Reproductive Human Cloning is Closer than Ever Before.
It’s a Matter of When — and How.
Chinese scientists recently announced they have successfully cloned monkeys. Monkeys are the most closely related animals to humans ever to have been cloned. They therefore represent yet another step toward human cloning… but are they symbolic, significant, or both?
The Cell paper announcing the cloned monkeys’ birth has reenergized a terrific national and international debate over whether we should clone human beings for reproductive purposes. Most would argue “no,” me definitely included.
However, others think “yes.” Ultimately, they will act on their agenda whether doing so is wise or not.
Since the birth of Dolly the sheep in 1997, scientists, bioethicists, and policy makers have asked: “Should we clone human beings?” Some ask this about “therapeutic” cloning (using the technique for therapeutic or research purposes) and some focus on its possible use for reproduction. Unfortunately in this case, the “should” questions we are asking are probably not relevant. The only question whose answer ultimately matters is: “Will someone try to clone a human being with the intent to make a living, breathing, hopefully healthy baby?”
Even though many (including me) hope cloning won’t be used for reproduction, a variety of sources say someone probably will.
A market for the technique, the desire for notoriety, and simple scientific curiosity to see, “Can I do this?” are all drivers that may ultimately result in a human clone.
The Chinese paper shows we are closer than ever before to using somatic cell nuclear transfer to make human babies whose nuclear DNA is virtually the same as their “parent.” SCNT is the process by which the nuclei from various cells are transferred into donor eggs whose nuclear DNA has been removed. For reasons only partly understood, the environment in the eggs “teaches” the donated nuclei to achieve a state more like that of the nuclei of eggs which can, of course, give rise to fully developed organisms. In some cases, these newly created cells can be implanted in the wombs of females, become embryos and at very rare times, develop into fully grown babies who can come to full adulthood.
SCNT may not be the only way to make a human clone. In 2009, two Chinese groups made mice using induced pluripotent stem cells (“normal” cells engineered to regain their ability to allow descendant cells to become any desired cell type.) IPS cells can be made using a wide variety of donor cell types.
At first, viruses were needed to transfer the genes required to induce pluripotency, Boston Children’s Hospital reports there are techniques now available that do not need viral assistance to add the DNA sequences required to get cells to develop pluripotency. This makes the cells easier to work with and may also facilitate their use in attempts at human cloning because the viral DNA doesn’t have to be dealt with.
Unfortunately, there is a market for reproductive human cloning. Given our growing knowledge and skill, it’s only a matter of time before someone figures out how to make a human baby via cloning.
Creating a baby using either IPS cells or SCNT won’t be easy. Making a viable human clone will require making many embryos, most of which will not come to term. Early stories suggest women may volunteer to carry cloned babies to term for reasons like personal desire to prove human cloning is possible. If attempts are made, we may well not find out if the embryos don’t come to term because the scientists won’t want to admit they tried, and failed, to do something so controversial. Alternatively, as happened in 2002–03, claims may be made but independent experts will not receive data needed to prove success or failure.
We will know about a successful procedure if even one baby is born because once provably done, marketing it will make secrecy impossible to maintain. We will ask: “Why did you do this?” The team in question will have answers they think justify making babies whose nuclear DNA is a very close copy of someone else’s. Ultimately, those answers will come down to: “Someone paid us.”
Being paid to make a new vaccine or drug is one thing. Being paid to clone animals so agriculture or science can be more productive or effective, is arguably similar. Being paid to make a baby whose DNA complement is the same as someone already living or recently dead, is at least as ethically complex as it is technically difficult.
Whether clones are made using SCNT or IPS cells, sooner or later, it seems very likely that we will be faced with the fact that techniques being used to increase agricultural productivity and scientists’ ability to do some kinds of animal and disease research have been turned to a more controversial purpose.
When someone has enough “credible” evidence to let them tell a wealthy couple or person: “This technique has a ‘reasonable’ chance of giving you a healthy baby whose DNA sequence is very similar to your designated donor’s,” they may well get the financing needed for a credible attempt at human cloning that will not attend to the legal, moral, and ethical issues trying the procedure carries with it.
Just because the DNA is similar does not mean the clone will develop along the same paths the donor did. Environmental factors like activities, technology and healthcare that impacted the donor’s life will be different than those that shape the clone’s path as Barbara Streisand’s cloned dogs tell us already.
Identical twins have 99+ percent similar nuclear DNA sequences (some mutations arise due to random strikes from ultraviolet light and a few are introduced by the mechanism that lets cells copy their DNA as they divide) and a very similar mix of genes in the randomly assorted mitochondria they got from the single fertilized egg they arose from. Mitochondrial DNA directs many of the activities of the numerous powerhouses our cells depend on for energy and other products. Mitochondrial DNA comes from our mothers’ eggs so identical twins share this inheritance whereas clones do not. Identical twins also grow at the same time and in the same womb. They also live in similar environmental circumstances (similar technology, events, climate, healthcare, culture, familial relationships and resources etc.) after they are born.
Along with the high statistical likelihood most won’t come to term which appears to have numerous underlying causes, clones receive different mitochondrial DNA, grow in different wombs, and live in different times and environments than their donors did.
As I showed in my Genetics dissertation published from Yale in 2004, different countries regulate “controversial” science like cloning in widely varying ways. I focused on the US and UK, but history proves knowledge and skills created in one place can be used in ways some are uncomfortable with in others. In this case, it’s worth noting as of late 2016 reproductive cloning was only banned in forty-six of the UN’s 193 member states.
As our knowledge of cloning science grows, becomes more global, and is increasingly easy to acquire for people with different morals, needs and wants, it seems likely we will need to be ready to answer questions centering on, “How will we manage this?” rather than, “Should we do it?” Actively planning for cloned babies may be our best hope of ensuring the innocents created via human cloning are born healthy, happy, and able to thrive.
