This chapter contains section titled: Two Kinds of Eugenics Technological Possibilities Moral Perplexities Hither Posthumanity?

In this article I examine a recent approach to regulating assisted reproduction, whereby use of some kind of medical intervention ‘triggers’ laws governing legal parenthood that are more favourable to intending parents and sperm providers. I argue that although perhaps an improvement on the previous legal framework, these laws are problematic for three important reasons. First, they are prone to violating parental rights and unjustly imposing substantial burdens on individuals. Second, they are discriminatory. Third, even if we take a (...) pragmatic approach to the question of parenthood in these cases, these laws fail to properly consider the welfare interests of children. Finally, I conclude by showing that my argument does not entail adopting a laissez-fair attitude to conception using third-party sperm. (shrink)

Don Marquis argues that abortion is prima facie seriously wrong because it deprives the foetus of a valuable future. This paper argues that there is no morally relevant difference between the relations that foetuses stand in to valuable futures and those that gametes stand in to such futures. Therefore, Marquis’ account implies that contraception is prima facie seriously wrong. My argument for this conclusion has a significant advantage over existing criticisms of Marquis based on controversial accounts of personal identity. It (...) shows that the problem with his account is not his view that identity across time is a matter of merely biological relations, but his investment of those relations with moral significance. This criticism has force no matter which account of personal identity is true. (shrink)

Sperm donation is a widely accepted and increasingly common practice. In the standard case, a sperm donor sells sperm to an agency, waives his parental rights, and is absolved of parental responsibility. We tend to assume that this involves no problematic abandonment of parental responsibility. If we regard the donor as having parental responsibilities at all, we may think that his parental responsibilities are transferred to the sperm recipients. But, if a man creates a child accidentally, (...) via contraception failure, we tend to assume that the man does indeed have parental responsibilities. Assessing these contrasting conclusions requires a theory of parental responsibility. I analyze prevalent theories of what makes someone parentally responsible and show that none of these theories can withstand scrutiny. I propose a new theory of parental responsibility, which, I argue, is more plausible than the alternatives. My theory of parental responsibility is based on our ownership and control over hazardous materials, namely, our gametes. I show that neither my theory, nor the theories I reject, can support our contrasting intuitions. I conclude that sperm donors are fathers, with parental responsibility. I argue that the alternative conclusion, that neither sperm donors nor accidental fathers are parentally responsible for their resulting offspring, is less plausible. I then consider whether parental responsibility can be transferred and argue that it is far from clear that it can. Finally, I address objections and consider some practical implications of these views. (shrink)

BackgroundHuman female orgasm is a vexed question in the field while there is credible evidence of cryptic female choice that has many hallmarks of orgasm in other species. Our initial goal was to produce a proof of concept for allowing females to study an aspect of infertility in a home setting, specifically by aligning the study of human infertility and increased fertility with the study of other mammalian fertility. In the latter case - the realm of oxytocin-mediated sperm retention (...) mechanisms seems to be at work in terms of ultimate function while the proximate function remains unresolved.MethodA repeated measures design using an easily taught technique in a natural setting was used. Participants were a small, non-representative sample of females. The introduction of a sperm-simulant combined with an orgasm-producing technique using a vibrator/home massager and other easily supplied materials.ResultsThe sperm flowback (simulate... (shrink)

In Denmark and Sweden sperm donation is the most debated and contested of the reproductive technologies that are currently in use. Although the two countries are neighbouring welfare states with public healthcare in common, policies and practices of sperm banking and sperm donation differ strongly. Drawing on ethnographic fieldwork, this article explores how the sperm used for donor insemination is narrated, chosen, produced and consumed at sperm banks in Denmark and Sweden.The analysis illustrates that marginalization (...) and stigmatization of infertile men, donors, single women, lesbians and donor children not only takes place in the media and during debates in the Danish and Swedish parliaments where the technology has historically been contested, but also at the sperm banks and fertility clinics. This article therefore calls for more inclusive stories on sperm donation to be narrated. (shrink)

