Birds Do It. Bees Do It. So Why Not Single Women and Lesbians?

Infertile couples have come to take assisted reproductive technologies (ART) for granted. An increasing number of single women and lesbian couples also desire to have children and turn to ART, especially donor insemination, to fulfill this desire. While most married couples find that access to ART is limited primarily by the ability to pay, for single women and lesbian couples, the story may be much different. In the United States, they may find that doctors and infertility clinics view their desires as immoral and refuse to accept them as patients, although other doctors and clinics readily accept them. In most other countries, however, it is against the law for single women and lesbian couples to make use of ART, including donor insemination.
In this paper I will argue that marital status and sexual orientation should not serve as a barrier to accessing the world of reproductive medicine. I will base this conclusion on two arguments. First, that justice requires that we treat like cases alike. Just as we would not accept or reject patients for cardiac rehabilitation programs based on factors such as a history of poor eating habits, so too we should not look at nonmedical factors such as marital status when deciding whether to treat infertility. For the second justification for the conclusion of equal access to ART, I will examine the concept of the family. I will argue that it is morally acceptable for single women and lesbian couples to have children and to head families.     

Birds do it. Bees do it. So why not single women and lesbians?

Infertile couples have come to take assisted reproductive technologies (ART) for granted. An increasing number of single women and lesbian couples also desire to have children and turn to ART, especially donor insemination, to fulfill this desire. While most married couples find that access to ART is limited primarily by the ability to pay, for single women and lesbian couples, the story may be much different. In the United States, they may find that doctors and infertility clinics view their desires as immoral and refuse to accept them as patients, although other doctors and clinics readily accept them. In most other countries, however, it is against the law for single women and lesbian couples to make use of ART, including donor insemination.
In this paper I will argue that marital status and sexual orientation should not serve as a barrier to accessing the world of reproductive medicine. I will base this conclusion on two arguments. First, that justice requires that we treat like cases alike. Just as we would not accept or reject patients for cardiac rehabilitation programs based on factors such as a history of poor eating habits, so too we should not look at nonmedical factors such as marital status when deciding whether to treat infertility. For the second justification for the conclusion of equal access to ART, I will examine the concept of the family. I will argue that it is morally acceptable for single women and lesbian couples to have children and to head families.     

Stocking the Genetic Supermarket: Reproductive Genetic Technologies and Collective Action Problems

Reproductive genetic technologies (RGTs) allow parents to decide whether their future children will have or lack certain genetic predispositions. A popular model that has been proposed for regulating access to RGTs is the ‘genetic supermarket’. In the genetic supermarket, parents are free to make decisions about which genes to select for their children with little state interference. One possible consequence of the genetic supermarket is that collective action problems will arise: if rational individuals use the genetic supermarket in isolation from one another, this may have a negative effect on society as a whole, including future generations. In this article we argue that RGTs targeting height, innate immunity, and certain cognitive traits could lead to collective action problems. We then discuss whether this risk could in principle justify state intervention in the genetic supermarket. We argue that there is a plausible prima facie case for the view that such state intervention would be justified and respond to a number of arguments that might be adduced against that view.     

Reproductive controls and sexual destiny

Murphy considers the moral implications of the future possibility that certain reproductive technologies could offer the prospect of controlling sexual orientation. He discusses three arguments for and three against prenatal intervention to ensure heterosexual progeny and to avoid homosexual progeny. Interventions would appear to be immoral if motivated by heterosexism, a doctrine asserting the superiority of heterosexuality which Murphy believes is intellectually indefensible in its premises and morally wrong in its consequences. He argues, however, against legally banning the use of interventions to determine sexual orientation because "there are important freedoms to preserve in the domain of reproductive control and because it is not clear that the use of these interventions would adversely affect the interests of existing or future persons."     

Unmanaged care: the need to regulate new reproductive technologies in the United States

In the aftermath of allegations of the misuse of human eggs in the United States, questions are being raised about whether profitable reproductive services should continue to function in a free market under the aegis of physicians or should be regulated. Other countries in which reproductive technologies are employed to a significant degree have developed regulations governing their use, many as a result of recommendations made by inter-disciplinary commissions that solicited public input. Policy makers in the United States have been reluctant to regulate reproductive technologies, however, because their use is politically controversial, they want to whittle down government, some do not consider infertility an illness, and some believe regulation would interfere with the right to reproduce. Yet the unfettered use of reproductive technologies can create such harms as lack of informed consent, providing procedures not medically indicated for financial gain, practice by unqualified personnel, injury to patients and donors, failure to screen donated gametes, and inadequate medical record keeping. Americans place special value on the welfare of children and those who bring them into the world. Such values can outweigh individual procreative liberty when new reproductive technologies are at issue. Although the optimal course would be to establish a regulatory body to govern reproductive technologies, this is not politically feasible now. The newly established National Bioethics Advisory Commission provides a forum in which issues surrounding reproductive technologies should be addressed at this time in the United States.     

