VOA科学技术2023--Brazilian Cave Objects Suggest Earlier Arrival of Humans in Americas

Brazilian Cave Objects Suggest Earlier Arrival of Humans in Americas

New research suggests humans lived in South America at the same time as giant sloths¹, big animals that disappeared thousands of years ago. The findings² support evidence that people arrived in the Americas thousands of years earlier than once thought.

Scientists looked at small pendants made of bony material from the sloths. The pendants have round holes in them and look polished. The team of researchers said the pendants show signs that humans made them.

The scientists published their findings in Proceedings³ of the Royal Society B. They reported that the material in which the pendants were found dates from 25,000 to 27,000 years ago.

"We now have good evidence — together with other sites from South and North America — that we have to rethink our ideas about the migration⁴ of humans to the Americas," said Mirian Pacheco. She is a co-writer of the study and an archaeologist at the Federal⁵ University of Sao Carlos in Brazil.

Some earlier theories had suggested the first people arrived in the Americas around 15,000 years ago.

The pendants were found 30 years ago in the Santa Elina rock shelter in central Brazil. The new study is the first to carefully study them. The scientists ruled out the possibility that humans had found and made them thousands of years after the animals died. Instead, they say the pendants were made within days or a few years after the animal died.

"We think they were personal objects, possibly for personal adornment⁶," said Thais Rabito Pansani, a co-writer and paleontologist at the Federal University of Sao Carlos in Brazil.

Once among the largest animals in South America, giant ground sloths were three to four meters long and usually walked on all four legs. They weighed more than 450 kilograms.

Other evidence from Mexico suggests humans may have been present in the Americas around 26,000 years ago. Discoveries from Uruguay suggest humans were living there 30,000 years ago.

The evidence from more than one place means scientists have begun to rethink their ideas about human migration. This includes the idea that the first people in the Americas came over what is known as the Bering Land Bridge around 15,000 years ago.

Briana Pobiner is another co-writer of the study. She is a paleoanthropologist at the Smithsonian Institution's National Museum of Natural History in Washington.

While some early populations may have died out in the Americas, "it's very likely that multiple⁷ waves of people came to [the] Americas," she said.

Words in This Story

pendant –n. an object worn around the neck meant to be attractive; a piece of jewelry⁸

polished –adj. a surface that is rubbed or treated in a way that makes it shiny and smooth

adornment –n. something that is worn to improve a person's appearance

paleoanthropologist –n. a person who studies prehistoric⁹ people

rule out –v. (phrasal) to remove from consideration

1 sloths   

懒散( sloth的名词复数 )； 懒惰； 树獭； （经济）停滞。

参考例句：

• Mummies of pleistocene ground sloths, with original skin, hair, tendons and claws have been found. 还发现了保存原有皮肤，毛发，腱和爪的更新世时期地面树懒的木乃伊。
• He was inspired by fossils of armadillos and sloths. 犰狳和树懒化石让他获得了灵感。

2 findings   

n.发现物( finding的名词复数 )；调查（或研究）的结果；（陪审团的）裁决

参考例句：

• It behoves us to study these findings carefully. 我们理应认真研究这些发现。
• Their findings have been widely disseminated . 他们的研究成果已经广为传播。

3 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

4 migration   

n.迁移，移居，（鸟类等的）迁徙

参考例句：

• Swallows begin their migration south in autumn.燕子在秋季开始向南方迁移。
• He described the vernal migration of birds in detail.他详细地描述了鸟的春季移居。

5 federal   

adj.联盟的；联邦的；(美国)联邦政府的

参考例句：

• Switzerland is a federal republic.瑞士是一个联邦共和国。
• The schools are screaming for federal aid.那些学校强烈要求联邦政府的援助。

6 adornment   

n.装饰；装饰品

参考例句：

• Lucie was busy with the adornment of her room.露西正忙着布置她的房间。
• Cosmetics are used for adornment.化妆品是用来打扮的。

7 multiple   

adj.多个(或多项、多种)的；n.（数）倍数

参考例句：

• The number 8 is a multiple of 4.八是四的倍数。
• The most common multiple births are twins,two babies born at the same time.最常见的多胎是双胞胎，两个婴儿同时出生。

8 jewelry   

n.（jewllery）（总称）珠宝

参考例句：

• The burglars walked off with all my jewelry.夜盗偷走了我的全部珠宝。
• Jewelry and lace are mostly feminine belongings.珠宝和花边多数是女性用品。

9 prehistoric   

adj.（有记载的）历史以前的，史前的，古老的

参考例句：

• They have found prehistoric remains.他们发现了史前遗迹。
• It was rather like an exhibition of prehistoric electronic equipment.这儿倒像是在展览古老的电子设备。