Whatever your view of Dolly the Sheep - the world’s first clone of an adult mammal - it seems hard to deny that scientists had done something that put them close to the miracle of creation.

Ten years on and a string of other animals have been successfully cloned including the first pet cat CopyCat; scientific knowledge has advanced and the cloning technique has been refined, but for the ordinary person on the street there has been little evidence of any miracles in medicine.

In 1997, when Dolly’s birth was announced, it seemed only a matter of time before transgenic animals were being used as a new way to produce human proteins.

Calves Charlie and George - announced to the world in January 1998 - were created from foetal cells in the US to produce the human serum albumin, which is used in blood transfusions, in their milk.

It was promising research then and remains so today, with firms still working towards large-scale use of the technique.

November 1998 saw the suggestion that every child in the country could have their own storage bank of cloned cells just in case they needed a transplant.

Perhaps this sounded too good to be true at the time and the problems in making this dream a reality seem only slightly less complex today than they were then.

The general public could perhaps be forgiven for starting to view what was hailed as the world’s greatest scientific breakthrough of 1997 by the journal Science as nothing more than a historical curiosity. However, the growing band of scientists involved in the field of stem-cell research now look back on the birth of Dolly as a defining moment.

Once it was suspected the process by which an embryonic stem cell branched out, or differentiated, into a specialist cell in the body was irreversible or so complex that it could never be turned back. But the birth of Dolly blew away this idea: the nucleus from the cell of an adult sheep had been placed into an egg stripped of its genetic material and had then gone on to develop into a new living being.

A cell that performed a specific function in the adult sheep’s mammary gland - leading the newborn to be named after country singer Dolly Parton - had been used to create everything inside a new animal: brain, heart, lungs, bones, skin and blood.

While most of the world gasped in horror at the idea of cloning and the prospect that it might one day be carried out on a human, scientists working in the field were inspired by the possibilities: if this could be done, then it meant stem cells could be used to repair organs damaged by injuries or disease.

Some of humankind’s worst afflictions - from motor neurone disease to degenerative brain conditions like Parkinson’s and Alzheimer’s, heart disease, diabetes and spinal cord injuries - might all be treatable in radical new ways with this technique.

Ironically, the sensational publicity that most of them abhorred when Dolly’s birth was revealed in 1997 helped propel Professor Ian Wilmut, the man who led the team responsible for the research, to international fame and that in turn brought recognition of what had been achieved from those responsible for funding science.

Scientists flocked to take part in one of the hottest new areas of science just as increasing numbers of laboratories began carrying out research in the hope of finding a way to harness the seemingly endless potential of stem cells.

Cloning may have grabbed the headlines, but it is not a new revolution in science on the scale of the one eagerly anticipated by those working emerging field of nanotechnology.

Wilmut, who was then at the Roslin Institute but who now works at the University of Edinburgh, says: "I think genetic information in medicine and stem cells, not cloning, are in that category. By comparison, cloning is an also-ran, but it is one that catches the public attention.

"Probably the biggest thing to come from Dolly overall is that people started thinking differently and trying to do things that wouldn’t have occurred to them to do. Dolly showed that the mechanism [of cell differentiation] could be reversed."

Wilmut believes there has been "reasonably good" progress in some areas, while others have been disappointing.

Since Dolly, who died at the age of six, a number of other species have been cloned - cattle, pigs and goats as well as sheep, rabbits, rats, mice, cats, dogs and horses. However, attempts to clone primates have so far failed and those making strident claims about cloning humans range from scientists with maverick reputations to religious cult leaders.

Wilmut says: "People have clearly tried with rhesus monkeys particularly and they have not been successful. There may be something different with the embryos of primates and it will need something new to make it work."

Even in those animals where it has been demonstrated, cloning has remained a tricky task. Dolly was the one successful clone out of 270 embryos that were created by transferring a nucleus into an egg.

The figures are a little uncertain but Wilmut says this "efficiency rate" has probably improved to between 2 and 5 per cent. One of the next breakthroughs Wilmut hopes to see is new technique that brings a step-change in efficiency, something that would, among other things, accelerate the pace of research towards what could be a breathtaking new form of medicine based on stem-cell therapy.

