Genetics is the field of scientific research that studies gene activity in plants, animals, and humans. Genes are segments of DNA (deoxyribonucleic acid) found in each living cell; each of these DNA segments codes for a protein, thereby yielding a phenotypic effect. All life on Earth shares the chemical make-up of DNA, even though each species differs in the number and function of genes. Scientists estimate that human DNA contains between thirty-one and thirty-six thousand genes arrayed over two pairs of twenty-three chromosomes. The forty-six human chromosomes are strands of DNA, with each of the twenty-three strand pairs arranged as a double helix. The DNA strands are composed of four base chemicals: adenine (A), guanine (G), cytosine (C), and thymine (T ). These four bases are typically identified by their single letter abbreviations (A,G,C,T ) and constitute an alphabet, so to speak, that carries genetic information from DNA to tissue formation and bodily activity.

Modern genetics began in the nineteenth century with the research of an obscure Austrian monk, Gregor Mendel (1822–1884), who discovered patterns of inheritance in pea plants. Mendelian laws of inheritance still stand as the foundation for contemporary genetics. The twentieth century added the chemical work of molecular biology, including the post World War II discovery of the double helix structure of DNA by James Watson (b. 1928) and Francis Crick (b. 1916). At the turn of the twenty-first century, the Human Genome Project had sequenced the three billion base pairs and nearly identified all the genes in the human genome. The complete genomes of a handful of plants and animals had also been identified.

In addition to molecular biology, which directly studies the chemical processes of genes, two other branches of genetics have become significant for religious reflection: behavioral genetics and sociobiology. Behavioral genetics employs statistical studies of phenotypical characteristics and social preferences to discern heritability probabilities. Central to such studies are monozygotic and heterozygotic twins raised apart. The assumption in such studies is that twins raised apart are excellent subjects because they provide opportunity to distinguish between genetic and environmental influences.

Sociobiology appeared in 1975 with publications by Harvard entomologist Edward O. Wilson (b. 1929). Wilson, having studied how ant societies are socially held together by chemical signals, purported by analogy that human breeding patterns, gender dominance, and caste systems are similarly explainable. Zoologist Richard Dawkins (b. 1941) shortly thereafter coined the term "selfish gene," which reinforced the central thesis of sociobiology. In Darwinian fashion the human organism does not live for itself; rather, its function in nature is to reproduce the genes for which it is the temporary carrier. In short, genetic forces drive evolution, including human evolution, and human social history, including religious history, can be explained by reference to genetic drives.

Theological issues raised by genetics

The apparent growth in knowledge regarding human nature cultivated by genetic research leads some religious thinkers to review their inherited anthropologies. Most theologians see the field of genetics as a challenge requiring response; a few see new genetic knowledge as a complement to long standing religious insight. Distinctively theological issues are few and are frequently embedded within the more plentiful and visible issues of ethics and public policy. Theological issues will be taken up immediately; ethical issues surrounding cloning and stem cell research will follow.

The first theological concern is genetic reductionism. Reductionism poses a theological threat everywhere in modern science. The form it takes in genetics is the vague cultural belief that "it's all in the genes." In the laboratory, methodological reductionism is necessary to foster research into gene function, but a threat comes with ontological reductionism and surmises that all of what constitutes human nature is reducible to the genes. During the early years of the Human Genome Project, DNA was described by some scientists as the "code of codes" or the "blueprint of humanity." Such biological reductionism seems to leave no room for independent influence on the part of spirit or culture, the dimensions wherein most religious traditions work.

A second and related concern is genetic determinism. If "it's all in the genes" and the DNA is the blueprint of who human beings are, then genes move into the position of determiners of human nature and human value. In the historical struggle between nature and nurture in the minds of intellectuals trying to explain human complexity, the new breed of genetic determinists stake their claim on nature. Relatively few molecular biologists advocate strong genetic determinism, whereas behavioral geneticists and sociobiologists reinforce it. Molecular biologists and philosophers who oppose an exclusive genetic determinism frequently appeal to two part determinism: genes plus environment. Some theologians locate human freedom in three part determinism: genes, environment, and the human self or person. In the latter case, the human self is emergent; the self is not reducible to either biological or environmental influences. Divine action in the human reality here is said to be holistic—that is, present to all three dimensions of biology, environment, and person.

