Even Stone Age humans enjoyed the finer things in life, such as animal-tooth jewellery. Capitalizing on ancient fashions, scientists have extracted DNA from a 20,000-year-old deer-tooth pendant to identify the person who presumably either made or wore the ornament — a woman of north Eurasian ancestry ¹ .

To do so, the team developed an elaborate process to extract DNA from the tooth without damaging the priceless specimen. The pendant was unearthed in Denisova Cave in Siberia, Russia, which was occupied by various species of hominin over 300,000 years . The study was published in Nature today.

“It’s almost like you open a time travel machine,” says study co-author Elena Essel, a molecular biologist who works on ancient DNA at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “With each sample we are able to learn a bit more and make more inferences about how these people lived.”

Unidentified objects

An animal’s genetic material is stored deep within the pores of its bones and teeth. Artefacts that were extensively touched, such as a necklace pendant, can also carry the DNA of the person who handled them in the deep past. Previously, it was impossible to associate tools and jewellery with those who handled them unless the artefact was found near a specific burial.

Essel and her colleagues coaxed DNA from inside the pores of the ancient pendant by soaking it in increasingly warm salt solution, which they found did not alter the pendant. Once released, the small amounts of genetic material were sequenced and compared with other sets of ancient DNA.

Mitochondrial DNA — which is handed down from mother to offspring — extracted from the pendant show that the object is roughly 19,000 to 25,000 years old and that the tooth belonged to a wapiti, also known as an elk ( Cervus canadensis ). Analysis of nuclear DNA from the ornament suggests that it had been made or worn by a female Homo sapiens whose genetic make-up resembles that of north Eurasian individuals who lived around the same time but were previously known only from remains found farther east in Siberia.

Study co-author Elena Zavala, a geneticist now at the University of California, Berkeley, says that the technique can connect ancient humans to “the tools that they created” — but, unlike other methods, does not destroy the artefact.

However, there are a number of drawbacks to the method. Modern DNA can easily contaminate an artefact, making analysis difficult. And even for the cleanest specimens, the DNA-extraction method is time-consuming, requires sophisticated technology and must be performed in a specialized laboratory. Essel and her colleagues are working to streamline their process. In the meantime, archaeologists can minimize contamination by wearing gloves and a face mask, and by immediately popping specimens into a refrigerator.

Still, Ludovic Orlando, a molecular archaeologist at the University Paul Sabatier in Toulouse, France, who was not involved in the study, was impressed by the thoughtfulness and efficiency of the team’s procedure. The technique is not “a magic bullet”, says Orlando. But it still provides “a signature from nothing, from a piece of bone or tooth”, he adds. “You see the population signature of the people who interacted with the animal.”

Essel finds it comforting that humans living so long ago took the time and effort to make jewellery to adorn themselves. “It’s so special for humankind that despite all odds, you have the hardest life on Earth, but you still try to seek the beauty in life.”

article_text: Even Stone Age humans enjoyed the finer things in life, such as animal-tooth jewellery. Capitalizing on ancient fashions, scientists have extracted DNA from a 20,000-year-old deer-tooth pendant to identify the person who presumably either made or wore the ornament — a woman of north Eurasian ancestry1. To do so, the team developed an elaborate process to extract DNA from the tooth without damaging the priceless specimen. The pendant was unearthed in Denisova Cave in Siberia, Russia, which was occupied by various species of hominin over 300,000 years. The study was published in Nature today. “It’s almost like you open a time travel machine,” says study co-author Elena Essel, a molecular biologist who works on ancient DNA at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “With each sample we are able to learn a bit more and make more inferences about how these people lived.” An animal’s genetic material is stored deep within the pores of its bones and teeth. Artefacts that were extensively touched, such as a necklace pendant, can also carry the DNA of the person who handled them in the deep past. Previously, it was impossible to associate tools and jewellery with those who handled them unless the artefact was found near a specific burial. Essel and her colleagues coaxed DNA from inside the pores of the ancient pendant by soaking it in increasingly warm salt solution, which they found did not alter the pendant. Once released, the small amounts of genetic material were sequenced and compared with other sets of ancient DNA. Mitochondrial DNA — which is handed down from mother to offspring — extracted from the pendant show that the object is roughly 19,000 to 25,000 years old and that the tooth belonged to a wapiti, also known as an elk (Cervus canadensis). Analysis of nuclear DNA from the ornament suggests that it had been made or worn by a female Homo sapiens whose genetic make-up resembles that of north Eurasian individuals who lived around the same time but were previously known only from remains found farther east in Siberia. Study co-author Elena Zavala, a geneticist now at the University of California, Berkeley, says that the technique can connect ancient humans to “the tools that they created” — but, unlike other methods, does not destroy the artefact. However, there are a number of drawbacks to the method. Modern DNA can easily contaminate an artefact, making analysis difficult. And even for the cleanest specimens, the DNA-extraction method is time-consuming, requires sophisticated technology and must be performed in a specialized laboratory. Essel and her colleagues are working to streamline their process. In the meantime, archaeologists can minimize contamination by wearing gloves and a face mask, and by immediately popping specimens into a refrigerator. Still, Ludovic Orlando, a molecular archaeologist at the University Paul Sabatier in Toulouse, France, who was not involved in the study, was impressed by the thoughtfulness and efficiency of the team’s procedure. The technique is not “a magic bullet”, says Orlando. But it still provides “a signature from nothing, from a piece of bone or tooth”, he adds. “You see the population signature of the people who interacted with the animal.” Essel finds it comforting that humans living so long ago took the time and effort to make jewellery to adorn themselves. “It’s so special for humankind that despite all odds, you have the hardest life on Earth, but you still try to seek the beauty in life.” vocabulary:

