Clearly we could devastate the world... as far as we know, the Earth is the only place in the universe where there is life. Its continued survival now rests in our hands

Crying wolf is a real danger.

I suspect that happiness is not a state but rather a transition.

All our environmental problems become easier to solve with fewer people and harder - and ultimately impossible to solve - with ever more people.

Life is not all high emotion. Some of the most interesting things are when its not highly emotional: little details of relationships and body language.

Opponents say natural selection is not a theory supported by observation or experiment; that it is not based on fact; and that it cannot be proved. Well, no, you cannot prove the theory to people who won't believe in it any more than you can prove that the Battle of Hastings took place in 1066. However, we know the battle happened then, just as we know the course of evolution on earth unambiguously shows that Darwin was right.

I'm luckier than my grandfather, who didn't move more than five miles from the village in which he was born.