A third and related concern is neo-Darwinian evolution. Nineteenth century Darwinism employed natural selection as the mechanism for explaining evolutionary change over time. Twentieth century neo-Darwinists such as Fransisco Ayala or Stephen Jay Gould add genetic mutation to the theory, adding detail to the manner in which natural selection works. Sociobiology extrapolates on neo-Darwinism by attempting to explain all of human culture including religious belief in terms of biological determinism. Sociobiologists (sometimes called evolutionary psychologists) contend that human culture is on a leash, a short leash, held by a genetic agenda. That agenda is the self-replication of genes using the human species as its vehicle. Human culture is structured so as to encourage reproduction and, hence, the perpetuation of genes. Human religion and human morality, whether theologians know it or not, is reducible to the agenda of selfish genes.

Those theologians who are attempting to incorporate sociobiology into their religious vision feel they must justify human transcendence of biology and the emergence of soul or spirit. Philip Hefner's theological anthropology, for example, argues that through evolutionary processes the genes have determined that we humans would be free. Some Christology's contend that Jesus marks a significant advance in evolutionary history, because with the Nazarene a precedent-setting life is led that transcends the selfish genetic agenda, and the possibility is opened for self-sacrificial loving. In contrast, some Muslim scholars find they must simply reject neo-Darwinian evolutionary theory because it makes no room for human spirit and because it fails to cohere with the anthropology of the Qur'an.

In summary, the theological community is accepting of the methodological reductionism within molecular biology that functions to yield advance in scientific research. However, theologians resist philosophical extrapolations that tend toward ontological reductionism or genetic determinism. Reductionism and determinism are insufficient, say theologians, to explain spiritual reality or ethical transcendence. Theologians defend human freedom and moral transcendence whether it complements the science or requires abandoning the science.

Genetic engineering

Genetic engineering consists of selecting, inserting, or removing individual genes in order to manipulate the genome of an organism. In agriculture and animal husbandry selective breeding to obtain preferred strains has been practiced for millennia. Modern genetic engineering adds chemical and mechanical methods for more sophisticated results.

In agriculture the genomes of plants are altered by genetic engineering to confer resistance to blight or resistance to herbicides in order to eliminate weeds while preserving the crops. Tomato genomes, for example, can be modified so as to stall final ripening during transport to market and then ripen just prior to going on sale. Such techniques dramatically increase the percentage of produce that becomes marketable. In Europe and other parts of the world popular movements against genetically modified foods (GMFs) have arisen. Fearing unknown possible health effects, opponents of GMFs lobby for accurate labeling so that the market can freely choose whether to consume them or not.

The engineering of farm animal genomes has two purposes. One is to obtain preferred strains of livestock, especially beef cattle. The other is to produce foods or pharmaceuticals for human consumption. An example of the latter case is the insertion of a human gene into a sheep genome to produce in the animal's milk a certain protein usable for treatment of a human disease. This use of animals for human betterment is itself controversial, with opponents arguing that turning animals into a means for human ends violates animal dignity.

To date, the genetic engineering of human genomes in the reproduction process has been limited to gene selection; it has not included gene insertion or removal. When in vitro multiple fertilized ova are examined, only those with the preferred genome may be implanted in the mother's uterus. This process is typically employed to eliminate known deleterious genes such as that for cystic fibrosis. In somatic therapy on living persons, however, more than selection is being tried. Genes that produce healthy blood have been inserted into bone marrow cells. Attempts are being made to send "knock out" genes into cancer tumors to turn off tumor growth by turning off telomerase activity.

An implicit theological issue that arises more often in the wider cultural debate than within specific religious communities is naturalism. Naturalism is the belief that nature apart from intervention by human technology is the source of value. Genetic engineering is a form of technology that alters the natural world people have inherited from evolutionary history. The promethean question arises implicitly: Is the natural world the source of human value, or, on the basis of humanly superimposed purposes, do people have the right to manipulate nature to meet these purposes? Much of the energy driving opposition to GMFs derives from naturalism. A similar naturalism is implicit in theological arguments, which presume that God's will is manifest in the genetic lottery resulting from sexual intercourse rather than through deliberate selection in vitro of the genetic code of future children.

