属于第三级的关键过程是(2)。
(2011年下半年)在项目管理中经常需要在成本与进度之间做出权衡,尽管聘用高级程序员的花费要比初级程序员高得多,却可以获得更高的生产效率。如果项目经理在编制项目质量计划时,希望确定聘用高级程序员和初级程序员的最佳人数比例,同时还要明确质量标准以及达到标准的
通过运算符重载,可以改变运算符原有的()。
考生文件夹下存在一个数据库文件“samp2.accdb”,里面已经设计好“tTeacherl”和“tTeacher2”两个表对象。试按以下要求完成设计:创建一个查询,查找并显示在职教师的“编号”、“姓名、“年龄”和“性别”四个字段内容,所建查询命名为“
最新回复
(
0
)