1. Human cloning / 2. Genetics & free will / 3. Human gene patents / 4. Human races /

5, 6. Human gene editing


Scroll down to a  numbered question  and click on it to find its answer.




1. Will human cloning become routine one day? If something can be done, isn’t it inevitable that it will be done, eventually?Answer:  Not necessarily. Where there’s a will, there’s often a way; but just because there’s a way doesn’t mean there’s always a will to do it.    There’s little incentive for cloning whole human beings (unlike, for example, the incentive for in vitro fertilization, where there’s clearly a market for the procedure).

   What might theoretically be accomplished by human cloning?

   (A) Making an army of robots that would unquestioningly obey orders, or a football team with players all of whom are equally talented? The present system works fairly well without cloning technology. Besides, in any organization there are advantages to having different personalities and talents: leaders and followers at different levels, technicians and on-the-ground soldiers, pilots and navigators, quarterbacks and fullbacks and wide receivers and placekickers.

   (B) Having a genetically identical clone available for safe tissue- or organ-transplants? There are easier ways to accomplish this, without cloning a whole human being. We are not far from being able to use our own adult stem cells as a source for almost any tissue desired, and methods for transplanting whole complex organs such as kidneys from imperfectly matched donors are improving all the time. And there are moral objections to making a whole human being just for the purpose of having a source of parts.

   (C) Replacing a child lost to disease or accident, with another child exactly the same? This is not a good idea, for two reasons. (1) A child made by taking a cells from a dying child and using cloning technology to make another genetically identical child would not really give the same child back again. The lost child cannot be replaced with an identical one. What makes a person is not genes alone; look at the differences between identical twins (a “natural clone”), who are never exactly alike in temperament and personality. (2) Every person deserves a life for the sake of herself or himself, not just as a replacement for someone else.

   Another argument against deliberate human cloning is that, for the foreseeable future, cloning technology will be fraught with failures, with many defective embryos being produced and having to be discarded in the process. (Of the 21 successful pregnancies in the experiments that produced Dolly the sheep, only 8 live lambs were born.)





2. If genes determine who we are, is there room for free will?  –  Answer: The answer depends on what you mean by “determine” and by “free will.” There are deep divisions among thinkers on this subject.

   “Genetic determinism” proposes that our genes completely determine who we are and what we do. Nobody believes that, even though genes do have an influence on our temperament, our personality, and our decisions. For example, “identical twins” are in fact not identical in personality, behavior, thought processes, and preferences, so genes can’t be completely determining those things. Other factors have equally strong effects: details of family circumstances, degree of wealth or poverty, education, interactions with parents, peers, friends and enemies, individual experiences of diseases and accidents, and so on. If these other factors completely determine who we are and what we do, that is “environmental determinism,” and nobody believes in that either.

   If genetic and environmental factors together completely determine our thoughts and behavior, that is “strict determinism” pure and simple. Here is the debate: when you take into account all genetic influences and all environmental influences (from the womb up to the present moment), is there anything more? Some say no (there is no such thing as free will, which is an illusion), others say yes (free will does exist; we use it every day in all kinds of decisions).

   From studies of similarities and differences between twins, and between children adopted into the same or different families, it has been estimated that maybe at least 90% of the differences between people (their mental processes, emotions, and personality traits) can be explained by genetic differences combined with differences in childhood environments and experiences. That doesn’t leave much room for free will in those areas. There remains the possibility of free will in the decisions of day-to-day life. In the greater maturity of adulthood, however, it is a common experience to look back at one’s childhood, adolescence, and early adult life, and see how many of what looked like free choices at the time were in fact determined by unconscious psychological factors, the social environment, and one’s pre-determined personality.

   Recent neurobiological research suggests that many of our supposedly conscious choices are in fact prepared in advance of our being conscious of them. Brain mechanisms are operating unconsciously to evaluate the situation before acting. (Those brain mechanisms are set up by genes in the human embryo that forge the human brain in the first place.)

   If free will consists of an ability to make choices independent of one’s basic nature and independent of prior experience and current circumstances, then we are probably don’t really have free will in the usual sense. We are just subtle and complicated machines. In the last analysis, the idea of “free will” may be an illusion, an illusion that is itself one of the brain’s functions. If free will is an illusion, it is a pleasant one, and an indispensible device for greasing the wheels of our lives and our social interactions.

   But if one relaxes the definition of “free will” a bit, and defines it as a natural brain process unconstrained by any simple set of genetic or environmental factors, a process that allows us to evaluate both internal and external conditions, to make unconscious calculations, and to act accordingly, then to that extent we have free will. This is enough for daily living.




3. Should human genes be able to be patented?  –  Answer: There are reasonable arguments both for and against the patenting of human genes.