Sperm donation is an increasingly common method of assisted reproduction. In the debate on sperm donation, the right to privacy — construed as a right that refers to the limits of the realm of information to which others have access — plays a pivotal role with regard to two questions. The first question is whether the sperm donor’s right to privacy implies his right to retain his anonymity, the second is whether the gamete recipients’ right to privacy (...) entitles them to withhold information about the circumstances of their conception from their donor-conceived offspring. In this contribution, I tackle these two interrelated questions. In part, I defend the view that there is a prima facie right of sperm donors to remain anonymous. Part widens the perspective by taking into consideration the welfare of donor-conceived offspring. I argue that anonymity may harm the child only if the gametes’ recipients decide to disclose information about the circumstances of her birth to the child. Non-disclosure of these circumstances, however, is morally problematic because it may not necessarily harm, but wrong the child. In section, I attempt to rebut some arguments in defense of non-disclosure. In part, I defend the view that the best practice of sperm donation would be ‘direct donation’, i.e. that the identity of the donor is known from the time of conception. Part concludes. (shrink)

An important feature of male fertility is the physiological priming of spermatozoa by a multifaceted process collectively referred to as capacitation. The end point of this evasive process is the hyperactivated spermatozoa capable of binding to terminal sugar residues on the egg's extracellular coat, the zona pellucida (ZP), and undergoing acrosomal exocytosis (i.e., induction of the acrosome reaction). The hydrolytic action of acrosomal enzymes released at the site of zona binding, along with the enhanced thrust generated by the hyperactivated beat (...) pattern of the bound spermatozoa, are important factors that regulate the penetration of ZP and fertilization of the egg. Despite many advances in identifying sperm components that promote capacitation, the mechanism underlying the calcium‐triggered process remains elusive. The purpose of this review article is to focus on new advances that have enhanced our understanding of in vivo/in vitro capacitation, a prerequisite event resulting from a dramatic modification and reorganization of the sperm membrane molecules. Special emphasis has been laid on accumulating evidence suggesting potential similarities between the sperm capacitation and early phases of calcium‐triggered membrane fusion (i.e., tethering and docking) during secretory and endocytotic pathways among eukaryotes. BioEssays 26:281–290, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

There has been a great deal of discussion about the ethical implications of donating sperm and of the ways in which donated tissue is presented, selected, and sold for use in assisted reproduction. Debates have emerged within the academic sphere, from donor offspring and recipients, and in broader popular culture, including questions about the commodification of human tissue and the eugenic potential of selecting donors from particular demographic categories. However, the voices of donors themselves on this subject have been (...) largely silent. This paper draws on data from qualitative interviews with men who donated at a major Danish sperm bank between 2012 and 2013. It argues that many of them are indeed thinking through these complex issues. Donors’ approaches to ethical issues fell into two broad ‘types’: a pragmatic, individualistic approach which focused on more immediate personal consequences, and an ethically-driven approach in which donors considered the impact of donation on offspring and on a wider societal level. (shrink)

To whom do sperm and ova belong? Few tissues are produced by the human body with more waste than the germ cells. Yet dominion over the germ cells, and over the early embryo that results from their union in vitro, is behind much of the emotion that modern reproductive intervention can engender. The germ cells differ from other human tissues that can be donated or transplanted because they carry readily utilizable genetic information. Eventual expression of the germ cells' genetic (...) potential is the legitimate concern and responsibility of their donors, although in the right circumstances the responsibility can by agreement be entrusted to institutions administering gamete or embryo donor programmes; these institutions, in turn, may need to assume responsibility for decisions if, in the case of embryo storage, the wishes of the two donors conflict. The fact of sperm and ovum ownership (and the genetic potential that goes with it) before individuals part with these tissues is beyond dispute. Some contentious issues may be clarified if this area of human dominion, namely control over genetic expression among offspring, is acknowledged to be the legitimate persisting concern of those who have produced sperm and ova after storage commences. (shrink)

Anonymous sperm donation offspring often yearn for information about their biological fathers, and as they come of age that yearning increases in intensity. We first explore will and interest theory regarding this desire to know one’s heritage and argue that both theories lead to a right of the offspring to know. We then turn to the donor contract, look at the inconsistencies between donor ability to eschew parental responsibility compared to other biological fathers, and argue that there should be (...) a procedure similar to adoption procedures, whereby sperm donors take seriously the legal severing of their parental rights and responsibilities. We conclude that the offspring have a right to their genetic heritage and call for caring reproductive technological practices that ensure children of donors this right. (shrink)