The promethean question also arises with genetic futurism. As the present generation manipulates plant, animal, and human genomes, will this place humans in the position of guiding our evolutionary future? Does the human race possess the wisdom to choose a wholesome future or, like Prometheus of ancient Greek tragedy, will humans overstep their finite bounds and create an irreparable tragedy? Conservative theologians along with naturalist advocacy groups wish to put the brakes on genetic engineering and let nature take its course; whereas other religious leaders foresee immense benefits for health and wellbeing to be gained through genetic technology and contend that the human race must steward scientific advance.

Cloning

The two most virulent ethical controversies over genetic research have been cloning and stem cells. The two are linked. The first successful experiment in reproductive animal cloning was accomplished at the Roslin Institute in Edinburgh, Scotland, where embryologist Ian Wilmut cloned the world famous sheep, Dolly. The details were published in the February 27, 1997, issue of Nature. Wilmut's Roslin team removed cells from the udder of a pregnant Finn Dorset ewe, placed them in a culture, and starved them of serum nutrients for a week until the cells became quiescent—that is, they arrested the normal cycle of cell division, inviting a state akin to hibernation. Second, they took an unfertilized egg, or oocyte, from a Scottish Blackface ewe and removed the nucleus. When removing the nucleus with the DNA, they left the remaining cytoplasm intact. Third, the scientists placed the quiescent cell next to the oocyte; then they introduced pulses of electric current. The gentle electric shock caused the cells to fuse, and the oocyte cytoplasm accepted the quiescent DNA. A second electric pulse initiated normal cell division. Fourth, after six days of cell division, the merged embryo was implanted into the uterus of another Blackface ewe and brought through pregnancy to birth on July 5, 1996. The newborn babe was named Dolly. The procedure was called somatic cell nuclear transfer (NT).

An important scientific question was answered with this experiment: Is cell differentiation reversible? The answer seems to be yes. Embryonic cells are predifferentiated. Adult cells are normally differentiated in order to perform the particular tasks of particular parts of the body. For example, genes for hair are turned on in the hair while genes for toenails are turned off in hair but on where the toenails belong. In theory, cloning could be accomplished by employing embryonic cells in their predifferentiated state. The accomplishment here was to make an adult differentiated cell function as an undifferentiated embryonic cell.

The procedure was not clean and easy. The successful cloning of Dolly was accompanied by numerous misfires. Out of 277 tries, the Roslin scientists were able to make only twenty-nine embryos survive beyond six days. At fourteen days 62 percent of the fetuses in ewe wombs were lost, a significantly greater proportion than the estimate of 6 percent after natural mating. Eight ewes gave birth to five lambs, with all but one dying shortly thereafter. Dolly was the only one to survive. Triumph is accompanied by loss. Noting this, many scientists including Wilmut himself have opposed the prospect of human cloning because of the safety argument—that is, until the process is perfected, too many human embryos would be destroyed as misfires.

Ethical issues raised by cloning

Ethical issues arising from cloning technology can be divided into two areas, human reproductive cloning and human therapeutic cloning. Therapeutic cloning will be taken up later in the discussion of stem cells. The public discussion over reproductive cloning seems to focus on human reproduction, not animals. Cloned cattle and sheep do not elicit the religious opposition connected to human births.

The overriding ethical issue is this: Should human beings be cloned? Back in 1971 James Watson predicted this debate. Watson, along with Francis Crick, won the 1962 Nobel Prize for medicine or physiology for the discovery of the double helix structure of DNA. Writing on cloning for the May 1971 issue of the Atlantic, Watson predicted that the first reaction of most people to the arrival of these asexually produced children would be one of despair. He then went on to suggest that people with strong religious backgrounds would want to de-emphasize all those forms of research that would circumvent the normal sexual reproductive process. The Watson prophecy seems to have found its fulfillment.

In a February 22, 1997, press release, Donald Bruce, Director of the Society, Religion and Technology Project of the Church of Scotland, said that cloning human beings would be ethically unacceptable as a matter of principle. According to Christian belief, he said, cloning would be a violation of the uniqueness of human life, which God has given to each of us and to no one else. The argument that each individual person has a unique identity that would be violated by cloning has been repeated in religious and secular circles with a high degree of frequency.