   The basic idea behind granting patent rights is to permit inventors to reap the rewards of the invention for a time (usually 20 years), allowing them to recoup their expenses, continue their work, and keep on contributing to society.

   Patents are given both for invented methods and for invented products. The invention must be genuinely new, not just a slight or obvious modification of something already in existence; and it must be immediately practical and useful, not just something that theoretically might be useful some day.

   Naturally occurring organisms and normal products of nature – such as a newly discovered species of plant or animal, or the sap from a maple tree – cannot be patented. But organisms that have been made by cross-breeding or genetic engineering – such as a hybrid rose or orchid, a genetically modified bacterium that digests oil spills, or a specific mixture of natural products that in just the right proportions gives medical benefits – can be patented.

   It has been argued that isolated human genes should not be patented because (1) they are normal products of nature; (2) there is nothing new or inventive, these days, in the methods used in isolating a gene; (3) their use in genetic testing is an obvious extension of normal practice in medical genetics, so that there is nothing “genuinely new” about them; and (4) granting a patent for a gene subverts the idea of patenting as a means for helping society advance, because the required payment of royalties and licensing fees stifles further research on the gene by other scientists.

   The arguments that human genes should be patentable are the following. (1) The gene as isolated does not occur in nature: it is separated from the DNA sequences adjacent to it in human cells, and it often has some DNA sequences removed from it and/or added to it, making it even more different from its natural state; (2) it often has attached to it artificially synthesized DNA segments that make it easier to copy in a test tube and to transfer into another cell, so it is “a new composition of matter,” and therefore patentable; (3) the isolated gene often requires special DNA modifications and special methods before it can be used in genetic testing or in gene therapy, and in those cases is not “an obvious extension of pre-existing methods and compounds”; and (4) royalties and licensing fees paid by users to the “inventor” of an isolated gene can be used to help advance the inventor’s further research on the gene, and after a patent is granted, public disclosure (required by law) allows other researchers to find new uses for the gene; besides, the patent can include a provision that exempts research uses (as opposed to commercial uses) from licensing and royalty requirements.

   All these points have been disputed in courts, depending on the details of a given patent application.

   Some people worry about the following slippery slope: first, we allow individual genes to be patented; then combinations of genes; then whole new cells; then combinations of cells; then whole new organisms; and eventually we will allow people to be patented.

   Genetically modified cells and organisms – either by selective breeding, or by modern methods of genetic engineering – have in fact been afforded patent protection for decades. They are “new compositions of matter” and “human inventions resulting from human ingenuity and research.” However, at least in the U.S., people cannot be patented. In 2011 the “Leahy-Smith America Invents Act” was made federal law. It says, “Notwithstanding any other provision of law, no patent may issue on a claim directed to or encompassing a human organism” – including human embryos and human fetuses.




4. Are human races just socially constructed? – Answer: “No” and “Yes.”

   The “NO” answer: Human races are genetically real, not just socially constructed. Virtually every species that is widespread is composed of populations that differ genetically, to a greater or lesser degree, from one geographic location to another. This is as true of humans as it is of countless numbers of plant and animal species that have been surveyed. The genetic differences are almost always a reflection of evolutionary adaptation to environmental differences from place to place. In the human species, some people have a lactose-tolerance gene where cows were domesticated thousands of years ago (northern and central Europe); some people have genes for dealing with polyunsaturated fats where historically there have been diets high in marine mammals and fish (Greenland and the coast of West Africa); some people have genes allowing them to live where oxygen levels are low (Tibet, the high Andes,); some people have genes that lighten the skin after their prehistoric ancestors migrated northward out of Africa tens of thousands of years ago and needed more sunlight for their skin cells to synthesize adequate amounts of vitamin D (Europe and Asia). Other examples can be found in the article by S. Fan, M.E. Hansen, Y. Lo, & S.A. Tishkoff, “Going global by adapting local: a review of recent human adaptation.” Science, vol. 354, pp. 54-59 (Oct 7, 2016) ( However, there is no correlation between such “adaptive genes” in a population and other genes affecting other traits, such as personality type and intelligence. Such genetic differences as there are between populations are real, but the boundaries between them are never sharp, and they have become even more blurred with modern travel, intermarriage, and wars of conquest.

   Although the concept of “race” is only loosely defined genetically, biologists still find it useful in describing differences among populations of plants and animals. Different human populations differ in the same general way, but biologists tend to refrain from using the word “races” for them because the term plays into people’s prejudices.

