骆驼是一种哺乳动物，但是几维鸟是一种鸟。

The camel is a mammal, but the kiwi is a bird.

youdao

我的意思是，陆行鲸是一种哺乳动物，可以指明一个路上行走动物和水中游泳动物的清晰联系。

I mean, Ambulocetus is a mammal that shows a sort of bridge between walking on land and swimming.

youdao

鲸是一种哺乳动物。

A whale is a kind of mammal.

《新英汉大辞典》

You could do the same thing in mammals and here's one quick example of that, using a different kind of a vector, but inserting a gene into the fertilized egg of a mammal, in this case, a sheep.

你也能在哺乳动物上做到同样的效果,这里有另一个简短的例子,用了另一种载体,把一段基因注入哺乳动物的受精卵中,在这里我们用了绵羊

耶鲁公开课 - 生物医学工程探索课程节选