Your life matters. You can't live through a day without making an impact on the world. And what's most important is to think about the impact of your actions on the world around you.

Our brain is almost the same as the chimps', but we have language, we have electronic communications, we've put people on the moon - we are immensely more intelligent. And yet: how come the being with the most extraordinary intellect ever is destroying its only planet?

One individual cannot possible make a difference, alone. It is individual efforts, collectively, that makes a noticeable difference - all the difference in the world!

It's up to us to save the world for tomorrow: it's up to you and me.

If you educate women, family size tends to go down.

What you do makes a difference, and you have to decide what kind of difference you want to make.

I started as - well, I wanted to be Poet Laureate. And I wanted to be a naturalist. That's how I began. I didn't have any desire to go and be a scientist. Louis Leakey channeled me there. I'm delighted he did. I love science. I love analyzing and making sense of all these observations. So, it was the perfect rounding off of who I was into who I am.