Charlotte Uhlenbroek

I'm Charlotte Ullenbrook, a zoologist, and you're listening to Sheba, just like us, from the documentary on the BBC World Service.

Sheba is a chimpanzee.

She was born in a cage, raised in a zoo, and then spent 24 years in a laboratory.

As I learnt more about her story, I kept hearing the phrase, we have the need, but do we have the right?

Having studied chimps in the wild for years, I've always found it hard to accept experimentation on animals, especially ones that are so like us.

The justifications and counter-arguments have raged for decades, and although attitudes have changed, the debate is still unresolved.

In the next hour, I explore our conflicted relationship with the animals we use and the struggle to set them free.

But first, let's meet Sheba.

Hi, Sheba.

How you doing, girly?

What you got around your neck?

Sheba is 44 years old.

Primate researcher and activist Bob Ingersoll knew her for the first 25 years of her life.

But this is their first reunion since 2006, when she finally left a research laboratory and came here to Sanctuary at Chimp Haven in Louisiana.

It's a moment of unmistakable joy.

She's 44.

Listening to Bob talk about Sheba and the memories it brings back of her mother Lily and her father Nim, it's almost impossible to imagine the dark history they all share.

It started with a dream.

Chimps and other primates are so close to us genetically, so sophisticated in their behaviour.

Surely, under the right conditions, we could learn more about ourselves.