Mass extinction is caused by hunting.

大规模灭绝是由狩猎引起的。

The Cretaceous period ended with a mass extinction event.

白垩纪时期以一次大规模灭绝事件结束。

This is the story of wildlife conservation in the age of mass extinction.

这是一个关于大规模灭绝时代野生动物保护的故事。

Are we knowingly causing a mass extinction? Are we evil? No, of course not.

我们是否故意造成大规模灭绝？我们是邪恶的吗？不，当然不。

And it's important to keep in mind that globally, we are living already through mass extinction.

重要的是要记住，在全球范围内，我们已经经历了大规模灭绝。

A new study shows the apparent mass extinction was due instead to a combination of climate change, habitat loss as well as human impact.

一项新的研究表明，动物的大规模灭绝是由气候变化、栖息地的丧失以及人类的影响共同造成的结果。

So this layer clearly represents that something dramatic had happened on earth that caused a mass extinction in a very short time.

所以这一层黏土清晰地表明地球上曾发生过剧烈变化，并在很短时间内导致了大规模灭绝。

Dinosaurs' high level of fitness could also explain why mammals remained so small until the mass extinction of the dinosaurs 65 million years ago.

恐龙的高度适应性可能也解释了为什么哺乳动物的体型总是那么小，这种情况一直持续到六千五百万年前恐龙大规模灭绝。

Only after the mysterious mass extinction of the dinosaurs about 65 million years ago were our ancestors able to emerge into the daylight in any substantial numbers.

只有在6500万年前，恐龙神秘地大规模灭绝后，我们的祖先才有可能大批出现在白天。

Scientists have been searching for the exact cause of this mysterious mass extinction for decades, but most scenarios they've come up with have been, well, less than satisfying.

几十年来，科学家们一直在寻找这场神秘大规模灭绝的确切原因，但他们提出的大多数假设都不尽如人意。