Question 2. To mate and then produce young animals.

交配，然后后代。

Only those rats given the saline sired offspring.

只有那些注射了理盐水的老鼠能后代。

The hope is that the oysters will help clean the water and also have babies.

人们希望这些牡蛎能够帮助清洁海水并后代。

At that age, they reach sexual maturity, meaning the fish were able to produce young.

它们在这个年龄达到性成熟，这意味着它可以后代。

First, some organisms reproduce asexually, so they don't need other organisms to produce offspring.

首先，有些物是无性的，所以它们不需要其他物后代。

For years, palaeontologists have wondered if the same was true of plesiosaurs.

数年，物学家一直想知道蛇龙是否也通过怀胎方后代。

By 1511, every ship leaving the Americas for Spain was ordered to bring back five breeding pairs.

到1511年，每艘离开美洲前往西班牙的船只都被命令带回五对可以后代的火鸡。

And he'll spend the next three years on the sea before eventually returning to breed as a breeding adult.

他将在海上度过接下的三年，最终以成年海鹦后代的身份返回陆地。

They produced young generally by laying eggs.

它们通常通过产卵后代。

Like all organisms, tomatoes make more offspring than can survive in nature.

和所有物一样，西红柿在自然界中的后代数量超过了它的存能力。

Do they multiply by laying eggs or giving birth to babies?

他们是通过下蛋，还是产仔后代的呢？

The Penguins migrate to the frozen sea ice every year to breed and raise their young.

企鹅每年都会迁移到结冰的海冰上和养育后代。

This is why creatures make so much effort to produce offspring that are as different as possible.

这也就是物努力后代如此不同的原因。

When an animal leaves more offspring, its genes will spread.

当动物出更多后代时， 就意味着它们的基因得到传播。

Their reproductive offspring inherit the throne, meaning that their colony may persist for decades to come.

他们的后代继承了王位，这意味着他们的民地可能会持续数十年。

So we're talking about core tenants of Darwin's theory and more offspring are always produced for a species than can survive.

所以我们在谈论达尔文理论的核心宗旨以及的后代总是比能够存下的后代多。

When it comes to reproduction, they do the real work, so they get to decide which traits survive and which ones just die out.

就后代而言，她们在做实际的工作，所以她们能决定哪些特质可以保留，哪些可以消失。

Even though members of this colony have the exact same DNA, the ants that reproduce live for about a year.

尽管这个蚁群的成员拥有完全相同的 DNA，但后代的蚂蚁能活大约一年。

At best, their dietary rigidity could limit their ability to reproduce or to care for their young.

即便作最乐观的估计，它们这种僵化的食谱也会限制它们的能力或扶养后代的能力。

If you put in a lot of parental care, then you don't have the resources to make lots and lots of babies.

如果在抚养方面投入太多，那用大量后代的精力就会不足。