Scientists wait for Dolly's cause of death

Scientists believe the exact nature of Dolly's death will have a huge impact on efforts to produce cloned humans.

Dolly's death was announced by the Roslin Institute, who decided the sheep should be put down after she developed a progressive lung disease.

" Dolly's health is so crucial and why scientists around the world will be waiting for the results of a post mortem examination on her "
Dr Patrick Dixon
Writer on ethics of human cloning

She became famous for being the first mammal clone when she was born on 5 July 1996.

Dr Patrick Dixon, a writer on the ethics of human cloning, said the nature of Dolly's death would have a huge impact on the possibility of producing a cloned human baby.

'Not old'

"It now seems inevitable that human clones will be born somewhere in the world this year," he said.

"The greatest worry many scientists have is that human clones - even if they don't have monstrous abnormalities in the womb - will need hip replacements in their teenage years and perhaps develop senile dementia by their 20th birthday.

"This is why Dolly's health is so crucial and why scientists around the world will be waiting for the results of a post mortem examination on her."

Professor Richard Gardner, chair of the Royal Society working group on stem cell research and therapeutic cloning, said the results of the post mortem would be essential to assessing any link between Dolly's death and the cloning process.

" We can't rule out that Dolly's death was connected to her status as a clone - but it's important for science now to explore other factors involved "
Baroness Greenfield, Director of the Royal Institution

"If there is a link, it will provide further evidence of the dangers inherent in reproductive cloning and the irresponsibility of anybody who is trying to extend such work to humans," he said.

Speaking to BBC News 24, Professor Ian Wilmut, who led the team who created Dolly, said it was the sheep that was most important.

'Re-wrote biology laws'

"The fact that we were able to produce an animal from the cell of another adult - it had profound effects on biological research and in medicine," he said.

Baroness Greenfield, director of the Royal Institution, warned against "knee-jerk conclusions" to Dolly's death.

"We can't rule out that Dolly's death was connected to her status as a clone - but it's important for science now to explore other factors involved - including the unusual lifestyle enjoyed by the world's most famous sheep," she said.

Dolly was kept inside for much of her early years while she was viewed and examined by various experts.

For some, Dolly's death was confirmation of the flaws in cloning.

LIFE, the national pro-life charity, said it proved that cloning was unnecessary.

Trustee Nuala Scarisbrick said: "I would hope that this wretched thing that has happened would convince the general public that cloning is wrong and should be banned full stop."

Dr Donald Bruce, director of the Church of Scotland's society, religion and technology project, said Dolly "re-wrote the laws of biology".

Commenting on her death, he said: "It is very sad but she did not have a normal life span. Most sheep are killed long before they get to her age.

"It is sad Dolly did not live any longer to see if she could help answer questions about premature ageing."