February 22, 1997: The Roslin Institute, a government research facility in Edinburg, Scotland, announces the successful cloning of a sheep named Dolly, born on July 5, 1996. Dolly was the first mammal to be successfully cloned from an adult somatic cell (one from any part of the body rather than a gamete which is an egg or sperm). They used a process called nuclear transfer. This cloning technique proved that genetic material could be manipulated to express only a “distinct subset of genes” and therefore be programmed to make an entirely new organism.
To get Dolly – whose original cell came from a mammary gland and who was named after Dolly Parton for obvious reasons – was difficult. There were 277 eggs used which resulted in 29 embryos. Of those embryos, only three lambs were born and of those three, only one lived. There have been other farm mammals cloned as well as various other fish, pets, and creatures. Seventy calves have been born after making 9,000 attempts with fully one-third of them dying young. Prometea, a foal, was born after 328 attempts.
Dolly was a Fin Dorset sheep and should have lived 12-15 years. She was euthanized on November 11, 2003 at the age of six. There was debate over her cause of death. Autopsy confirmed that Dolly had a common retrovirus, Ovine Pulmonary Adenocarcinoma (Jaagsiekte), a progressive lung disease. Autopsy also showed that Dolly had unusually short telomeres which normally is the result of aging. Some scientists insist that Dolly’s cellular age at birth was six years as that was the age of the donor sheep and that her telomeres at death were the appropriate size for a 12-year-old sheep.
Cloning raises many ethical questions. The debate increased in 1952 when scientists first announced they had cloned a tadpole. Although the experiment could not be duplicated, ethicists were willing to point out the dangers intrinsic to the procedure. Some religions find the entire process an abomination before God. Others fear that human cloning will be misused or that the clones will be unstable, unhappy, non-distinct creatures used solely as spare parts for the parent.
“The cloning of humans is on most of the lists of things to worry about from Science, along with behavior control, genetic engineering, transplanted heads, computer poetry and the unrestrained growth of plastic flowers.” – Lewis Thomas
“Cloning is the sincerest form of flattery.” – unknown
“The possible cloning of human beings is now not relegated to the world of fiction, and the question to the world is this – what should we do with this science?” – James Greenwood
“Human cloning will take place, and it will take place in my lifetime. And I don’t fear it at all – I welcome it. I think it’s right and proper that we continue this kind of inquiry.” – Tom Harkin