A finger bone is pointing to what scientists are calling a new understanding of how ancient human beings came out of Africa and began settling the rest of the world.
The middle bone of an adult's middle finger were unearthed in the Nefud Desert of Saudi Arabia. It was found in an area called Al Wusta. Testing has dated the fossilized remains to about 90,000 years ago.
Researchers reported that it is the oldest Homo sapiens fossil ever found outside of Africa and the eastern Mediterranean Levant area. They also said it is the first human fossil from the Arabian peninsula.
While the Nefud Desert is now a sea of sand, it was green when this Homo sapiens lived. The researchers say the area was once a grasslands, filled with wildlife, near a freshwater lake.
Our human ancestors first appeared in Africa about 300,000 years ago. Scientists once thought Homo sapiens left Africa in a single, fast migration some 60,000 years ago. It was thought they moved along coastal areas, eating fish and other sea creatures, said Michael Petraglia. He is an anthropologist with the Max Planck Institute for the Science of Human History in Germany.
This fossil bone, measuring 3.2 centimeters from end to end, sug
gests our species left Africa much earlier.
Petraglia explained that the fossil supports the idea that Homo sapiens did not move all at one time, but slowly and over many years. The discovery also shows these people were moving across the interior of the land, not just along the coastline, he added.
Near the fossil finger, scientists also discovered many animal fossils, University of Oxford archeologist Huw Groucutt said. Bite marks on fossilized bones showed that meat-eaters lived in the area.
Stone tools that hunter-gatherers used also were found.
The big question now is what became of the ancestors of the population to which the Al Wusta human belonged, Groucutt said.
We know that shortly after they lived, the rains failed and the area dried up. Did this population die out? Did it survive further south in Arabia? Groucutt asked. He noted that the drying environment may have pushed them into Eurasia.
A report on the findings was published in the magazine Nature Ecology and Evolution.
I'm Susan Shand.
1.belong to 属于
They belong to the Knights of Columbus.
2.dry up 干涸
Reservoirs are drying up and farmers have begun to leave their land in search of water.
3.become of 发生……
What is to become of me if you go away?
4.date to 源于
It clearly shows clerics holding up the shroud and is dated to around 100 years before Leonardo was born.
5.The researchers say the area was once a grasslands, filled with wildlife, near a freshwater lake.
be filled with 充满
Maria and I want your life to be filled with both.
They are like an empty canvas, waiting to be filled with knowledge andexperiences.
6.A finger bone is pointing to what scientists are calling a new understanding of how ancient human beings came out of Africa and began settling the rest of the world.
point to 指向，表明
All the evidence points to his guilt.
He pointed to the house on the corner and said, “That’s where I live.”
沙特阿拉伯内夫得沙漠发现了某成年人的中指指骨，发现于中部省(Al Wusta) 。测试显示，这份指骨化石大概是9万年留下的 。
根据研究人员的报告，这是在非洲以外以及地中海黎凡特地区最古老的智人化石 。研究人员还表示，这也是阿拉伯半岛第一次发现人类化石 。
虽然如今的内夫得沙漠是一片沙地，但智人生活的时期，这里曾是一片绿色 。研究人员表示，该地区曾是一片草原，到处都是野生动物，附近还有淡水湖 。
人类祖先首次出现在非洲大陆上大概是在30万年以前 。曾几何时，科学家还以为智人在大约6万年前在一次快速的迁徙中离开了非洲 。迈克尔(Michael Petraglia)表示，科学家还曾以为，智人是顺着沿海地区迁徙的，这样途中便可以以鱼类等海洋动物为食 。迈克尔是一位人类学家，就职于德国的普朗克研究所，主要研究人类历史学 。
迈克尔解释道，这份化石支持了这样的观点，即智人并没有一次性地进行迁徙，而是用时多年慢慢地迁徙 。这次发现还表明，智人是通过内陆迁徙的，而非沿着海岸线迁徙，迈克尔如是说道 。
在这份化石附近，科学家还发现了许多动物化石，哈佛大学考古学家休(Huw Groucutt)如是说道 。骨头形成的化石上有咬痕，这表明该地区曾有食肉动物生活 。
他们在这里生活不久后就停止了降雨，整个地区遭遇了干旱 。这些智人祖先灭绝了吗？又或者他们在阿拉伯半岛南一点的地方存活了下来呢？休有这样的疑问 。休还表示，由于这里环境干旱，所以他们可能被迫迁徙到了欧亚大陆 。
苏珊 尚德(Susan Shand)为您播报 。