The advent of simple in vitro fertilisation techniques has provided the reproductive biologist with an invaluable system for assaying sperm fertilising ability. In particular, they provide a useful way of identifying and characterising gamete‐specific proteins that play a role in sperm‐egg interactions, and in recent years, a growing number of sperm surface proteins have been identified that appear to be involved in these processes. Fertilin β was one of the first sperm membrane proteins to be implicated (...) in egg interactions and it has been proposed that this is mediated by means of binding of its disintegrin‐like domain to cognate integrin receptors on the egg plasma membrane. A recent paper in Science by Cho and colleagues [Cho et al. 1998. Fertilisation defects in sperm from mice lacking fertilin β. Science 281:1857–1859 (Ref. 1)] provides preliminary data on a fertilin β knockout mouse. Whilst fertilin βnull males had greatly reduced fertility, somewhat surprisingly, this could be largely attributed to causes other than impaired binding to the egg plasma membrane. BioEssays 21:183–187, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

A case is described of a man who discovered years after donating sperm for artificial insemination, that he had a serious genetic disease, autosomal dominant cerebellar ataxia . This manifests itself only years after puberty and occurs in 50% of the progeny. The sperm had been used for the conception of 18 children in 13 women. The parents were only told three years after the insemination. This long time interval was unavoidable since many of the parents had to (...) be found and the hospital director wished first to discuss the matter with his legal advisors and other experts.In future, in agreement with the new law only 10 inseminations will take place with sperm from one donor. This will reduce still further the availability of donor sperm. (shrink)

A case is described of a man who discovered years after donating sperm for artificial insemination, that he had a serious genetic disease, autosomal dominant cerebellar ataxia . This manifests itself only years after puberty and occurs in 50% of the progeny. The sperm had been used for the conception of 18 children in 13 women. The parents were only told three years after the insemination. This long time interval was unavoidable since many of the parents had to (...) be found and the hospital director wished first to discuss the matter with his legal advisors and other experts.In future, in agreement with the new law only 10 inseminations will take place with sperm from one donor. This will reduce still further the availability of donor sperm. (shrink)

Schmitt recognized that research is needed to identify other factors associated with sex ratio and with sociosexuality that may explain cross-cultural variation in sexual behavior. One such factor may be the risk of sperm competition. Sperm competition theory may lead us to a more complete explanation of cultural variation in sexual behavior.

The patient was a 19-year-old man who was the victim of an accidental head injury. The attending neurosurgeon felt that, due to uncontrollable and repeated elevated intracranial pressures, the patient would die within 48 hours. The patient's mother requested that the neurosurgeon contact a urologist to collect the patient's sperm for implantation into the patient's girlfriend. The neurosurgeon felt that the situation raised a number of ethical issues and requested that the hospital's bioethics committee consider the case.

Recent developments in studies of sperm‐mediated gene transfer (SMGT) now provide solid ground for the notion that sperm cells can act as vectors for exogenous genetic sequences. A substantive body of evidence indicates that SMGT is potentially useable in animal transgenesis, but also suggests that the final fate of the exogenous sequences transferred by sperm is not always predictable. The analysis of SMGT‐derived offspring has shown the existence of integrated foreign sequences in some cases, while in others (...) stable modifications of the genome are difficult to detect. The appearance of SMGT‐derived modified offspring on the one hand and, on the other hand, the rarity of actual modification of the genome, suggest inheritance as extrachromosomal structures. Several specific factors have been identified that mediate distinct steps in SMGT. Among those, a prominent role is played by an endogenous reverse transcriptase of retrotransposon origin. Mature spermatozoa are naturally protected against the intrusion of foreign nucleic acid molecules; however, particular environmental conditions, such as those occurring during human assisted reproduction, can abolish this protection. The possibility that sperm cells under these conditions carry genetic sequences affecting the integrity or identity of the host genome should be critically considered. These considerations further suggest the possibility that SMGT events may occasionally take place in nature, with profound implications for evolutionary processes. BioEssays 27: 551–562, 2005. © 2005 Wiley periodicals, Inc. (shrink)

This study investigates changes in sexual motivation over the duration of a partnership in a population sample stratified by age. The results replicate and extend the findings of a previous study that was based on a sample of college students. In the samples of 30- and 45-year-olds, male sexual motivation remains constant regardless of the duration of the partnership. Female sexual motivation matches male sexual motivation in the first years of the partnership and then steadily decreases. In the sample of (...) 60-year-olds, male sexual motivation always exceeds female sexual motivation, and both are little affected by duration of the partnership. This pattern is clearly evident for some measures of sexual motivation and less so or not at all for others. Interpretations of the current results from social constructivism or from mainstream psychology are difficult to conceive. The results seem more intelligible from an evolutionary perspective as reflections of evolved design for sexual motivation, fine-tuned to the different conditions governing the reproductive success of males and females. In this view male sexual motivation promotes a constant frequency of copulation in order to guard against cuckoldry. Female sexual motivation, in contrast, promotes copulation to solve the adaptive problem of procuring male resources by establishing and maintaining a pair bond. (shrink)

