Here we are.
我们找到了。
We are run.
我们在跑。
We're in the mountains.
我们在山上。
And it's not in great abundance, but here is a specimen of cannabis.
山上的大麻数量并不多，但这是一株很好的样本。
This plant has been here for millions of years.
这种植物在这里生活了上百万年了，
But what I don't understand is why would this plant have evolved THC, this psychoactive compound.
但我不懂的是，为什么它会含有四氢大麻酚，这种影响精神的化合物？
What was the reason for the cannabis plant?
是怎么进化得到的呢？
I consider that accumulation of THC gives a lot of privilege to cannabis.
我认为含有四氢大麻酚给大麻带来很多的益处。
For example, this plant very resistant to ultra-violet. Extremely.
例如，这种植物对紫外线的抵抗力异常的强。
So it's a defence against ultra-violet light at this altitude?
所以在这样的海拔高度，四氢大麻酚就像是对抗紫外线的盾牌吗？
Yes.
没错。
Okay.
好的。
Another thing, cause the taste of the leaves.
另一个原因是它的味道，
You can taste if you want.
你可以试一下。
I'll have a little bite here.
我来试一点。
Yes, it's not so good.
味道不太好。
Oh, yeah, that's really bad, isn't it?
噢，还真是，很难吃对吧？
Yes, cattle consider the same.
对，牲畜也这么觉得，
And they don't eat leaves and plant during the vegetation period.
所以在生长期时，它们不会吃这种植物。
So just like any other plant, cannabis evolved defences to enable it to survive.
因此，像其他植物一样，大麻进化出这种防御功能，是为了生存下去。
It just so happens that in the case of cannabis, these defences took the form of the chemical, THC.
只是对大麻而言，这种防御的化合物恰巧是四氢大麻酚而已。
But the reason why THC gets you stoned is due to another, entirely unrelated accident of evolution.
但四氢大麻酚能产生迷幻效果另有原因，与进化的偶然性全然无关。
The origins of our response to cannabis strangely preceded the existence of the plant...
不可思议的是，这种迷幻效果的起源，在大麻出现前就存在...
And can be traced back millions of years to primitive creatures living in the ancient oceans.
它能追溯至百万年前的一种上古海洋生物。
And those creatures still exist today, in the more familiar waters of Portsmouth.
而这种生物至今依然存在，在我们熟悉的朴茨茅斯港就能找到。
What we're looking for are some buoys, or a boat that has been here a while.
我们要找的是在这停留过一段时间的船，或浮标。
And maybe on the underside we'll see hanging off the bottom of the buoy, hundreds of these creatures.
可能在水里，我们能看到上百个这种生物粘在浮标的下面。