Unmanaged Care: The Need to Regulate New Reproductive Technologies in the United States

In the aftermath of allegations of the misuse of human eggs in the United States, questions are being raised about whether profitable reproductive services should continue to function in a free market under the aegis of physicians or should be regulated. Other countries in which reproductive technologies are employed to a significant degree have developed regulations governing their use, many as a result of recommendations made by inter-disciplinary commissions that solicited public input. Policy makers in the United States have been reluctant to regulate reproductive technologies, however, because their use is politically controversial, they want to whittle down government, some do not consider infertility an illness, and some believe regulation would interfere with the right to reproduce. Yet the unfettered use of reproductive technologies can create such harms as lack of informed consent, providing procedures not medically indicated for financial gain, practice by unqualified personnel, injury to patients and donors, failure to screen donated gametes, and inadequate medical record keeping. Americans place special value on the welfare of children and those who bring them into the world. Such values can outweigh individual procreative liberty when new reproductive technologies are at issue. Although the optimal course would be to establish a regulatory body to govern reproductive technologies, this is not politically feasible now. The newly established National Bioethics Advisory Commission provides a forum in which issues surrounding reproductive technologies should be addressed at this time in the United States.     

GENETIC ENGINEERING TO AVOID GENETIC NEGLECT: FROM CHANCE TO RESPONSIBILITY

Currently our assessment of whether someone is a good parent depends on the environmental inputs (or lack of such inputs) they give their children. But new genetic intervention technologies, to which we may soon have access, mean that how good a parent is will depend also on the genetic inputs they give their children. Each new piece of available technology threatens to open up another way that we can neglect our children. Our obligations to our children and our susceptibilities to corresponding legal and moral sanctions may be about to explosively increase. In this paper I argue that we should treat conventional neglect and ‘genetic neglect’– failing to use genetic intervention technologies to prevent serious diseases and disabilities – morally consistently. I conclude that in a range of cases parents will have a moral obligation to use genetic treatments to prevent serious disabilities in their children. My particular focus is on prenatal interventions and their impact of the bodily integrity of expectant mothers. I conclude that although bodily integrity constrains moral obligations, it is outweighed in a range of cases.     

Body size matters in provision of help: factors related to children's willingness to help overweight peers

Although children who are overweight may be vulnerable to negative social experiences, little is known about whether children will offer help to peers who are overweight. The present study examined whether children would offer aid to peers who are overweight with everyday tasks (such as picking up toys). This study also examined whether weight stereotypes and intentions to befriend these peers are related to intentions to help. Fifty-one children, aged 4-8, were interviewed about their stereotypes and behavioral intentions. Findings revealed that children were less likely to help overweight than average weight peers. Children who did not hold positive stereotypes about thinness and those who chose to play with overweight peers were more likely to help peers who are overweight. Results suggest that weight prejudice is pervasive and that children who are overweight might not be offered aid in classroom settings, highlighting the need for early intervention.     

Germline genome editing versus preimplantation genetic diagnosis: Is there a case in favour of germline interventions?

CRISPR is widely considered to be a disruptive technology. However, when it comes to the most controversial topic, germline genome editing (GGE), there is no consensus on whether this technology has any substantial advantages over existing procedures such as embryo selection after in vitro fertilization (IVF) and preimplantation genetic diagnosis (PGD). Answering this question, however, is crucial for evaluating whether the pursuit of further research and development on GGE is justified. This paper explores the question from both a clinical and a moral viewpoint, namely whether GGE has any advantages over existing technologies of selective reproduction and whether GGE could complement or even replace them. In a first step, I review an argument of extended applicability. The paper confirms that there are some scenarios in which only germline intervention allows couples to have (biologically related) healthy offspring, because selection will not avoid disease. In a second step, I examine possible moral arguments in favour of genetic modification, namely that GGE could save some embryos and that GGE would provide certain benefits for a future person that PGD does not. Both arguments for GGE have limitations. With regard to the extended applicability of GGE, however, a weak case in favour of GGE should still be made.     

PSYCHIATRIC MANAGEMENT OF INTERSEXED PATIENTS

The psychiatric management of intersexed patients stems from an awareness that sexual identity is the result of a complex mixture of somatic and psychological components. Decisions in treatment are dependent on the appearance and correctability of the anatomic defects, the age of the patient, and the potential reversibility of the identifications contributing to the manifested sexual identity. In infants and small children, following proper diagnosis of somatic sex and an evaluation of degree of correctability of anatomical defects, decision can be made whether to bring up the child in his genetic sex or not. It is very difficult to change the sexual identity after two and a half years, except possibly in persons who already have considerable question as to their maleness or femaleness.In the psychiatric treatment of children with such disorders, the child and his family should be informed in understandable language what is being done, and the child and usually the parents should be involved in psychotherapy.With the adult, if treatment is necessary, supportive therapy, not psychoanalysis, should be used.     

