Human clone breakthrough stirs hopes and fears

US scientists have discovered a method that will allow them to successfully clone human embryos. The research could save millions of lives, but what is the moral price?

For thousands of years, it has taken two parents to produce a baby. Reproduction is our driving evolutionary force. It has been central to hundreds of different cultures, surrounded by sacred mysteries and social taboos.

But that picture is beginning to change. According to newly published research, US scientists have pioneered a new technique for cloning human embryos. The seed for a new human life can now be created in a lab, grown from DNA from a person’s skin.

This is a breakthrough development. Scientists have created clone embryos before, but the clones never grew bigger than around a dozen cells. The US team, from the Oregon Health and Science University, managed to grow an embryo to around 150 cells.

In principle, it should be possible to implant a cloned embryo like this into a womb, where it would grow into a fully formed human baby. This has been successfully done with other animals. The first animal clone, Dolly the Sheep, was born as long ago as 1996.

But doing the same with a human baby is another matter. Clone DNA is often damaged or defective. The team who cloned Dolly had 276 failed attempts. With current technology, it would be hugely risky, and probably impossible, to bring a cloned human baby to full term.

So why bother cloning embryos? For their stem cells. Embryos are one of the few viable sources of human stem cells – cells with the incredible power to transform into any kind of tissue in the human body. In an embryo, these cells go on to form limbs and organs. If ‘harvested’ and used for medicine, they may be able to repair damaged brain and nerve cells, to heal paralysis or blindness, to stop Alzheimer’s disease. The potential benefits of stem cell therapy are nearly endless. Tissue from a cloned embryo would be a perfect match for the person from whom the clone DNA was taken. Clone embryos could save a donor’s life.

The embryo, however, would not survive – something that makes this line of research extremely controversial even before you consider the ethical implications of human cloning. Taking stem cells from embryos means destroying something that could, in theory, become a human.

Clone wars

Supporters of this research point out that the embryos they use are only about 150 cells big. They have no thoughts or feelings – not even any nerves or organs. They are nothing like a fully formed person. Surely it is reasonable to sacrifice a tiny cluster of cells for the health, or survival, of a thinking, feeling adult human?

But many people, including many scientists, are unconvinced. Even in the modern world, they argue, some things should remain sacred. Among them: the creation and destruction of human life.

You Decide

  1. Would you destroy an embryo to save someone’s life?
  2. Scientists are sometimes accused of playing god. What does that mean and is it necessarily a bad thing?


  1. Write down an imagined conversation between yourself and a newly created but full-sized clone of you.
  2. Try to write a full philosophical definition of the word ‘person’. Do ‘person’ and ‘human’ mean the same thing?

Some People Say...

“A human clone would be an offence against nature.”

What do you think?

Q & A

So when will we see the first clone armies?
Star Wars might have made that seem like a good idea, but it will never happen. Cloning humans will always be difficult and expensive, and there are enough soldiers already just doing things the old fashioned way.
But couldn’t you clone your best fighter a million times? Then you would be unstoppable!
Even if you did, there is much more to humans than just genes. The same DNA can be expressed in totally different ways in different people. Upbringing, diet, environment – these all matter just as much as what’s in your chromosomes.
So cloning is much less fun than it seems on TV?
Yes, but potentially much more useful. If it helps with Alzheimer’s, for example, it could save half a million lives in the UK alone.

Word Watch

In modern usage, something is taboo when it is forbidden or shocking to society. The word comes from an ancient Polynesian word, tapu, meaning ‘sacred’. In Western society, most remaining taboos centre around nudity and sexual intercourse.
Dolly the Sheep
Dolly was born in Edinburgh in 1996 and died aged just six, of lung cancer, leaving six lambs to carry on her line. Her remains are on show at the National Museum of Scotland.
DNA in cells accumulates mutations as people grow older, damaged by chemicals and sunlight. This can be a good thing – random mutation is how evolution advances – but most mutations are useless or harmful. Using DNA from an old cell to make a clone embryo passes on these unhelpful mutations.
Few viable sources
It is possible to force adult cells to turn back into stem cells. This technique shows promise, and could remove the ethical dilemma entirely, but for the moment remains out of reach.

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