The motives and consequences of harvesting sperm from brain dead males for the purpose of effecting post mortem fatherhood are examined. I argue that sperm harvesting and post mortem fatherhood raise no harms of a magnitude that would justify forbidding the practice outright. Dead men are not obviously harmed by the practice; children need not be harmed by this kind of birth; and the practice enlarges rather than diminishes the reproductive choices of surviving partners. Certain ethical and legal (...) issues nevertheless require attention. As a matter of consistency with other harvesting protocols, there ought to be a mechanism for respecting the wishes of men who when alive do not wish to become fathers post mortem. Mechanisms governing entitlement to harvest and use sperm will also be required. I note that the law is unlikely to recognize the paternity of children born from harvested sperm, though there may be reasons to recognize that paternity in some instances. (shrink)

The motives and consequences of harvesting sperm from brain dead males for the purpose of effecting post mortem fatherhood are examined. I argue that sperm harvesting and post mortem fatherhood raise no harms of a magnitude that would justify forbidding the practice outright. Dead men are not obviously harmed by the practice; children need not be harmed by this kind of birth; and the practice enlarges rather than diminishes the reproductive choices of surviving partners. Certain ethical and legal (...) issues nevertheless require attention. As a matter of consistency with other harvesting protocols, there ought to be a mechanism for respecting the wishes of men who when alive do not wish to become fathers post mortem. Mechanisms governing entitlement to harvest and use sperm will also be required. I note that the law is unlikely to recognize the paternity of children born from harvested sperm, though there may be reasons to recognize that paternity in some instances. (shrink)

This paper analyses the forgotten concept of “sperm-force” proposed by George Newport (1803–1854). Newport is known for his comprehensive microscopic examinations of sperm and egg interaction in amphibian fertilization between 1850 and 1854. My work with archival sources reveals that Newport believed fertilization was caused by sperm-force, which the Royal Society refused to publish. My reconstruction chronologically traces the philosophical and experimental origins of sperm-force to Newport’s 1830s entomological work. Sperm-force is a remnant of Newport’s (...) speculations on the creation of the active individual. I argue that sperm-force was rooted in British interpretations of German _Naturphilosophie_, which demonstrates Continental influences on mid-Victorian embryology, particularly the role of male generative power. This context provides further evidence that British versions of Romantic science fostered sophisticated experimental work. The refusal by Paleyite stalwarts of natural theology to publish Newport’s ideas illustrates the institutional resistance to German pantheistic and vitalistic influences. This reconstruction of sperm-force’s philosophical foundation and its reception offers new understandings of mid-Victorian attitudes toward the inheritance of mind and body. It situates Newport’s work within the nineteenth century’s scientific project to assign stereotypical genders to the gametes. (shrink)

The motives and consequences of harvesting sperm from brain dead males for the purpose of effecting post mortem fatherhood are examined. I argue that sperm harvesting and post mortem fatherhood raise no harms of a magnitude that would justify forbidding the practice outright. Dead men are not obviously harmed by the practice; children need not be harmed by this kind of birth; and the practice enlarges rather than diminishes the reproductive choices of surviving partners. Certain ethical and legal (...) issues nevertheless require attention. As a matter of consistency with other harvesting protocols, there ought to be a mechanism for respecting the wishes of men who when alive do not wish to become fathers post mortem. Mechanisms governing entitlement to harvest and use sperm will also be required. I note that the law is unlikely to recognize the paternity of children born from harvested sperm, though there may be reasons to recognize that paternity in some instances. (shrink)

Men who spend a greater proportion of time apart from their female partner since the couple’s last copulation are at greater “objective” sperm competition risk. We propose a novel cue to sperm competition risk: the time she spends with her male friends. Four hundred and twenty men in a committed, heterosexual, sexual relationship completed a questionnaire. The results indicate that men at greater objective sperm competition risk report less time desired until the couple’s next copulation, greater interest (...) in copulating with their partner, and greater anger, frustration, and upset in response to their partner’s sexual rejection, but only among men whose partner spends more time with her male friends. These results remain after controlling statistically for the participant’s age and their partner’s age. We discuss limitations of the current research, and discuss how research in human sperm competition can inform social issues, including men’s partner-directed sexual coercion. (shrink)