The ecology and genetics of fitness in Chlamydomonas. XIII. Fitness of long-term sexual and asexual populations in benign environments

We measured the mean fitness of populations of Chlamydomonas reinhardtii maintained in the laboratory as obligately sexual or asexual populations for about 100 sexual cycles and about 1000 asexual generations. Sexuality (random gamete fusion followed by meiosis) is expected to reduce mutational load and increase mean fitness by combining deleterious mutations from different lines of descent. We found no evidence for this process of mutation clearance: the mean fitness of sexual populations did not exceed that of asexual populations, whether measured through competition or in pure culture. We found instead that sexual progeny suffer an immediate loss in fitness, and that sexual lines maintain genetic variance for fitness. We suggest that sexual populations at equilibrium with selection in a benign environment may be mixtures of several or many epistatic genotypes with nearly equal fitness. Recombination between these genotypes reduces mean fitness and creates genetic variance for fitness. This may provide fuel for continued selection should the environment change.     

Attitudes toward homosexuals: An alternative darwinian view

Gallup (1995) argued that there has been selection for parents to counter any social process that would increase the likelihood of one of their children becoming homosexual, and he indicated that contact between adult homosexuals and children was such a process. He therefore predicted (and found) that homophobia would be exaggerated where there was perceived contact with children. In this commentary, I argue that this hypothesis is based on supposing that sexual orientation occurs through a modeling process, when in fact it operates via an imprinting-like process. The specific findings regarding negative attitudes to homosexuals can be explained in terms of a more general evolved response, xenophobia. I argue that Gallup's hypothesis comes from a general willingness to view specific aspects of contemporary human behavior as adaptive when there are a number of reasons—all consistent with modern Darwinian thinking—why many of these are not themselves adaptive.     

同性恋形成的行为神经内分泌机制

本文主要从生物学角度出发,从遗传学、神经内分泌学、行为学和神经解剖学方面综述了同性恋发生的神经内分泌机制。除了遗传和环境影响之外,围产期异常的性激素环境导致了性倾向的异常。在个体发育过程中通过下丘脑-垂体-性腺轴和下丘脑-垂体-肾上腺轴的作用,性腺类固醇激素和多种神经递质相互作用调节个体的性倾向的形成。同时,本文还提出目前该领域的研究进展、有待于解决的问题,以及进一步的研究方向,希望有助于人们正确认识同性恋的发生,关注同性恋生理和心理健康,预防青少年同性恋的发生。     

Moral Enhancement and Those Left Behind

Opponents to genetic or biomedical human enhancement often claim that the availability of these technologies would have negative consequences for those who either choose not to utilize these resources or lack access to them. However, Thomas Douglas has argued that this objection has no force against the use of technologies that aim to bring about morally desirable character traits, as the unenhanced would benefit from being surrounded by such people. I will argue that things are not as straightforward as Douglas makes out. The widespread use of moral enhancement would raise the standards for praise and blame worthiness, making it much harder for the unenhanced to perform praiseworthy actions or avoid performing blameworthy actions. This shows that supporters of moral enhancement cannot avoid this challenge in the way that Douglas suggests.     

Genome structure and the benefit of sex

We examine the behavior of sexual and asexual populations in modular multipeaked fitness landscapes and show that sexuals can systematically reach different, higher fitness adaptive peaks than asexuals. Whereas asexuals must move against selection to escape local optima, sexuals reach higher fitness peaks reliably because they create specific genetic variants that "skip over" fitness valleys, moving from peak to peak in the fitness landscape. This occurs because recombination can supply combinations of mutations in functional composites or "modules," that may include individually deleterious mutations. Thus when a beneficial module is substituted for another less-fit module by sexual recombination it provides a genetic variant that would require either several specific simultaneous mutations in an asexual population or a sequence of individual mutations some of which would be selected against. This effect requires modular genomes, such that subsets of strongly epistatic mutations are tightly physically linked. We argue that such a structure is provided simply by virtue of the fact that genomes contain many genes each containing many strongly epistatic nucleotides. We briefly discuss the connections with "building blocks" in the evolutionary computation literature. We conclude that there are conditions in which sexuals can systematically evolve high-fitness genotypes that are essentially unevolvable for asexuals.     

