1997: Dolly the sheep and the big breakthrough – the first successful mammal clone from an ordinary adult cell.
1997 to 2000: Scientists at various institutes cloned various species of animal – as other scientists claimed to be working towards the first human clone.
1998: American Dr Richard Seed said he was ready to begin experiments on cloning a human being within the next three months.
January 2001: Controversial Italian doctor Severino Antinori announced plans to clone human babies for infertile couples at his fertility clinic in Rome.
April 2001: Dr Antinori reportedly said that a woman he was treating was pregnant with a cloned embryo. It was later denied.
July 2002: Authorities in South Korea investigated a company’s claim that it had implanted a cloned human embryo in a South Korean woman.
November 2002: Dr Antinori announced that the first human baby clone would be born in January 2003.
February 2003: Dolly the sheep is put down after a veterinary examination showed she had a progressive lung disease.
July 2003: The first UK research licence of its kind permitting a technique that creates embryonic stem cells from human eggs was granted to the scientists who cloned Dolly the sheep in Edinburgh. This is therapeutic, not reproductive, cloning.
September 2003: Dr Panos Zavos claims to have created the world’s first cloned human embryo. He announced plans to implant the human embryo in a surrogate mother later in the year.
October 2003: scientists in China claimed they had created twins which effectively had two “genetic mothers” and one father, but the experiment did not create any live babies. One expert called the experiment “proof of principle” for human cloning, but others disagreed. The work was not aimed at producing genetic copies of humans.
January 2004: Dr Zavos announces a 35-year-old woman is hoping to give birth to the world’s first cloned baby.