Sperm sharing arrangements involve a man (‘the sharer’) allowing his sperm to be used by people seeking donor sperm (‘the recipients’) in exchange for reduced price in vitro fertilisation. Clinics in the UK have offered egg sharing since the 1990s and the arrangement has been subjected to regulatory oversight and significant ethical analysis. By contrast, until now no published ethical or empirical research has analysed sperm sharing. Moreover the Human Fertilisation and Embryology Authority (HFEA) does not (...) record the number of sperm sharing arrangements taking place.This paper describes the sperm sharing process providing an analysis of all the UK clinics advertising sperm sharing services. The ethical rationale for egg sharing is described: reducing the number of women exposed to the risks of stimulation and retrieval. This advantage is absent in sperm sharing where donation has no physical drawbacks. The key adverse social and emotional outcome of gamete sharing arises when the sharer’s own treatment is unsuccessful and the recipient’s is successful. This outcome is more likely in sperm sharing than in egg sharing given sperm from sharers can be used by up to 10 families whereas shared eggs only go to one other family.Given its morally relevant differences from egg sharing, sperm sharing requires its own ethical analysis. The HFEA should begin recording sperm sharing arrangements in order to enable meaningful ethical and policy scrutiny. (shrink)

Over the past years, a growing number of countries have legislated open-identity donation, in which donor-conceived offspring are given access to the donor’s identity once the child has reached maturity. It is held that donor anonymity creates identity problems for such children similar to the “genealogical bewilderment” described within the adoption context. The study of the social and psychological effects of open-identity donation is still very much in its infancy, but what has been left unquestioned is whether offering access to (...) the donor’s name and address is an adequate response to such effects. This study has two goals: First, we aim to provide a systematic review of the reasons why donor-conceived offspring want to know the identity of their sperm donor. Second, we examine to what extent the provision of donor-identifying information can satisfy the reasons mentioned. The most important motivations appear to be: to avoid medical risks and consanguineous relationships; to satisfy curiosity; to learn more about the self or to complete one’s identity; to learn more about what kind of person the donor is ; to form a relationship with the donor and/or his family; and to learn about one’s ancestry/genealogy. Our analysis shows that for nearly all of these reasons access to the donor’s identity is not necessary. In those cases where it is, moreover, donor identification is not sufficient. What is really needed is contact with the donor, rather than the mere provision of his name. (shrink)

In our paper ‘The ethical case for non-directed postmortem sperm donation’ we argued that it would be ethical for men to donate sperm after death for use by strangers. In their thoughtful response Fredrick and Ben Kroon lay out practical concerns regarding our proposal. They raise issues regarding the quality of sperm collected postmortem based on empirical studies. Second, they claim that concerns about quality would make women unlikely to use sperm collected after death. In this (...) response we explore issues of sperm quality in both living and dead donors. We consider whether there might be ways to ensure quality in both. Finally, we question whether quality should be a barrier to women choosing to use sperm donated after death. (shrink)

Assisted Reproductive Technologies (ARTs) have been practiced in Islamic societies within married couples since their introduction. However, there are divergent views over the issue of third-party donation among Sunni and Shia scholars. This paper illustrates the different perspectives of Shia Muslims surrounding, sperm, egg, and embryo donation and ethical aspects thereof. The study reveals that there are different views regarding sperm, egg, and embryo donation among the Shia religious leaders around the world. Many Shia religious scholars, including the (...) Iranian supreme religious leader Ali Hussein Khamenei allow sperm, egg, and embryo donation with certain conditions. However, the conditions stipulated by Shia religious scholars contradict the ethical and legal practices of sperm, egg, and embryo donation. Regarding sperm and egg donation, they declared that the donor child would inherit from a third-party donor and the commissioning parents would be adoptive parents. Thus, according to them, donor anonymity is impossible. Moreover, the Iranian act on embryo donation did not stipulate the right and responsibilities of the donor child and recipient couples and did not clarify the nature and number of embryos that can be donated and implanted. The paper argues that the lack of laws and guidelines on sperm, egg, and embryo donation raises many ethical problems. Based only on religious rulings, third-party donation has been practiced without foreseeing the well-being and safety of donor children, donors, and recipient couples. (shrink)