The structure of this argument applies three assumptions to the issue of cloning. The first assumption is that in order for a human person to have an individual identity he or she must have a unique genome. The second assumption is that God has ordained that each person have a genome that differs from every other person. The third assumption is that through this genetic technology human beings could accidentally produce two persons with the same identity and, thereby, violate the divine creator's intention. On the basis of these scientific and theological assumptions, the ethical conclusion drawn here is this: no cloning.

Those holding the alternative position reject these assumptions. Scientifically speaking, even though two individuals might end up with identical genotypes, they would not end up with identical phenotypes. DNA does not always express itself in lock step fashion. There are variations in expression and spontaneous mutations. In addition, environmental factors such as food and exercise and health care influence gene activity. If the DNA donor and clone are reared a generation apart in time let alone in separate locations, similarities will be noticeable, but differences will abound.

The existence of monozygotic twins is instructive. Like clones, identical twins are born with identical genomes. Despite what they share in common, they grow up as separate and distinct individuals. Each has his or her own interior consciousness, sense of self, thought processes, and ethical responsibility. Even if studies in behavioral genetics eventually show strong DNA influence on predispositions to certain forms of behavior, they remain two separate individuals with separate lives to lead. A clone would in effect be a delayed twin; due to the delay, a clone would probably experience even more independence than two born at the same time.

During the debate, the question arose: Would two clones share a single soul? No theological position to date has held that two twins share a single soul. Each has his or her own soul, his or her own connection to God. This by analogy would seem to apply to clones as well. The human soul, theologically speaking, is not formed from DNA as the phenotype is formed from the genotype. The soul is not a metaphysical appendage to the physical. In sum, the theological argument against cloning based on an alleged violation of a God-given identity appeared early in the debate but eventually dissipated under critical review.

The United States National Bioethics Advisory Commission (NBAC) studied cloning—a study that included interviews with leaders in Judaism, Islam, Hinduism, Buddhism, Evangelical Protestantism, Liberal Protestantism, and Roman Catholicism—and issued a report on June 6, 1997, with the following conclusion: At this time it is morally unacceptable for anyone in the public or private sector, whether in a research or clinical setting, to attempt to create a child using somatic cell nuclear transfer cloning. The principle argument against cloning was the safety argument, as enunciated above by Ian Wilmut. The report went on to ask the U.S. Congress to pass legislation setting a three to five year moratorium on the use of federal funding in support of human cloning, and it asked non-federally funded private sectors to comply voluntarily with this moratorium. The NBAC further recommended that religious groups carry on an ongoing discussion of the ethics of cloning. Even though legislation did not follow, religious groups have carried on the recommended discussion.

In addition to the safety and the identity arguments, a third has been raised against human reproductive cloning: the commodification argument. Cloning—as a form of designer baby making—might lead to the commodification or commercialization of children; this would constitute an assault on a child's dignity. Dignity in this case is not based upon genetic individuality but upon treatment as an end rather than a means. Designer babies serve the ends of the designers, the parents, not the ends of the child. Cloning along with other genetic technologies, critics fear, may play into the hands of economic forces that will tend to commodify newborn children. Commodification, not genetic uniqueness, would deny the sacred character of human individual life.

Stem cells

The cloning controversy deals primarily with human reproduction. The stem cell controversy moves into therapeutic cloning and related matters. The therapeutic promise is dramatic. Specifically, rejuvenation through transplantation of tissue grown in a laboratory from stem cells would be of enormous value for cardiomyocytes to renew heart muscle to prevent congestive heart failure; replacement of hematopoietic stem cells for producing healthy blood in bone marrow to resist infection by the HIV virus and to treat AIDS and possibly sickle cell anemia; cultivating endothelial cells to reline blood vessels as treatment for atherosclerosis, angina, and stroke due to arterial insufficiency; rejuvenating islet cells in the pancreas to produce natural insulin to fight diabetes; renewal of neurons in the brain to treat Parkinson's disease and victims of stroke; fibroblast and keratinocyte cells to heal skin in the treatment of burns; and chondrocytes or cartilage cells to treat osteoarthritis or rheumatoid arthritis. All this promise arises from human embryonic stem cells (hES cells), which are self-renewing—virtually immortal—and have the capacity to develop into any or all tissue types in the human body.

