title:A Primer on Human CloningHow, Why, and Why Not? (Part 1)
author:Lisa J. Lehr
Medical technology has reached a point where human cloning is beginning to look like a real possibility. But is it really? And if it is, should we do it? Why…or why not?
How is cloning accomplished?
Cloning is a form of asexual reproduction, which does not occur in nature among higher organisms. The method used is called nuclear transfer. It begins with an egg provided by a female donor, unfertilized and with the nucleus removed. The next step is to extract the nucleus containing the DNA, or genetic code, from a somatic (non-reproductive) cell of another donor, and inject it into the “empty” egg. Chemicals are added and the egg is then stimulated by a pulse of electricity, causing the cell to divide and develop into an embryo, which is implanted into a surrogate’s womb.
The offspring of this process would be a clonean exact replicaof the one who donated the DNA (genetically speaking, like identical twins). No genetic material from the other “parent” (or of the surrogate) is present. In theory, it works because all of the genetic information needed to reproduce any organism is present in each of its cells.
All life begins as a single cell. It is still something of a mystery how a higher organism becomes an organized assemblage of bone, skin, nerves, blood, etc. As the cells in an embryo divide (there are many cell divisions in higher organisms) and differentiate, most of the genes in each cell are de-activated, leaving active only the genes that the cell needs to perform its specific role. All of the genetic information remains in that cell, but most of it is chemically disabled. Proteins are selectively synthesized to construct the many different types of tissues.
Dolly the sheep made history as the first successful cloning of an adult mammal. Ian Wilmut, who led the Scottish scientific team that cloned Dolly, has said, “It would be desperately sad if people started using this sort of technology on people.”
Why would we want to clone humans?
Years ago, when we heard the first rumors that human cloning might be on the horizon, it seemed the chief benefit people anticipated was that a clone of oneself would be sort of like a “spare parts” inventory. Say you lose a body part to illness or injury. You take the corresponding part from your clone and have it grafted onto you; no tissue rejection, no need to get used to an artificial organ or limb that is not quite the same as your original oneproblem solved!
The imagined possibilities have since expanded. Now it seems that the main applications for human cloning involve creating not body parts but complete humansreplacing those lost to untimely death, or providing children to infertile couples. A great historical figure could be brought back to do more great work.
The emotional appeal is strong. A parent who has lost a child wants to replace him or her with a duplicate. An infertile couple sees cloning themselves as their only hope. How could we deny those grieving and yearning parents any chance? While on the surface this does not sound as ghoulish as the spare-parts scenario, on closer examination, perhaps it is.
Why would we not want to clone humans?
The first thing to understand about cloning is that a cloned specimen starts life as a baby. You do not get “matching” spare parts; you do not get a family member who picks up right where the departed one left off. Infertile couples would not even get a son or daughter in the strict sense.
The second thing to understand is that the failure rate of cloning is astronomical. The creation of Dolly began with 277 sheep embryos, meaning that 276 died or had to be destroyed.
It gets worse. Most animal clones (to date, sheep, cattle, and mice) die, usually during embryonic development. Others are stillborn with horrendous abnormalities. Mothers have difficult pregnancies and laborious miscarriages; sometimes they die. Both placenta and fetus are abnormally large; some cloned animals will be born twice normal size. Ask any woman if she’d like to carry and deliver, say, a 16-pound baby!
One of the greatest contributions of medical science to length and quality of life is to decrease dramatically the incidence of serious complicationsup to and including deathof pregnancy and childbirth. The foregoing sounds like a giant step backward.
Some babies will die within days or weeks because of abnormalities in vital organs. Survivors remain fragile because of immune system defects. And we don’t know if those survivors’ cells will multiply properly so they don’t get cancer or age too rapidly. Some of these complications may turn out to be fate worse than death. Imagine the strain on our healthcare system!
There is not a single healthy cloned adult mammal alive. Even Dolly grew up extremely obese. It is worth noting that primateshumans’ closest “relative”have not yet been cloned.
It gets worse yet
Beyond the formidable scientific hurdles lies the quicksand of moral ambiguity.
Disposal of less-than-perfect embryos, abortion, and euthanasia may be no-brainer solutions for problems with animal clonesbut for humans, they represent grave ethical concerns.
There is no way to identify defects to ensure that clone embryos implanted in women would be healthy. Proponents say that defective embryos will be screened outbut no such screening process has yet been revealed. If such “quality control” does come about, it raises serious questions of subjective judgment of worth vs. worthlessness. Is this just another incarnation of eugenics? Would cloning technology eventually invade all human reproduction, so that everyone gives birth only to “perfect” children?
Would a human clone be viewed as a creation in the image of Godor as a human invention? What if a cloned individual was made not for “adoption” by a particular couple, but merely as an experiment? Would that child be the “property” of some scientist? Would we eventually see clones being produced with inferior mental functioning to serve as “spare parts” donorspeople who wouldn’t have full awareness of what was being done to them? This begins to sound positively Mengelian. (For those of you who are a little fuzzy on your World War II history, Joseph Mengele was the cretin who did experiments on real live people in concentration camps.)
Moreover, human cloning endangers the stability of the traditional family unit. A “son” conceived by cloning from his “father” would not really be a son but a twin brother. One cell biologist joked, “there’ll be no need for men.” I think that mentality has done enough damage to society without being literally true.
Please continue to Part 2….