Dolly the Sheep Cloned

Setting the scene

Dolly the sheep was announced to the world on February 22, 1997 (though born July 5, 1996), as the first mammal cloned from an adult somatic cell. Dolly was created at the Roslin Institute in Scotland by Ian Wilmut and Keith Campbell using somatic cell nuclear transfer—taking a mammary gland cell from an adult ewe, inserting its nucleus into an egg with DNA removed, and implanting the embryo into a surrogate.

What happened

Dolly proved that differentiated adult cells could be reprogrammed to create a whole organism, overturning the dogma that cell specialization was irreversible. She was named after Dolly Parton because the cell came from a mammary gland. Dolly lived 6.5 years, gave birth to six lambs naturally, and was euthanized in 2003 after developing lung disease and arthritis.

Why it still matters

Dolly's cloning sparked global debate about the ethics of cloning, genetic engineering, and the possibility of human cloning. It led to bans on human reproductive cloning in many countries but also advanced stem cell research and regenerative medicine. Dolly demonstrated that biology was more plastic than thought and opened the era of modern biotechnology. Her birth on July 5, 1996, was a scientific milestone comparable to the discovery of DNA's structure.

Background

Bioethics debates intensified.