Commercial animal cloning is banned in the UK, so Gemini Genetics in Shropshire freezes cells bound for the US

At first glance, Gem is simply a very happy spaniel. With a plush toy in her mouth, she is the embodiment of joy. But her straightforward demeanour belies the complexities of her origins. Because Gem is not your typical dog: she is a clone.

Ever since Dolly the sheep – the first mammal to be cloned using an adult cell – was revealed to the world in 1996, debate has raged over the potential for the technology and its ethical implications.