{'Capitalizing': '动词，大写，指将字母变成大写，以强调或突出某些文字','Hominin': '名词，古人类，指古代人类的祖先，包括现代人类和其他灭绝的人类物种','Elaborate': '形容词，复杂的，指详细考虑，精心制作的','Unearth': '动词，发掘，指从地下挖掘出来','Presumably': '副词，大概，指推测，猜测','Coax': '动词，哄骗，指用温和的方式说服或劝说','Sequenced': '动词，排序，指按照一定的顺序排列','Mitochondrial': '形容词，线粒体的，指细胞中的一种细胞器，可以产生能量','Handed': '动词，传递，指从一个人传递给另一个人','Offspring': '名词，后代，指父母的子女','Extensively': '副词，广泛地，指大量地，广泛地','Contaminate': '动词，污染，指使某物受到有害物质的影响','Streamline': '动词，简化，指使某事物变得更加简单，更有效率','Drawbacks': '名词，缺点，指某事物的缺点，不利之处','Thoughtfulness': '名词，体贴，指考虑周到，体贴的行为','Efficiency': '名词，效率，指工作或活动的有效性','Magic bullet': '名词，神奇的解决方案，指一种可以解决所有问题的方法','Signature': '名词，签名，指某人的特征，标志','Interacted': '动词，交互，指两个或多个人之间的交流','Adorn': '动词，装饰，指用装饰物装饰某物，使其变得更加美观'} readguide:

{'reading_guide': '本文讲述了科学家从一枚20,000年前的鹿牙项链中提取DNA，以确定制作或佩戴这件饰品的人的身份，他们发现这位女性来自北欧亚的血统。科学家们开发了一个复杂的过程来提取牙齿中的DNA，而不会损坏宝贵的样本。文章还提到，这种技术可以将古代人类与他们创造的工具联系起来，但也存在一些缺点，比如现代DNA很容易污染，而且提取DNA的过程非常耗时，需要先进的技术和专门的实验室。文章最后指出，尽管生活艰难，但人类仍然试图寻找生活中的美好。'} long_sentences:

{'sentence 1': 'Artefacts that were extensively touched, such as a necklace pendant, can also carry the DNA of the person who handled them in the deep past.', 'sentence 2': 'Mitochondrial DNA — which is handed down from mother to offspring — extracted from the pendant show that the object is roughly 19,000 to 25,000 years old and that the tooth belonged to a wapiti, also known as an elk (Cervus canadensis).'}

Sentence 1: 句子结构：主语+谓语+定语从句+宾语+宾语从句 语义分析：本句描述了古代的人类制作的饰品，如项链坠，可以携带处理过它们的人的DNA。

Sentence 2: 句子结构：主语+谓语+定语从句+宾语+宾语从句+定语从句 语义分析：本句描述了从项链坠中提取的线粒体DNA显示，这个物体大约是19000到25000年前的，而且牙齿属于麋鹿（Cervus canadensis）。