Why we find our dead relatives fascinating — but living ones dull

HERE’S a strange thing. Wildlife and science presenter Liz Bonnin was in Martinique in the Caribbean to research her ancestry in Who Do You Think You Are? (BBC1), and she had already suffered a few melodramatic moments.

When she discovered that her much-loved grandmother on her father’s side was descended from white plantation owners on the island, she got anxious.

And when she learned that Granny’s great-grandfather Francois-Alexandre owned a platoon of slaves, including girls as young as 13, she was overcome.

‘Stop filming,’ she ordered through angry tears and, when she failed to compose herself, had to break off and put away the documents. The thought that her forebear, 180 years ago, had bought and used child slave labour sent her into a spin.

The truth is, of course, that-all of us have 32 great-great-greatgrandparents. It would be surprising if at least one of them wasn’t a nasty bit of work.

But all was fine, because it turned out that Francois-Alexandre had married a slave woman — so Liz was descended not only from slavers but from slaves. It got better still when she discovered that Francois-Alexandre’s own mother, Pauline Zoe, had been a slave herself.

This was fascinating and romantic, but it wasn’t the weirdest twist. That came when Liz visited the site of her family’s former plantation, and met other descendants of this unconventional couple. There were quite a lot of them: Francois-Alexandre had been ‘le coq du village’ or the local stud, joked one man.

But the show didn’t stop to ask these cousins’ names, nor what they did for a living, nor how many children they had themselves. Liz didn’t want to know, and neither did the viewer. These were her blood relatives, though to be fair you had to go back nearly two centuries to find the connection.

The odd truth is that we’re not really interested in our obscure living relations. It’s the dead ones we find addictive, and that’s what makes this series so successful. Liz had welled up over every marriage certificate or christening document, but she didn’t get such a lump in her throat when she met some strangers who shared a fragment of her DNA.

In fact, a fragment is sometimes all it takes to create a perfect replica. Two comedy fans, one an Israeli Jew, the other an American, were brought together a couple of nights ago on Channel 4’s Finding My Twin Stranger, and appeared so alike that computer software could barely discern a shade of difference between their faces.

It turned out they were related, by a great-great-great-grandfather in the mid-1800s. Because they looked identical, they struck up an immediate rapport — unlike Liz and her distant cousins, who were completely unalike.

But the way we think about these links across the generations might change. People are living much longer: it’s not unusual now for centenarians to meet their grandchildren’s grandchildren. Perhaps instead of sifting through dusty documents, youngsters will actually see their great-greatgreat grandparents face to face.

Meet Your Ancestors — I’d watch that.

For the capybara at Chester Zoo, there’s no mystery about parentage. As we discovered in The Secret Life Of The Zoo (C4), it’s all down to Jeff. Capybara are rodents. They look like guineapigs crossed with St Bernards, and they breed like mice. It’s not unusual for a female to have more than 100 pups in her lifetime.

That means Jeff, the sole male in the herd, is a busy fellow. But when it comes to childcare, he is nowhere to be found.

It’s the same with monkeys — Eubank the capuchin has five boys and he doesn’t lift a finger to help with any of them.

The footage in this series, from fixed cameras inside the pens and cages, is rarely very clear. Too often the animals are half out of shot or out of focus. But if, like me, you’re happy to watch disjointed pictures of animals doing just about anything, it’s an undemanding way to pass an hour.