新奇事件簿 人类牙齿的起源（在线收听）

Researchers say they have discovered how humans got teeth. The researchers are from Uppsala University in Sweden.

研究人员称他们已经发现了人类是如何长牙的。这些研究人员来自瑞典乌普萨拉大学。

They say that human teeth "first evolved 400 million years ago". They believe our teeth came from an ancient fish called an acanthothoracid.

他们表示，人类牙齿“首次进化于4亿年前”。他们认为我们的牙齿来自一种被称为acanthothoracid的古老鱼类。

The researchers studied a fossil of the fish. It was difficult to study because the fish is encased in rock.

研究人员研究了这种鱼的化石。由于鱼被包裹在岩石中，所以很难研究。

The researchers had to use the strongest X-ray machine in the world to analyse it.

研究人员不得不利用世界上最强X光机对其进行分析。

They used the X-ray machine to "digitally dissect" the fish.

他们使用X光机对这条鱼进行“数位分析”。

The researchers discovered that the fish's teeth were amazingly similar to human teeth.

研究人员发现这条鱼的牙齿和人类的惊人相似。

The researchers also said humans and 60,000 species of jawed vertebrates living on Earth today come from this fish.

研究人员还表示，人类以及如今生活在地球上的6万种颌类脊椎动物都来自这种鱼。

The researchers say the acanthothoracid was one of the earliest jawed vertebrates with teeth ever to live.

研究人员表示，acanthothoracid是有史以来最早的有牙齿的颚脊椎动物之一。

They were very excited at seeing how similar its teeth were to ours. A co-author of the study, Professor Per Ahlberg, said:

看到它的牙齿和我们的牙齿如此相似，他们非常兴奋。该研究的联合作者Per Ahlberg教授表示：“

"These findings change our whole understanding of the origin of teeth." He commented on the similarity to the fish, saying:

这些发现改变了我们对牙齿起源的全面理解。”他对和鱼的这种相似性进行评论，并表示：

"Their jawbones resemble those of bony fish and seem to be directly ancestral to our own.

“它们的颚骨与多骨鱼的颚骨相似，似乎是我们人类牙齿的祖先。

When you grin at the bathroom mirror in the morning, the teeth that grin back at you can trace their origins right back to the first jawed vertebrates."

当你早上对着浴室的镜子笑时，对着你笑的牙齿，它们的起源可以追溯到最早的有颚的脊椎动物。”

Another researcher said: "Nobody expected to find teeth so deep on the evolutionary tree."

另一名研究人员表示：“没人想到会在进化树这么底层的地方发现牙齿。”