VOA常速英语2008年-Scientists Say Oldest Primate Walked Upright

By Jessica Berman
Washington
21 March 2008

Scientists have concluded that the world's oldest primate¹ fossil known as the Millennium² Ancestor belongs to a group that includes prehistoric³ humans rather than apes. Investigators⁴ studying the remains⁵ have determined⁶ that the six-million-year-old species walked upright, a characteristic that separated human ancestors from apes. VOA's Jessica Berman reports.

Ever since the fossil of the six million year old Millennium Ancestor was discovered in Kenya by French paleoanthropologists in 2000, scientists have debated whether it belonged to the family of prehistoric apes or humans.

An independent team of researchers led by Brian Richmond of George Washington University in Washington, D.C. studied the upper thighbone of the Millennium Ancestor.

Investigators used a statistical⁸ method to compare the fossil to 300 thighbones from great apes and modern humans as well as fossilized human ancient remains.

Richmond says it appears the Millenneum Ancestor walked upright, a characteristic possessed⁹ by prehistoric humans and one that marked the divergence¹⁰ with apes some two million years ago.

Richmond says the evidence can be seen in the hip¹¹ bone of the Millennium Ancestor.

"It doesn't look anything like a modern or a fossil ape," he said. "So we know that this thigh⁷ bone was adapted to upright walking on two legs all the way six million years ago."

But Richmond says the Millennium Ancestor is not a direct ancestor of prehistoric humans.

Rather, Richmond says it appears to be related to a diverse family of human-like primates¹² that arose in Africa much later.

"At six million years ago, the fossil looked so similar to things that are two and three million years ago that it suggests when our early ancestors started walking upright, they evolved a hip anatomy¹³ that remained stable for about four million years for the majority of human evolutionary," he explained. " And there weren't further changes until two million years with the origin of our own genus homo."

Richmond's paper on the Millennium Ancestor is published in the journal Science.

1 primate   

n.灵长类（目）动物，首席主教；adj.首要的

参考例句：

• 14 percent of primate species are highly endangered.14%的灵长类物种处于高度濒危状态。
• The woolly spider monkey is the largest primate in the Americas.绒毛蛛猴是美洲最大的灵长类动物。

2 millennium   

n.一千年，千禧年；太平盛世

参考例句：

• The whole world was counting down to the new millennium.全世界都在倒计时迎接新千年的到来。
• We waited as the clock ticked away the last few seconds of the old millennium.我们静候着时钟滴答走过千年的最后几秒钟。

3 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。

4 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

5 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

6 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

7 thigh   

n.大腿；股骨

参考例句：

• He is suffering from a strained thigh muscle.他的大腿肌肉拉伤了，疼得很。
• The thigh bone is connected to the hip bone.股骨连着髋骨。

8 statistical   

adj.统计的，统计学的

参考例句：

• He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
• They're making detailed statistical analysis.他们正在做具体的统计分析。

9 possessed   

adj.疯狂的；拥有的，占有的

参考例句：

• He flew out of the room like a man possessed.他像着了魔似地猛然冲出房门。
• He behaved like someone possessed.他行为举止像是魔怔了。

10 divergence   

n.分歧，岔开

参考例句：

• There is no sure cure for this transatlantic divergence.没有什么灵丹妙药可以消除大西洋两岸的分歧。
• In short,it was an age full of conflicts and divergence of values.总之，这一时期是矛盾与价值观分歧的时期。

11 hip   

n.臀部，髋；屋脊

参考例句：

• The thigh bone is connected to the hip bone.股骨连着髋骨。
• The new coats blouse gracefully above the hip line.新外套在臀围线上优美地打着褶皱。

12 primates   

primate的复数

参考例句：

• Primates are alert, inquisitive animals. 灵长目动物是机灵、好奇的动物。
• Consciousness or cerebration has been said to have emerged in the evolution of higher primates. 据说意识或思考在较高级灵长类的进化中已出现。

13 anatomy   

n.解剖学，解剖；功能，结构，组织

参考例句：

• He found out a great deal about the anatomy of animals.在动物解剖学方面，他有过许多发现。
• The hurricane's anatomy was powerful and complex.对飓风的剖析是一项庞大而复杂的工作。