   The “YES” answer: Human beings tend to construct social meanings around group differences. Such social constructs have little or nothing to do with biological differences that may or may not exist between the groups. Here are a few examples. In 1813 Christoph Meiners wrote that there are two main races of human beings: “beautiful” (intelligent, virtuous, and white-skinned), and “ugly” (intellectually inferior, full of vices, and dark-skinned). (Guess which race Meiners himself happened to belong to.) In recent times, British police classified people into 6 races: White, Mediterranean, African, Indian/Pakistani, Asian, and Arab. In Brazil the basic categories of people are White, Black, Yellow, Brown, and Native. The most recent U.S. Census has more than 20 categories, including White, Black, Amerindian, Korean, Eskimo, Pacific Islander, Vietnamese, Chicano, Cuban, and others. These classification schemes are obviously constructed primarily for social purposes. Note also that “racial” conflicts occur between people that by any objective measure would be considered members of the same race: Palestinians vs. Israelis, English vs. Irish, Pakistanis vs. Indians, Shia vs. Sunni in the Middle East, Hutu vs. Tutsi in Rwanda, North vs. South in the American Civil War, etc., etc. It seems that basic human nature includes loyalty to one’s own group, along with antipathy toward and mistrust of other groups, whose members are excluded by virtue of their religion, language, politics, cultural practices, skin color – whatever differences are most obvious. This tendency is in perpetual tension with the other innate human traits of cooperation, altruism, and recognition of a common humanity.










5. Should humans have their genes edited?  Answer: CRISPR technology (see “Genetic Technology” page, Question #2), has made gene editing—changing the DNA sequence of one or more genes—easier than ever before. But should it be done, especially on ourselves?

   In many cases that are being contemplated and in a few cases are even in the early stages of being implemented, the goal is to cure a genetic disease—sickle-cell anemia, muscular dystrophy, hemophilia, Huntington disease, congenital deafness, immunodeficiencies, cardiovascular disease, and other genetic diseases, even cancer. In such cases the goal is to remove a defective gene or replace it with a good copy of the gene in the affected cells. Except for some technical problems that may have to be solved (e.g., sometimes some other genes besides the defective one are also altered), there is little dispute about such applications of gene-editing technology (usually aimed at single genes)—as long as they’re safe and effective, and are intended to treat genetic defects and relieve suffering (1 and 2 below). However, ethical issues arise in two other areas of possible application: (3) enhancing human capabilities; that is, genetically changing people so that they are superior in some way to the average person; and (4) changing the genes of early embryos so that the edited genes would be present in all the cells of the eventual adults, including “germ cells” (eggs and sperm) that will form the next generation.

   Opinions on the issues of genetic enhancement and germline (inherited) gene-editing vary, and are often opposed. Don’t expect to find definitive answers here, but here are some of the main issues (along with some comments):

   (1) Research practices: Sources of human cells and human embryos and permission to use them for research purposes can be a concern. It is generally agreed that if the cells of an identifiable person are to be used for research, that person should give his/her permission. But as far as the use human embryos in research is concerned, our society is in some conflict. Federal guidelines forbid the funding of federal research in which human embryos are created or destroyed purely for research purposes, but they do not expressly forbid the research itself if privately funded. The question remains: should human embryos, even at their earliest stages, be used for research at all?

   (2) Clinical applications: Within the medical framework of gene therapy in general, there is agreement that the use of gene-editing technology should be regulated by review boards and government agencies (e.g., the FDA; other countries have similar oversight institutions).

   (3) “Enhancement” or improvement: The aim here is not to merely correct defective genes, but to alter genes in order to get a “better” human being, maybe someone beyond the normal range of variation. It has been suggested that gene editing for enhancement be limited to producing gene variants that already exist in natural human populations. Here are some questions that have not been definitively answered:

       (a) What would constitute an “improvement beyond the normal human range,” and under what social circumstances would the change be considered an “improvement”? Would it include a cosmetic change in the shape of a child’s nose? A change in the color of one’s skin? A genetic change making a person less likely to become an alcoholic? Alterations in one’s immune system giving greater resistance to sexually transmitted diseases? Gene changes that would make someone able to see in the ultraviolet range, like goldfish and doves and honeybees? A change in genes boosting one’s IQ to a very high level, even if that would entail not fitting in to one’s family or society any more? The environment in which a gene change is effected makes a difference. (Some of these gene edits are currently impractical and might not have the intended effect, because (i) they might require changing many genes at the same time, perhaps at the embryonic or fetal stages of development, (ii) they might have unanticipated consequences, and (iii) the desired trait might be only partially determined by genes in the first place. For example, we know of at least 40 genes that influence IQ; some of them act only in the very early stages of brain development. They are not really “IQ genes”; they just happen to have an indirect influence on IQ scores. Most of these genes have basic cellular functions in many parts of the body (including brain development and brain activity), and altering them could have untoward health consequences. Attempts to alter them would be ill-advised, unless we are sure of all the roles that such genes have in all the various organs and tissues of the body. And, depending on the circumstances, variation in IQ scores may be determined at least as much by early childhood experience as by genes, so gene editing in this case may have only minor effects on IQ.