In his new book, After Dolly, Wilmut and science journalist Roger Highfield write: "These primal cells are the stuff of which medical dreams are made. Embryonic stem cells offer the potential for making not only insulin-producing cells to treat diabetes, but also nerve cells to treat degenerative diseases such as Parkinson’s, heart cells called cariomyocytes to treat damaged hearts and other cells to fix liver damage from hepatitis or alcohol abuse.

"They could be turned into twitching heart cells to test new cardiac drugs, or nerve cells to rewire a broken spinal cord - you name it, it could be done."

The trick is to find a way of turning an adult cell from the patient, so it would not be attacked by the body’s immune system, into one with the properties of a stem cell, thus dispensing with the need for immune-suppressing drugs.

Cloning offers a way of doing this: a cell is taken from the patient and its genetic information is implanted into a human egg which then grows into a very early form of an embryo called a blastocyst.

Wilmut is against cloning of humans, but argues that a blastocyst is not actually a person, adding "until a naturally fertilised egg attaches itself to the wall of the uterus, there is no pregnancy" and pointing out that it has "no mental life".

"The critical issue is when this capacity to think first appears," he says in After Dolly. "We are groping for the idea of what some call ‘brain birth’, the mirror image of brain death."

However there are some researchers who are trying to find a direct way of turning an adult cell into a stem cell without the need for cloning.

In what Wilmut describes as "very encouraging and exciting" work, Professor Shinya Yamanaka, of Kyoto University in Japan, recently managed to use a virus to give mouse skin cells some stem-cell-like properties. They were then turned into muscle, nerve, cartilage and fat cells. However, Yamanaka says: "The cells are similar to embryonic stem cells but their differential ability is not sufficient. We expect it would take more than ten years until they would be able to be used for transplants of patients."

In Norway, Professor Philippe Collas, a molecular biochemist at Oslo University in Norway, also managed to give some stem-cell-like properties to an adult cell, by punching holes in the cell wall and then soaking this in a "soup of undifferentiated cells".

This may be a long way from the birth of a cloned sheep, but he is conscious of the "Dolly effect" on his field of science. "Since the announcement of Dolly we have seen a huge amount of labs being set up in many countries. Clearly Dolly’s birth has generated a whole new area of research where people rethink the dogmas," Collas says.

"Knowledge is advanced because what we have seen as a consequence of Dolly is the explosion of nuclear transfer in so many labs. It’s not one lab doing it, you have 50 labs doing it. I think in the next ten years we are going to see the identification of molecules involved in reprogramming cells, so perhaps one day all it will take is to add a handful of molecules and reprogramme them into stem cells.

"The ultimate would be stem cell therapy: being able to take the patient’s own cells and turn them back into the cell the patient needs."

This almost mind-boggling prospect begs the question whether the people of the future will actually die. But Collas says: "If you manage to rejuvenate cells, your whole body would be limited by the other cells. You can put a new part in an engine, but if the car is old, it will still be old." All this talk of potential cures for serious diseases and injuries must be hard to take for those who might benefit from it, but know it is unlikely to happen for ten, 20 or maybe more years. Dougy Johnstone, 38, from Greenock, has no feeling below his navel following a spinal-cord injury sustained in a motorcycle accident in 1999. For the first week after the accident, "I wanted to die," he says.

"I was obviously in a great deal of shock. You don’t really know what’s going on, but once you get your head round it, things change.

"I am completely independent. I don’t rely on anyone for anything and I see myself as the same person, only I use a wheelchair as opposed to walking around."

Johnstone will read newspaper stories about breakthroughs in stem-cell science, but doesn’t seek them out. "In terms of it being a possibility for me, I don’t see it, but there may be other people pinning their hopes on it," he says.

Professor Robin Lovell-Badge, head of developmental genetics at the National Institute for Medical Research in London, agrees that "some of the hype has been ridiculous".

"But for a piece of science that’s had so much hype attached to it, I think it has gone quite well," he says of the progress since Dolly’s birth. "We all want instant cures, but we are not going to get them. I think we are seeing steady progress towards therapeutic applications. They will happen. It is getting closer, but it is still a fair distance off."