首页
登录
职称英语
Researchers have reconstructed an ancient human genome(基因组)for the first tim
Researchers have reconstructed an ancient human genome(基因组)for the first tim
游客
2024-04-05
38
管理
问题
Researchers have reconstructed an ancient human genome(基因组)for the first time, thanks to the discovery of a 4000-year-old strand of hair in Greenland permafrost(永冻土). Experts say that similar techniques could be employed in many other ways, such as analyzing the DNA of South American mummies or crime victims.
The sample was taken from one of four strands of hair collected in Greenland by Danish archaeologists in the 1980s. The hairs are the only known human remains from the earliest people to settle in Greenland. A chance conversation alerted University of Copenhagen researcher Eske Willerslev, who was just back from two unsuccessful months in Greenland searching for human remains to test for DNA, to the sample, which had been stored at the National Museum of Denmark for more than 20 years.
Once they had the hairs in their possession, Willerslev and colleagues set about sequencing the sample. The team used dozens of sequencing machines to identify and map DNA fragments in the hair shafts, a process that took nearly 2 months. The data revealed more than 80% of the genome, coverage comparable to what can be done with a modem human genome.
"From the DNA, we can tell a lot about the individual," says Willerslev. "He had brown eyes, brown skin, a tendency to baldness, and dry earwax." The researchers have named him "Inuk," which means "man" or "human" in Greenlandic.
The genome also sheds light on where the man’s relatives came from. When the researchers compared his DNA with that collected from more than 40 Arctic and native North American populations, they concluded that the first people to settle in Greenland were related to groups now living in northeastern Siberia. The analysis also revealed that these first colonists were not the ancestors of the Inuit who live on the island now.
The researchers say that when it comes to ancient DNA, the Greenland sample may amount to low-hanging fruit. The hair had been preserved by cold for thousands of years, ideal conditions for recovering DNA "Working with these young permafrost samples is worlds apart from working with older, non-permafrost samples," says Adrian Briggs, a researcher at the Max Planck Institute. He notes that the Greenland sample contains tens of thousands of times more DNA than typically found in Neandertal and early modem human samples from warmer environments.
Yet the discovery shows that with ever-cheaper genetic sequencing and faster computers, it is possible to recover a full nuclear DNA sequence from an ancient human, even when the genome is broken into tiny fragments. The nicest thing this paper shows is that the application of next-generation sequencing techniques is really going to expand what we can do with ancient DNA. [br] When Eske Willerslev decided to test the strands of hair for DNA, _____.
选项
A、he discovered the hair by chance
B、he failed in all the previous tests
C、the hair was found by him in Greenland permafrost
D、the hair was kept in National Museum of Denmark
答案
D
解析
原文该句提到的sample指的就是“头发”的样本,末尾的定语从句表明该头发样本当时收藏在丹麦国家博物馆中,因此,本题应选D。
转载请注明原文地址:https://tihaiku.com/zcyy/3542127.html
相关试题推荐
[originaltext]AnancientGreekphilosopheroncewrotethatlaughteriswhat
Researchershavereconstructedanancienthumangenome(基因组)forthefirsttim
Researchershavereconstructedanancienthumangenome(基因组)forthefirsttim
Inlastyear’sSciencestudy,researchersatJohnsHopkinsUniversityexami
Inlastyear’sSciencestudy,researchersatJohnsHopkinsUniversityexami
Inlastyear’sSciencestudy,researchersatJohnsHopkinsUniversityexami
Inlastyear’sSciencestudy,researchersatJohnsHopkinsUniversityexami
Inlastyear’sSciencestudy,researchersatJohnsHopkinsUniversityexami
TherearemanytheoriesaboutthebeginningofdramainancientGreece.The
TherearemanytheoriesaboutthebeginningofdramainancientGreece.The
随机试题
Alltheinformationwehavecollectedinrelationtothatease______verylittl
某市政项目的独立土方工程,招标文件中估计工程量为100万m3,甲乙合同中约定;土
A. B. C. D.
青黛可用于治疗慢性粒细胞白血病,其有效成分是A.靛玉红 B.青黛酮 C.靛蓝
具有泻下作用的化学成分是A.蒽醌类化合物 B.三萜皂苷类化合物 C.木脂素类
临床上如何确诊“新型冠状病毒感染的肺炎”?( )A.B超检查 B.CT检查
某项目有四个备选方案。方案效果无法准确预测,只能大致估计为较好、一般好和较差三种
工程质量通常体现在()方面。A.适用性 B.可靠性 C.时效
下列关于联苯双酯滴丸剂的叙述中错误的是A.联苯双酯是主药 B.PEG6000为
下列关于工程勘察设计招标的说法,正确的是()。A.工程勘察、设计投标文件应当包
最新回复
(
0
)