If you want grown-ups to recycle, just tell their kids the importance of recycling, and they'll be all over it.

I'll admit that the discovery of evolution is humbling, but it is also empowering. It transforms our relationship to the life around us. Instead of being outsiders watching the natural world go by, we are insiders. We are part of the process; we are the exquisite result of billions of years of natural research and development.

Evolution is one of the most powerful and important ideas ever developed in the history of science. Every question it raises leads to new answers, new discoveries, and new smarter questions. The science of evolution is as expansive as nature itself. It is also the most meaningful creation story that humans have ever found.

Climate change is happening, humans are causing it, and I think this is perhaps the most serious environmental issue facing us.

Bicycling is a big part of the future. It has to be. There's something wrong with a society that drives a car to work out in a gym.

America has had many other discoverers besides Columbus, but he seems to have made more satisfactory arrangements with the historians than any of the others.

There really is no such thing as race.