interview

An Interview with Dr. Colin Stewart

The following is an interview with Dr. Colin Stewart, in which he talks about some future scenario of
cloning.

Question--- Cloning an exact replica of a human being: Could parents use the technology to duplicate a child who is dying of a terminal illness?

Dr. Colin Stewart---"If the child is dying of some congenital or inherited disease such as cystic fibrosis, then the clone of the child would almost certainly die from cystic fibrosis as well. ...You could produce a near exact replica of a healthy child, with all the physical resemblance of the child. There might be some influence on one's physical looks that might come from the mother in the way that the pregnancy proceeded. For example, it's possible that you could be taller or shorter depending on what part of the uterus you're actually attached to. We don't yet know, and I doubt if we ever will know."

Cloning combined with gene alteration: Could someone clone himself and manipulate the genes of the clone to make improvements in himself? How far away is this from producing Einsteins or worker-drones?

"We don't know yet what the genes are that give us our individuality, our characteristics, the genes that are associated with higher intelligence, if there are any. That is simply way in the future. "

Taking nuclei from the dead to create a clone: Could DNA be extracted from the dead to duplicate once living people? Or extinct animals?

"It depends if the dead have been preserved. If they've been frozen or part of their tissues or blood has been frozen, then it might be possible to make a clone. I don't think it would be possible to clone from an extinct animal because the whole nucleus will have disintegrated, losing all structure and causing all the DNA to degrade. Once that happens, you'll never get anything from it. I doubt you would have been able to establish any cells from the Incan Ice Maiden, for example, because ice crystals would almost certainly have formed within her cells and destroyed them. When we freeze tissues for storage, we use a careful freezing procedure and chemicals to keep ice crystals from forming. So it's unlikely that anyone found frozen in the mountains or the Antarctic could be cloned."

Cloning for spare parts: Could people be cloned solely for the purpose of harvesting their organs? Would such clones be an ideal organ source? Could the body parts alone be cloned?

"It would be completely unethical to clone people for the point of taking their organs because they would be individuals; however, there is progress already being made in growing skin in culture dishes at Harvard University, and using that skin to treat people with severe burns. At the moment, we cannot produce spare parts like a kidney, liver or heart in culture; that's why there's so much interest in modifying, say, a pig, to be developed to act as an organ donor for human purposes."

Immortality realized: Could immortality eventually be achieved through cloning? Or a pseudo-immortality in which one person is continually cloned so that genetic make-up is perpetuated for hundreds of years?

"In a sense this already has happened. There have been successful attempts to make clone copies of cattle using very early embryonic nuclei. They have cloned an embryo by transplanting nuclei from an early embryo into another egg. Then they get an embryo from that which acts as the next donor for more transplantation experiments. But they're still not working very well - from all those embryos they were only able to get two cows born. In practice, immortalizing a particular cattle has been attempted and achieved to some extent. So in theory, immortalizing a particular individual would be possible."

Cloning people against their will/without their knowing: Could someone conceivably get enough DNA to clone another person without their even realizing it?

"In theory that would be possible, if you asked someone for a sample of their blood, that would provide all the genetic material necessary to make a copy of that individual. But you would still have to have all the apparatus, machinery and technology to do the experiment itself. It wouldn't be easier in practice to clone someone than, say, a sheep."

The End of Sexual Reproduction: Could cloning replace sex as the means of creating new human life?

"I don't think most people would like to see the end of sexual reproduction. People enjoy it too much! In theory [an all-female population] could be done, but that would almost certainly result in a greater degree of homogeneity in that race of people, making them much more prone to some catastrophe like disease or plague that could wipe them out. The secret to human existence lies in variation and that comes from sexual reproduction."

Color coding:
This is the interviewer.
This is Dr. Colin Stewart.

Interview by TIME.com