In their recent ‘The ethical case for non-directed postmortem sperm donation’, Hodson and Parker outline and defend the concept of voluntary non-directed postmortem sperm donation, the idea that men should be able to register their desire to donate their sperm after death for use by strangers since this would offer a potential means of increasing the quantity and heterogeneity of donor sperm. In this response, we raise some concerns about their proposal, focusing in particular on the (...) fact that current methodologies do not make for a reliable way of ensuring that sperm retrieved postmortem has a good chance of leading to conception, which is in turn likely to make potential recipients reluctant to use such sperm. These concerns add to the ethical doubts that attend aspects of the proposal, making the prospect of implementation of such a policy unlikely at best. (shrink)

A case is described of a man who discovered years after donating sperm for artificial insemination, that he had a serious genetic disease, autosomal dominant cerebellar ataxia. This manifests itself only years after puberty and occurs in 50% of the progeny. The sperm had been used for the conception of 18 children in 13 women. The parents were only told three years after the insemination. This long time interval was unavoidable since many of the parents had to be (...) found and the hospital director wished first to discuss the matter with his legal advisors and other experts.In future, in agreement with the new law only 10 inseminations will take place with sperm from one donor. This will reduce still further the availability of donor sperm. (shrink)

The past 50 years have seen heated debate in the reproductive sciences about global trends in human sperm count. In 2017, Levine and colleagues published the largest and most methodologically rigorous meta-regression analysis to date and reported that average total sperm concentration among men from ‘Western’ countries has decreased by 59.3% since 1973, with no sign of halting. These results reverberated in the scientific community and in public discussions about men and masculinity in the modern world, in part (...) because of scientists’ public-facing claims about the societal implications of the decline of male fertility. We find that existing research follows a set of implicit and explicit assumptions about how to measure and interpret sperm counts, which collectively form what we term the Sperm Count Decline hypothesis (SCD). Using the study by Levine and colleagues, we identify weaknesses and inconsistencies in the SCD, and propose an alternative framework to guide research on sperm count trends: the Sperm Count Biovariability hypothesis (SCB). SCB asserts that sperm count varies within a wide range, much of which can be considered non-pathological and species-typical. Knowledge about the relationship between individual and population sperm count and life-historical and ecological factors is critical to interpreting trends in average sperm counts and their relationships to health and fertility. (shrink)

Postmortem sperm donation implies the acceptance of a very low sperm quality threshold. This threshold has two important consequences: recipients will have to submit to burdensome and expensive in vitro fertilisation/intracytoplasmic sperm injection, and many more living donors will be accepted, thus making postmortem donors largely superfluous. Given these strong arguments against the use of postmortem collected sperm, a good alternative to enlarge the donor pool would be men who stored sperm for self-use and no (...) longer have the intention to use it. (shrink)

We have discovered that a single sperm protein, phospholipase C‐zeta (PLCζ), can stimulate intracellular Ca2+ signalling in the unfertilized oocyte (‘egg’) culminating in the initiation of embryonic development. Upon fertilization by a spermatozoon, the earliest observed signalling event in the dormant egg is a large, transient increase in free Ca2+ concentration. The fertilized egg responds to the intracellular Ca2+ rise by completing meiosis. In mammalian eggs, the Ca2+ signal is delivered as a train of long‐lasting cytoplasmic Ca2+ oscillations that (...) begin soon after gamete fusion and persist beyond the completion of meiosis. Sperm PLCζ effects Ca2+ release from egg intracellular stores by hydrolyzing the membrane lipid PIP2 and consequent stimulation of the inositol 1,4,5‐trisphosphate (InsP3) receptor Ca2+‐signalling pathway, leading to egg activation and early embryogenesis. Recent advances have refined our understanding of how PLCζ induces Ca2+ oscillations in the egg and also suggest its potential dysfunction as a cause of male infertility. (shrink)

In several publications Graeme Forbes has developed and defended one of the strongest arguments for essentialism about biological origins. I attempt to show that there are deep, as yet unrecognized, problems with this argument. The problems with Forbes’s argument suggest that a range of other arguments for various forms of origin essentialism are also likely to be flawed, and that we should abandon the seemingly plausible general metaphysical thesis that concrete entities that share all intrinsic properties are identical.

Results of genetic analyses show that social groups of female and immature sperm whales are comprised of multiple matrilines as evidenced by the presence of multiple mitochondrial (maternally inherited) control region haplotypes. These data suggest: (1) a social environment in which the transmission of cultural information, such as vocal dialects, is more likely to be horizontal or oblique rather than strictly vertical (mother-offspring) and (2) lead us to question the data presented to support gene-culture coevolution.