Like a family tree, with the most primitive ancestral forms at the trunk, evolving into more derived species on the branches.

就像一棵家谱，在树干上有最原始的祖先形态，在树枝上演化出更多的派生物种。

If you look at what a modern ear of maize looks like compared to its ancestral form, you'll see something very different.

如果你看看现代玉米穗与其祖先形式相比的样子，你会发现一些非常不同的东西。