Dolly the Sheep The first ever clone of an adult mammal

Ian Wilmut, an embryologist, was a leading researcher at the Roslin institute in Scotland when he began to experiment in the world of cloning. He began research in 1986, and on July 5, 1996, Dolly the sheep was born, becoming the first ever cloned adult mammal. Dolly eventually died in February of 2003 at 6 years old, which is quite young for a sheep.

How was Dolly Cloned?

Dolly was cloned by a process called somatic cell nuclear transfer (SCNT) which involves taking a mammary cell from one sheep and combining it with an egg cell of another sheep. The mammary cell donates its nucleus into the egg cell and because of this the DNA of the clone will match that of the mammary cell donor. This egg cell is then placed in the uterus of a third sheep and a fetus forms.

Why was Dolly cloned?

There are many benefits to being able to clone large mammals:

  • They can be cloned with genetic diseases and be used to find cures.
  • We can use this technology to save endangered species.
  • Variables while testing on clones are little to none, since all clones from the same cell line are genetically the same.


Successfully cloning an adult mammal didn't only create applications in the science community. It also created ripples in animal rights groups. Many people believe that cloning animals is unethical and that using them purely for science violates their rights. People were also afraid of what they believe would come next: human cloning.


Because of Dolly's premature death many people believe that cloning creates animals who have shorter life spans; however, Dolly's death had nothing to do with her older cells. Dolly's death has been attributed to a lung disease that she acquired in her lifetime. Dolly did however have arthritis most likely due to her starting with older cells and thus shorter telomeres. There hasn't been enough testing to conclude cloning creates unhealthier animals.

More Clones

Dolly wasn't the only cloned sheep at Roslin institute. After Dolly's successful cloning, four more sheep were cloned with the same cell line and are currently as healthy as any normally born sheep. These four sheep are already 9 years old, and show no signs of premature aging yet. Plenty of clones have shown signs of shorter than normal telomeres; however, there has been more cases of clones with completely normal telomere lengths than clones with short telomeres. The shorter the telomeres are, the older the cell is.

Dolly's place in history

Dolly has a very important place in history, because she is the beginning of a new chapter in science and health. Scientists have a long way to go before finding out if cloning is viable, but without a doubt it will lead to great scientific discoveries for the preservation of man and nature.

Works Cited

"Dolly the Sheep." Video Collection, 14 Oct. 2013. Biography in Context, Accessed 2 May 2017.

Feltman, Rachel. "Dolly the sheep died young - but her clones seem perfectly healthy as they turn 9." Washington Post, 26 July 2016. Biography in Context, Accessed 2 May 2017.

"Ian Wilmut." Newsmakers, Gale, 1997. Biography in Context, Accessed 2 May 2017.

"Recognise us? Four secret healthy clones of Dolly the sheep." Daily Mail [London, England], 27 July 2016, p. 27. Biography in Context, Accessed 2 May 2017.

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