So in this case there's across-protection mutualism between these two species in which they help to avoid predation.

“因此在这种情况下这两个物种就形了互惠共生关系。”

Over 90% of the world's plant species form relationships with beneficial fungi.

世界上超过 90% 的植物物种与有益真菌形亲缘关系。

Within the rainforests, diverse plant and animal species created  unique ecological communities.

在雨林中，多种多样的植物和动物物种形了独特的生态群落。

If you gave tiny changes time to a crete, Speciation.

如果你给微小的变化足够的时间去积累，就会生物种形。

And so that's just another idea on how fast speciation can occur.

因此，这仅仅是关于物种形速度的另一种观点。

So we want to turn to talk to speciation.

所以我们想转向讨论物种形。

There hasn't been any, like, new speciation since we started formally distinguishing different bird species.

自我们开始正式区分不同鸟类物种以来，并有生新的物种形。

It drives a lot of that diversity, both in speciation and in morphological diversity.

它推动了物种形和形态多样性方面的大量差异。

Speciation is the process by which new species form, often when populations separate and evolve differently.

物种形是指新物种形的进程，通常生在种群分离并各自独立演化的情况下。

Now if we put that aside, there's been a debate going on over the actual rate of speciation.

现在，让我们暂时放下这个话题，关于物种形的实际速率，学界一直存在争议。

But what we do know about speciation is it starts with reproductive isolation.

但我们所了解的物种形过程始于生殖隔离。

The belief that through time, so if we put t in this direction, speciation occurs gradually over time.

人们普遍认为， 随着时间的推移， 如果我们沿着这个方向放置时间（t），物种形是逐渐生的。

This video is on speciation and extinction.

本视频探讨的是物种形与灭绝。

And kind of the cool thing is that they keep changing, and their rate of speciation is really pretty incredible.

其中相当酷的一点是，它们持续不断地变化，其物种形的速率确实非常惊人。

Plateaus, forests, lakes, coastlines, These various geographical features and climate conditions have helped to form and preserve widely different species.

高原、山林、湖、海岸线，这种地理和气候的跨度有助于物种的形和保存。

And we will talk a little bit more about the mechanisms by which we can speciate.

我们将更详细地探讨导致物种形的机制。

But essentially in speciation you go from one species to two.

但本质上，在物种形过程中，一个物种会分化两个。

Its speakers gradually used the ability to converse with another as two speciating populations begin to lose the ability to mate.

它的使用者逐渐具备了与其他群体交流的能力，就像两个正在形新物种的种群开始失去相互交配的能力一样。

In large genera the species are apt to be closely but unequally allied together, forming little clusters round other species.

在大属中，物种倾向于紧密但不平等地结合在一起， 在其他物种周围形小簇。

This is on reproductive isolation and speciation.

本文探讨的是生殖隔离与物种形。