In the 1990s, the concept of a molecular clock was developed.

在 20 世纪 90 年代，分子钟的概念被提出。

Molecular clock analyses suggest they evolved about 780 million years ago.

分子钟分析表明它们大约在 7.8 亿年前进化。

And inside our cells, a kind of molecular clock is ticking too, marking  the inevitable process of cellular ageing.

在我们的细胞内部，一种分子钟也在滴答作响，标志着细胞衰老的不可避免过程。

And they appear to have evolved between 95 million and 1.9 million years  ago, based on molecular clock methods.

根据分子钟方法，它们似乎是在 9500 万到 190 万年前进化而来的。

These genetic changes accumulate at a steady rate through time, so scientists can read them like a molecular clock, and estimate how much time has passed.

这些遗传变化会随着时间的推移以稳定的速度积累，因此科学家可以像分子钟一样读取它们，并估计已经过去了多长时间。

Using this molecular clock idea, blood from humans and gorillas was sampled, and it was found that we shared a common ancestor about 11 million years ago.

利用这种分子钟的思想，对人类和大猩猩的血液进行了取样，发现在约 1100 万年前我们的祖先是一样的。

Studies like this are based on the idea of the molecular clock, which hypothesizes that mutations build up at a certain rate.

像这样的研究是基于分子钟的想法，它假设突变以一定的速度累积。

But paleontologists think that the arrival of plants on land actually happened even earlier, based on dates produced by the method known as the molecular clock.

但古生物学家认为，根据被称为分子钟的方法得出的日期，植物登陆陆地的时间实际上发生得更早。

Molecular clocks estimate that many of our earliest animal ancestors diverged during the Snowball Earth period, and diversified immediately afterwards in the Ediacaran, like the last common ancestor of all vertebrates.

分子钟估计， 我们许多最早的动物祖先在雪球地球时期发生了分化，并在埃迪卡拉纪之后立即发生了分化，就像所有脊椎动物的最后一个共同祖先一样。

According to studies based on that model known as the molecular clock, bats seem to have originated around 65 million years ago, just after the extinction of the non-avian dinosaurs.

根据基于分子钟模型的研究，蝙蝠似乎起源于大约 6500 万年前，就在非鸟类恐龙灭绝之后。