Dinosaurs have been extinct for millions of years.

恐龙已经灭绝几百年了。

But that's what researchers have been deducing from a 70-million-year-old fossil clam.

但研究人员正是从7000年前的蛤蜊化石中推断出了史。

In geologic time, a million years is recent history.

在地质学角度看来，一百年前属于史。

Modern humans arose in Africa about 200,000 years ago.

现人类大约在20年前出现在非。

And so some time around 200,000 years ago, our species confronted this crisis.

大约在20年前，我们人类面临着这场危机。

They then spread across Europe and Asia sometime after 60,000 years ago.

然后在6年前的某个时候，他们传遍了欧亚。

Most species just last for a few million years.

大多数的动物 仅仅存在不到一百年。

As for whether modern-day humans need to worry about this 405,000-year oscillation?

“那现人类是否需要担心这种以40.5年为周期的振荡？”

The last polarity reversal took place some 770,000 years ago.

最一次地磁极性倒转发生在大约77年前。

The fossil record shows that many species have endured for millions of years— so why shouldn't we?

化石资料表明很多物种曾生存百年之久，凭什么认为人类不能？

You can't be too careful these days.

还是小心驶得年船啊。

About 10,000 years ago, this crater was created by nature itself.

大约一年前，这个火山口自然形成。

Here it is better to say " better safe than sorry" .

在这里，说" 小心驶得年船" 会更好些。

After millions of years, in 2019, the great whites of Cape Town have vanished.

在这里生存了数百年后，在2019年，开普敦海域的大白鲨消失不见了。

OK, so we'll start by going back thousands of years.

好的，那就让我们回到千年之前吧。

For most people over millions of years, that doesn't happen.

对于数百年来的大多数人来说，这种情况不会发生。

Millions of years of evolution later, you can see the difference.

数百年的进化之后你可以看出差异 。

Tens of millions of years later, we see another bird-like dinosaur enter the stage.

几千年后我们看到了另一种似鸟的恐龙进入这个发展时期。

About a quarter of a million years ago, humans began to hunt zebras and antelope.

在大概25年前，人类开始捕猎斑马羚羊。

Earth would never be the same - at least not for millions of years.

地球将永远不会以前一样——至少在几百年内不会。