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
2023-08-25
20
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 modern 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 modern 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] The ancient man’s closest relatives were _____.
选项
A、the Artic populations
B、the North Americans
C、the northeastern Siberians
D、the ancestors of the Inuit
答案
C
解析
第5段第2句的主句they concluded...表明研究人员在研究这个古人的亲属来源时得出结论:他与西伯利亚东北部的人有亲缘关系,由此可见,本题应选C。
转载请注明原文地址:https://tihaiku.com/zcyy/2955176.html
相关试题推荐
AstudyledbyresearchersattheUniversityofPennsylvaniaindicatesthat
AstudyledbyresearchersattheUniversityofPennsylvaniaindicatesthat
Researchershavefoundthatpeople’smentalabilitiespeakat22beforebegi
Researchershavefoundthatpeople’smentalabilitiespeakat22beforebegi
Researchershavefoundthatpeople’smentalabilitiespeakat22beforebegi
Researchershavefoundthatpeople’smentalabilitiespeakat22beforebegi
Researchershavefoundthatpeople’smentalabilitiespeakat22beforebegi
Researchershavefoundthatpeople’smentalabilitiespeakat22beforebegi
Researchershavefoundthatpeople’smentalabilitiespeakat22beforebegi
Nowmostresearcherswillagreethatvideogamescanhelpaswellasharm.F
随机试题
Whatdidheasktodo?[br][audioFiles]2020m2x/audio_etrktzm_035_202002[/audio
2008年2月19日早6点班,A公司综采一队出勤53人。跟班队长李某和工长苏某对
患者女,27岁。反复发作性肢体抽搐10年。查体:神志清。右侧肢体肌力5级。头颅C
债券价格指数是反映债券市场价格总体走势的指标体系,其作用主要包括()。A.
舒必利属A.丁酰苯类 B.硫杂蒽类 C.苯甲酰胺类 D.非典型抗精神病药
电流互感器二次开路时,其主要现象和后果是:表计为零或指示错误,保护拒动,开路点产
如果贷款合同允许本金负摊还条款,则贷款人会()。A:要求较高的初始贷款利率 B
一方当事人(受托方)为另一方当事人(委托方)就特定技术项目提供可行性论证时订立的
某县应急管理部门针对烟花爆竹生产安全进行专项检查,发现某烟花爆竹生产厂存在重大事
汇总原始凭证与累计原始凭证的主要区别是()。A、登记的经济业务内容不同 B、填
最新回复
(
0
)