Current and Future Use of Nematodes in Biocontrol: Practice and Commercial Aspects with Regard to Regulatory Policy Issues

Constraints about the use of chemical insecticides have limited the availability of control measures against soil-borne insect pests. Entomopathogenic nematodes of the genera Steinernema and Heterorhabditis provide an environmentally safe and economically reasonable alternative. Their life cycle and current production, storage and formulation technology are described. An overview of their safety, use in integrated pest management and current market potential (US$10 million in 1994) is also given. The costs of research and development efforts and the scale-up of production technologies are discussed in relation to the current and future market potential. Large-scale, outdoor application will require additional scientific and technical progress in the areas of production, storage, formulation and application. Besides public funding, the current niche markets will need to provide the financial basis for further development, provided that regulatory conditions will not limit the exploitation of the nematodes' market potential. It is recommended that nematodes should be exempted from registration. Rules for risk assessment in the use of exotic nematodes should be internationally harmonized and related specifically to the biology and ecology of these nematodes. The volume of current markets would not justify the costs of registration procedures currently required for chemical or microbial insecticides or genetically engineered organisms. Regulatory policies should aim at supporting the further introduction of entomopathogenic nematodes as biocontrol agents.     

Sexual Conflict over the Maintenance of Sex: Effects of Sexually Antagonistic Coevolution for Reproductive Isolation of Parthenogenesis

Sexual reproduction involves many costs. Therefore, females acquiring a capacity for parthenogenetic (or asexual) reproduction will gain a reproductive advantage over obligately sexual females. In contrast, for males, any trait coercing parthenogens into sexual reproduction (male coercion) increases their fitness and should be under positive selection because parthenogenesis deprives them of their genetic contribution to future generations. Surprisingly, although such sexual conflict is a possible outcome whenever reproductive isolation is incomplete between parthenogens and the sexual ancestors, it has not been given much attention in the studies of the maintenance of sex. Using two mathematical models, I show here that the evolution of male coercion substantially favours the maintenance of sex even though a female barrier against the coercion can evolve. First, the model based on adaptive-dynamics theory demonstrates that the resultant antagonistic coevolution between male coercion and a female barrier fundamentally ends in either the prevalence of sex or the co-occurrence of two reproductive modes. This is because the coevolution between the two traits additionally involves sex-ratio selection, that is, an increase in parthenogenetic reproduction leads to a female-biased population sex ratio, which will enhance reproductive success of more coercive males and directly promotes the evolution of the coercion among males. Therefore, as shown by the individual-based model, the establishment of obligate parthenogenesis in the population requires the simultaneous evolution of strong reproductive isolation between males and parthenogens. These findings should shed light on the interspecific diversity of reproductive modes as well as help to explain the prevalence of sexual reproduction.     

The consequences of heterogamy and homogamy on the similarity between spouses

Humans in many societies are known to mate, or marry, assortatively for a number of characters such as eye colour, height, IQ and place of birth. In this assortment an element of active choice may be involved. It is not known whether this choice is genetic. Two models of human mate choice are examined in which both males and females can express a mating preference. In the first, 'sexual' preferences can be expressed for any phenotype not necessarily one's own; in the second, preferences are only expressed for an individual's own phenotype. The results of the examination indicate how much active choice would be needed to account for the observed correlations between human mates, and suggest whether human mating preferences are more likely to be sexual or assorting.     

The Enhancement of Children versus Circumcision: A Case of Double Moral Standards?

The application of enhancement technologies to children and non‐medical infant male circumcision are both topics that enjoy the continuous attention of bioethical research but are usually discussed in isolation from each other. Yet one can show that three major arguments used by opponents of the enhancement of children are also applicable to circumcision. These arguments are based on the insecurity of these procedures, the child's right to an open future, and human nature as a foundation of human dignity. People who reject the enhancement of children because of these arguments but accept circumcision hold mutually inconsistent moral convictions or apply double moral standards to these cases. This is particularly important when legislative systems treat the enhancement of children and circumcision in a considerably different manner, which is true for many contemporary legislative systems. At least three strategies can be adopted in order to avoid such inconsistencies, two of which, however, fail for various reasons. According to a third, more promising strategy, circumcision should be subsumed under human enhancement and treated like other enhancement technologies. This strategy justifies restrictions on, but not the prohibition of circumcision. Furthermore, proponents of circumcision should be prepared for future technologies that provide similar benefits as circumcision but are not as contentious as this intervention, so that, in the future, circumcision could become more and more unacceptable.     

遗传检测综述

目前,遗传检测正在更多的国家、更广泛的范围内被采用。然而,在中国人们还不大熟悉遗传检测的原理、类型、技术、对社会的益处以及国内或国际是如何对它进行管理的。随着遗传检测的广泛使用,正确的监督显得相当必要。对近年来遗传检测所取得的进展进行了粗略的回顾,这将帮助我们对人类遗传学和分子医学革命的新时代有更多的了解。