Two momentous laboratory discoveries are relevant. First is the isolation of human embryonic stem cells (hES cells) in August 1998 by James Thomson, an associate veterinarian in the University of Wisconsin's Regional Primate Research Center. Thomson began with fertilized ova—spare embryos from in vitro fertilization (IVF) not placed in a uterus—and cultured them to the blastocyst stage, about four to six days. At this point he removed the outer shell of the blastocyst, separated out the individual cells, and placed them on a feeder tray. The cells divided. They reproduced themselves. Because these cells are as yet undifferentiated—that is, they are pluripotent and able to make any part of a human body—they are the cells from which other cells stem. Because they replicate themselves indefinitely, Thomson in effect created an immortal line of embryonic stem cells.

Second, John Gearhart, a professor of gynecology and obstetrics at Johns Hopkins University School of Medicine, drew human embryonic germ cells (hEG cells) from fetal gonadal tissue in September 1998. These cells, when taken from an aborted fetus, resemble in nearly all respects the pluripotent stem cells described above.

It is not yet clear whether or not hES cells are identical to hEG. Both are pluripotent and equivalent in function. Yet, it may be discovered that different alleles appear in different hES, because hES cells could be imprinted by either the male or female source. The blastocyst stage of embryogenesis is a stage that avoids the gender imprint. What is not yet known is whether original gender imprint will matter. For the foreseeable future the two types of stem cells will be treated the same, yet controversy rages over Thomson's destruction of the blastocyst to obtain hES cells.

One goal of the research agenda is to learn just what turns genes on and off. Once scientists have gained the knowledge of triggering gene expression, they can apply it to pluripotent stem cells and direct the growth of selected bodily tissue. Particular organs could be grown in culture. Heart tissue or entire organs such as the pancreas or liver could be grown in the laboratory. These would be healthy rejuvenating organs ready for transplantation.

In order to transplant the laboratory grown organs, however, medical scientists need to override our immune system in order to avoid organ rejection. Two scenarios lie before us. One would be to create a universal donor cell that would be compatible with any organ recipient. The task here would be to disrupt or alter the genes within the cell responsible for the proteins on the cell's outer surface that label them as foreign to the recipient's immune system. This approach would be difficult. It would involve disrupting genes within the same DNA in which researchers are trying to express certain other genes. Exposing such cells to harsh conditions with rounds of different drugs may damage more than just the targeted surface proteins.

A preferable second scenario would be to make cells that are genetically compatible (histo-compatible) with the organ recipient—that is, to make cells with an identical genotype. If the organ genotype matches that of the recipient, no immune system rejection will take place.

This is the connection to cloning, or somatic cell nuclear transfer. One hypothetical scenario is to begin with an enucleated human oocyte, an egg with the DNA nucleus removed. Via somatic nuclear transplantation—cloning—one could insert the DNA nucleus of the future transplant recipient. By turning on selected genes, selected tissue could be grown ex vivo, outside the body, and then through surgery placed within the recipient. Because the implanted heart or liver tissue has the same genetic code as the recipient, no rejection would occur. This is in part the Dolly scenario, although it differs in that it grows only organ tissue and not an entire fetus.

Another variant or second scenario distinguishes itself sharply from Dolly, namely, one that eliminates the use of a fresh oocyte. Instead of an oocyte, the recipient's DNA nucleus would be placed in a non-egg cell, in the stem cell itself. The goal here would be to accomplish laboratory organ growth in a stem cell that is not an egg. To accomplish this, further research on cytoplasm's role in gene expression is required, as well as development of the nuclear transfer technology for insertion into the tiny stem cell.

Ethical issues raised by stem cells

On August 9, 2001, U.S. President George W. Bush announced that his government would support research on existing lines of stem cells, but would refrain from supporting the destruction of embryos to create new cell lines. The president thought he was settling an ethical dispute. Public policy, science, and ethics are inextricable.

Formulating the central ethical question raised by stem cell research is difficult because each of the two sides is oriented toward a different question. The embryo protection position begins with the question: How can we protect the dignity of the embryo? The beneficence or healing opportunity position begins with the question: How can scientific research lead to advances in human health and well-being? Each position is internally coherent, yet they are locked in controversy.

