GALAPAGOS, BBC1, 9pm

I’LL admit I’m rarely ablaze with excitement when yet another nature documentary comes plodding along – unless it’s a spectacular Attenborough, of course – but this one has the virtue of a famous name. Every schoolchild knows the Galapagos is where Charles Darwin went, studying its creatures and forming his theory of natural selection.

This new three-part series returns to the famous chain of volcanic islands which are home to a thousand species found nowhere else on Earth. Tonight, the team of scientists and biologists search for the island’s famous pink iguanas.

And they do something the great Darwin was unable to: using submersible craft they dive deep into the Pacific Ocean to find species not yet known to science.

It’s a strange feeling to know that the colossus of Darwin didn’t manage to do it all: there are still creatures and crevices on these mysterious islands which are unknown, and this new series will bring the secrets directly to us.

RICH HOUSE, POOR HOUSE, C5, 9pm

EARLIER this week I made a plea on behalf of the little channels, in this case it was ITV Encore, saying that they still manage to offer good stuff occasionally, and we shouldn’t skim over them in the TV listings, but even as I wrote that I knew I wasn’t including Channel 5. No, I’d usually advocate skipping the fifth channel, home of poverty and pets, and yet here I am, suggesting you give it a shot.

Channel 5 (and Four) have been accused of wallowing in “poverty porn” but this new series has something different.

A rich family, the Caddys from Bristol, swap houses with a poor family, the Williams from Weston-Super-Mare. It means a seven-bedroom mansion is swapped for a council terrace, and a household budget of £1700 is exchanged for one of £110, and we get to observe the resulting culture shock. But there’s no sneering or snobbery.