It may seem impossible to imagine that a technologically advanced society could choose, in essence, to destroy itself, but that is what we are now in the processnof doing.

If in your lifetime you watch a species go extinct, or plummet almost to the point of extinction, that is a sign that something really serious is going on.

Increasingly developing countries are asking for aid to help deal with the consequences of climate change, which we don't want to give.

Some of these species that are now no longer with us were killed off by a fungal disease that was moved around the planet by people.

Mitochondrial DNA, which is a sort of abridged version of DNA, is passed directly from mother to child, so it's something that can be looked at to trace matrilineal descent.

Several decades ago, a detachment of the American right cut itself loose from reason, and it has been drifting along happily ever since. If the birthers are more evidently kooky than the global-warming "skeptics" or the death-panellers or the supply-siders or the Swift Boat Veterans for Truth, they are, in their fundamental disregard for the facts, actually mainstream.

[On the birther movement:] Here we are, quadrillions of bytes deep into the Information Age. And yet information, it seems, has never mattered less.