It doesn't have any slashing ability. It's basically a vestigial arm.

它的前肢没有挥砍能力。基本上是退化残留。

Up to 85% of people have a vestigial muscle called the " palmaris longus."

多达85％的人有一种叫“肌”的退化肌肉。

It's vestigial, meaning it no longer serves its original purpose.

它经过退化，这意味着它不再具有最初的功用。

There are several other vestigial structures like the plica semilunaris in the human body.

人体中还有其它的退化结构，例如半月形褶皱。

Unlike other vestigial structures, though, the appendix isn't always harmless — it can become dangerously inflamed.

不过，与其他退化结构不同，阑尾并不总是无害的，它会严重发炎。

I am betrayed by my appendix, a vestigial organ.

我被自己的阑尾所背叛 就一退化的器官。

Most of these became vestigial long before homo sapiens existed, quietly riding along from one of our ancestor species to the next.

其中大多数在智人存在之前就已退化了，从我们的一个祖先进化到另一个祖先的过程中逐渐退化。

Or are they relics of our evolutionary past, having once served some important purpose only to persist into the present as vestigial remnants?

或者它是我们进化过程中的遗留物，曾经服务于一些重要的目的，但现在只是因为存在而存在，就像残留的遗迹一样？

Vestigial traits can persist when there's no incentive to lose them — but since there's also no incentive to keep them, random mutations will sometimes still eliminate them from part of the population.

如果没有诱因去除退化了的性状，它们就会持续存在——但由于也没有动机保留它们，随机突变有时仍会消除部分人的这一性状。

In fact, the vestigial atmosphere is still slowly dissipating into space. Why? Well, researchers believe that solar wind and radiation is behind the theft, and they're planning a mission to find out, called MAVEN: Mars Atmosphere and Volatile Evolution Mission

事实上，残余的大气层仍在缓慢地消散于太空中。为什么呢？唔，研究人员认为太阳风和辐射是" 幕后黑手" ，他们打算开展一项任务来找出原因何在。这项任务名为MAVEN——火星大气与挥发物化任务（Mars Atmosphere and Volatile Evolution Mission）。