I’ve been following the research related to human cloning now for more than a decade. Is human cloning more possible at this point? How do we even define such cloning? Did you know there are two types? The goal of this post is to educate you and in the process answer such questions.
What’s in this post
What is human cloning | Is human cloning real or legal? | More doable to try now | Embryos from stem cells | Cloning machine? | How cloning might produce someone else | Ethical and social justice issues | References
What is human cloning and why are there two types?
There are two kinds of human cloning: therapeutic and reproductive. The latter is making an actual new person with an identical genome to an existing person. See image above that visually explains the 2 kinds of cloning, adapted from my book on stem cells: Stem Cells: An Insider’s Guide. This post is focused on the reproductive cloning that would make a copy of a human being.
Therapeutic cloning, sometimes called somatic cell nuclear transfer or SCNT, isn’t discussed so much these days. In part that might be because the tech to produce induced pluripotent stem cells or IPS cells can create pluripotent stem cells that are genetically identical to an existing person far easier than SCNT. It’s never been clear if SCNT-derived human ES cell lines are any better than IPS cells. For all these reasons, the name “therapeutic” cloning might be outdated.
We’ll see if the future brings any surprises there.
Keep in mind that unlike most movies and TV shows involving cloning in reality clones would be babies. They would not suddenly appear having the same age as you. In Star Wars clones underwent accelerated aging to get to a more helpful age as soldiers. I suppose something like that is possible in real life too but it would be extremely complicated and risky.
Is human cloning real or legal? Claims, old and new
Cloning a person right now is not real. The technology doesn’t exist, but animal cloning methods could be adapted for people to try. More on this dangerous possibility below.
As to legality, to my knowledge there is no national law in the U.S. that would make it illegal. The same is true in many other countries, but some nations do have a prohibition.
It’s funny in a way because people in the distant past have apparently falsely claimed to have made cloned people and the state of the technology back then made it nearly impossible. However, now as the technology has made human cloning even more possible to try no one recently has claimed to have done it. I’m glad no one seems to be thinking about trying human cloning because I think it’s an awful idea. I suppose it’s also possible that people are pursuing this and just not talking about it, which is a disturbing idea.
More than a decade ago a cult called the Raelians claimed they had made cloned people. Although there wasn’t any evidence to support this claim and it was widely discredited, it made international headlines at the time.
Part of the reason why cloning continues to make it into sci-fi and fantasy works so regularly is that people find it fascinating. Cloning also pops up in art as seen in the work of Daisuke Takakura above.
Why trying to clone people is more doable now, but huge risks
There are some key technological differences now as opposed to in the early 2000’s that make attempts at cloning people potentially more doable. At least it could be tried more easily. I still think that successful cloning of people wouldn’t be likely to succeed and the failures could produce very ill babies or cause miscarriages.
It is in addition possible that clones would age much faster than normal or be predisposed to specific diseases like cancer. The clones’ offspring might also have problems.
Despite the huge risks, cloning is now less of a long shot because of IPS cells and new advances in making germ cells from stem cells. As I said earlier, IPS cells can be made to be a genetic duplicate of a person (see caveat in section below on “somebody else”).
It seems likely in coming years that IPS cells will be used successfully to make human eggs and sperm, which could then be used for IVF, and embryos could then be implanted in a surrogate.
There are still technical hurdles here including the fact that female IPS cells wouldn’t have a Y chromosome needed to make sperm via differentiation in the lab. However, that might be something that could be overcome via chromosome transfer technology. Even without that step, female iPS cells could still be used for cloning another female potentially.
Making embryos from stem cells for reproduction
New research is also suggesting the possibility of making human embryos directly from stem cells like IPS cells. These models of human embryos are sometimes remarkably similar to the real thing. Where do we draw the line?
Still another risk here is that human embryos made from IPS cells, whether directly or indirectly through making sperm/eggs could have profound epigenetic changes that disrupt normal human development. A problem here is that you might not know this catastrophic outcome until you tried.
I predict that human embryos made in a lab from stem cells or even models of human embryos made this way will already exhibit enough red flags like epigenetic changes that no one with common sense will consider implanting them.
Another question I’ve gotten is whether there could be a cloning machine.
There is no such machine now, but if someday people use stem cells for cloning people and those stem cells and the resulting sperm/eggs are grown in an incubator, that would almost be like a Brave New World hatchery machine.
Why cloning could rarely produce someone else in a sense
Another issue with trying to clone someone either the standard SCNT way or via stem cells is that we’ve realized in recent years that everyone is what’s called a microchimera.
This means that not all of our cells are perfectly identical genetically. We get a few mutations here or there over the years. Some of our tissues can exhibit what’s called clonal expansion too where one cell in the skin or blood grows faster than the others. These quicker-growing cells then can be overrepresented as compared to others. Such faster growing cells or clones are more likely to have mutations.
They are also more likely to end up being picked for cloning attempts just because there are more of them. They may in addition be more likely to survive the cloning process. I would expect such cells could predispose any clone to develop cancer in the future.
Ethical and social justice issues with cloning
Of course, there are extremely difficult ethical and social justice issues on this path should anyone ever go down it. I’m not convinced it could ever be done safely and ethically, but people are probably going to try it anyway.
Cloning could become a business that dehumanizes people. The clones could be thought of as less than human. Human cloning in the lab would also open the door to tinkering more with CRISPR to try to produce clones who are “new and improved”.
Combine that kind of ethics situation with the reality that other technology is steaming ahead which could be used for cloning attempts and we could be headed for trouble in coming decades.
The He Jiankui misadventures in making CRISPR’d babies show us that rare scientists are willing to do crazy things. Even if there are only a few such scientists in the world they can cause a disproportionately huge amount of trouble. Human cloning is probably a temptation for some of them.
- NY Times piece on Raelians and cloning
- PubMed title cloning article search results on September 7, 2021.