       (b) Would gene-editing technology be available only to those who could afford it? This might create a “genetic elite,” a class of people who would be genetically superior to everyone else in society. How could the technology be distributed equitably, so that everyone across the world would have equal access to it? Given human behavior so far, it seem unlikely that this could ever be achieved.

   (4) Germ-line modification: This is not just somatic-cell modification (i.e., body cells only), but involves changing genes that can be passed on to future generations. The same ethical considerations as with somatic-cell gene editing for therapy and for enhancement apply here also, but there are some additional considerations. 

      (a) Gene editing that alters embryos is bound to result in some abnormal embryos and fetuses (and even newborns). What level of this kind of failure is society willing to tolerate, if any? One in a hundred? One in a thousand? Even with newborns that appear healthy at birth, should there be long-term monitoring of all such babies and children for the rest of their lives?

      (b) Gene editing that modifies genes to be passed on to descendants may relieve future generations from certain inherited diseases but, especially in the case of non-disease-related gene modification, is necessarily done without the consent of anyone in those future generations.

      (c) Edited genes passed on to future generations may have unpredictable and uncontrollable effects on the long-range future of our species. Should we be taking such risks when Nature—that is, evolution—has produced humans that by and large are well adapted to the Earth environment? If we apply gene-editing technology on a wide scale, could we be disturbing the natural order of things, which is the result of millions of years of evolutionary fine-tuning? This concern is sometimes expressed in this form: “Should we be playing God with our genes?”

   The following guiding principles could be used in discussions of these issues—

  • Everyone in society should have some say in how gene editing is employed; at the outset, no one should be excluded from the discussions. (This will of course demand that everyone should make an effort to educate themselves about gene editing’s benefits and risks. And, as with all major technological innovations, future generations will necessarily be excluded from these discussions!)

  • Whatever benefits and risks there are in gene editing, they ideally should be shared by everyone equally.

  • The regulation of gene-editing should ultimately rest in the hands of an organization of knowledgeable people (a) who are divorced from any political or financial interests in the applications of gene-editing technology, and (b) who are sensitive to the wishes and standards of the social groups they serve. A model might be the World Health Organization’s Advisory Committee on Developing Global Standards for Governance and Oversight of Human Genome Editing. (The history of humans’ attempts to regulate major technological advances does not inspire confidence; think of the development of nuclear power, and the internet and social media. One is forced to the metaphor of building the ship as you’re sailing it, perhaps the most likely view of how gene-editing technology will be handled.)



   Human Genome Editing: Science, Ethics, and Governance (2017). The National Academies Press,

   Jennifer A. Doudna and Samuel H. Sternberg  (2018). Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution. Mariner Books.

   Heritable Human Genome Editing (2020). The National Academies Press,

   Henry T. Greely (2021). CRISPR People: The Science and Ethics of Editing Humans. MIT Press.










6. Should humans have their genes edited? (short answer)  Answer: A different answer to this question (see Question 5 above) might be as follows.

   We have always tried to correct defects in our bodies’ functioning. We use a cane to assist a game leg, we wear eyeglasses to correct our vision, we employ surgery to correct cleft lip and palate. Now that we know that defective genes are the cause of many human disorders, we can try to correct those too, by editing the defective genes where possible. It is a reasonable extension of our eternal desire to decrease suffering and improve our lot.

   Aside from correcting defects, throughout history we have also extended our senses by means of microscopes, telescopes, high-speed cameras, television, CAT scans, ultrasound, and other technology. And even though there may be nothing fundamentally wrong with what Nature usually gives us, to “improve” our own bodies we undergo hair-color changes, nose jobs, breast augmentation, and facelifts. Now, in this age of genetic manipulation, and knowing that at least some traits are partially genetically determined, we naturally hope to improve ourselves by editing our genes.

   However, there are four kinds of limitation:

  • The technology is not simple to apply, at least not currently.

  • With the present state of the technology, there are bound to be some mistakes (e.g., deformed fetuses and infants); their production would be unethical.

  • The majority of traits that we might wish to improve—IQ, beauty, personality—are not completely determined by genes. Even to the extent that they are, such traits are often the outcome of complicated and currently unpredictable interactions of a great many genes during embryonic and fetal development. The results of changing any of those genes cannot be safely predicted, and the results cannot be undone after birth.

  • One may decide to have “genetic surgery” (gene editing) done on oneself, but it is not ethical to practice it on one’s embryos or infants, who have no say in the matter. If the editing of your embryo’s genes is done (the "designer babies" scenario), the editing would affect all or most cells, and the edits may eventually be transmitted to your children’s children. The long-term consequences of such practices are unpredictable.

   Therefore human enhancement by gene editing, even if the aim is to give a result that is within the bounds of what is considered normal, should, for the time being, not be attempted.

   9 June 2021.    Thanks to Serena Lurie for comments.