Those holding the embryo protection position lift their voices in defense of the apparently helpless embryo threatened with death at the hands of the laboratory executioner. The use of blastocysts and aborted fetuses leads opponents to criticize the scientific community for devaluing human life. They argue that the devaluation of humans at the very commencement of life encourages a policy of sacrificing the vulnerable, and this could ultimately put other humans at risk, such as those with disabilities and the aged, through a new eugenics of euthanasia. Pope John Paul II (1978–), in an elocution at Castel Gandolpho in August 2001, likened the destruction of blastocysts to obtain hES cells with infanticide. In effect, the embryo protection position sees the stem cell debate in terms of the abortion debate.

The major premise of this position is that each human embryo is the tiniest of human beings. The unspoken second premise is that, because an embryonic stem cell is a tiny human being, it has dignity. And, having dignity, the embryo providing the stem cell deserves protection from scientists who would use the name of medical research to destroy it. The nonmalificence or "do no harm" medical maxim applies here, and this maxim is violated in embryonic stem cell research.

In contrast, the healing opportunity position notes that the principle of beneficence goes beyond that of nonmalificence. Beyond avoiding harm, appeal to beneficence requires the active pursuit of human health and wellbeing. The central focus here is the good promised by stem cell research. Beneficence is a form of agape, selfless love. Decisive in the thinking of Christian supporters of medical research is Jesus' own ministry of healing, which set an example for his disciples. In many cities Christian groups have named their hospitals "Good Samaritan" after the key figure in one of Jesus' parables who administered healing to an abandoned victim of violence. From this perspective, secular medical research contributes to God's healing work on earth.

Embryo protectors accuse beneficence supporters of crass utilitarianism, of sacrificing innocent human beings in vitro for future hospital patients. Stem cell supporters repudiate the charge of utilitarianism, some even conceding the possibility of dignity applied to the early embryo. Relevant here is the observation that hES cells are derived from surplus embryos, from fertilized ova discarded in clinics. Such surplus embryos are slated for destruction in any case, either due to freezer burn or overt disposal. The beneficence position does not necessarily endorse the actual creation of new embryos for sacrifice to laboratory research; rather, it is satisfied with drawing some life-giving potential from an entity otherwise marked for disposal. Rather than deny dignity to the early embryo, beneficence advocates believe they can affirm embryo dignity yet still sustain justification for proceeding with health yielding research on stem cells.

The deliberate creation of fresh embryos for destruction in the laboratory would require an additional premise to attain ethical justification. The additional premise could be supplied by the developmentalists. Ethicists holding the developmentalist position frequently apply the fourteen-day rule. This is based on the observation that until an embryo attaches itself to the uterine wall and gastrulation occurs, a single individual fetus is not yet formed. Twining can still occur up until the appearance of the primitive streak that will become the backbone, thereby defining a single individual rather than multiple fetuses. By denying individuality to the embryo prior to the fourteenth day, some ethicists justify research at prior stages of development. Stem cells are harvested between the fourth and sixth days.

The Vatican has steadfastly rejected the fourteen-day rule. Donum Vitae in 1987 and subsequent papal elocutions have reiterated the classic doctrine of creationism and applied it to the socalled moment of conception. When the sperm fertilizes the egg during sexual intercourse, says Pope John Paul II, a third factor is present. God imparts a freshly created soul to the zygote. The presence of this eternal soul establishes personhood and dignity to the embryo. This makes it morally inviolable and, hence, protectable.

Genetics, culture, and religion

With the field of genetics the unavoidable inter-penetration of science, culture, and religion becomes visible. Laboratory researchers cannot separate their daily work from wider cultural interpretations, and the wider culture in this case has elected to interpret genes deterministically. Theologians, who represent the intellectual segment of religious traditions, find themselves simultaneously listening to the bench scientists and the wider cultural cacophony, trying to respond to both. The pressure is increased by the demand from the political sector to establish public policy regarding what is permissible in basic research and resulting medical technology. Society cannot do without either the scientists or the theologians.

See also BEHAVIORAL GENETICS; BIOTECHNOLOGY; CLONING; DNA; EUGENICS; FREEDOM; GENE THERAPY; GENETICALLY MODIFIED ORGANISMS; GENETIC DEFECT; GENETIC DETERMINISM; GENETIC ENGINEERING; GENETIC TESTING; HUMAN GENOME PROJECT; MEMES; MUTATION; NATURALISM; NATURE VERSUS NURTURE; SELFISH GENE; SOCIOBIOLOGY; STEM CELL RESEARCH

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