Concern mounts over female genital mutilation

According to estimates by the WHO, up to 140 million girls and women have undergone female genital mutilation (FGM), and each year another 2 million are thought to be at risk of it. Most girls who undergo this ritual live in Africa and to a lesser extent in Asia and the Middle East. However, there has been an increasing occurrence of genital mutilations among migrants from these countries who have settled in the US, Europe, and Australia. Although some countries prohibit the practice, evidence suggests that these laws are defied. In the UK, Baroness Ruth Rendell, the prime mover behind a cross-party parliament inquiry into FGM is convinced that some health professionals are still carrying out the operation on request. To this effect, she is advocating some prosecutions under the 1985 act. Rendell is also pressing for resources to be put into education and awareness campaigns for girls and women to have an informed choice as to whether to submit to the procedure or not.     

Female genital mutilation and monandry in an orb-web spider

Monandry, in which a female has only one mating partner during the reproductive period, is established when a female spontaneously refrains from re-mating, or when a partner male interferes with the attempts of a female to mate again. In the latter case, however, females often have countermeasures against males, which may explain why polyandry is ubiquitous. Here, I demonstrate that the genital appendage, or scape, of the female orb-web spider (Cyclosa argenteoalba) is injured after her first mating, possibly by her first male partner. This female genital mutilation (FGM) permanently precludes copulation, and females appear to have no countermeasures. FGM is considered to confer a strong advantage to males in sexual conflicts over the number of female matings, and it may widely occur in spiders.     

Male genital mutilation: an adaptation to sexual conflict

Male genital mutilation (MGM) takes several forms and occurs in about 25% of societies. This behavior has puzzled anthropologists, doctors and theologians for centuries, and presents an evolutionary challenge since it involves dangerous and costly surgery. I suggest that MGM is likely to reduce insemination efficiency, reducing a man's capacity for extra-pair fertilizations by impairing sperm competition. MGM may therefore represent a hard-to-fake signal of a man's reduced ability to challenge the paternity of older men who are already married. Men who display this signal of sexual obedience may gain social benefits if married men are selected to offer social trust and investment preferentially to peers who are less threatening to their paternity. Clitoridectomy and vaginal infibulation serve a parallel signaling function in women, increasing a husband's paternity certainty and garnering his increased investment. Especially in societies where paternity uncertainty and reproductive conflict are high, the social benefits of MGM as a signal may outweigh its costs. This ‘sexual conflict’ hypothesis predicts that MGM should be associated with polygyny, particularly when co-wives reside far apart, and that MGM should reduce the frequency of extramarital sex. MGM rituals should facilitate access to social benefits; they should be highly public, watched mainly by men, and performed by a nonrelative. I found support for these six predictions in two cross-cultural samples. I also examined an alternative hypothesis suggesting that MGM signals group commitment for collective action, particularly inter-societal warfare. Although other forms of male scarification fit this model, the distribution of MGM is not predicted by frequency of inter-societal warfare.     

Female genital mutilation and cosmetic surgery: regulating non-therapeutic body modification

In the UK, female genital mutilation is unlawful, not only when performed on minors, but also when performed on adult women. The aim of our paper is to examine several arguments which have been advanced in support of this ban and to assess whether they are sufficient to justify banning female genital mutilation for competent, consenting women. We proceed by comparing female genital mutilation, which is banned, with cosmetic surgery, towards which the law has taken a very permissive stance. We then examine the main arguments for the prohibition of the former, assessing in each case both (a) whether the argument succeeds in justifying the ban and, if so, (b) whether a parallel argument would not also support a ban on the latter. We focus on the following arguments. Female genital mutilation should be unlawful because: (1) no woman could validly consent to it; (2) it is an oppressive and sexist practice; (3) it involves the intentional infliction of injury; (4) it causes offence. Our view is that arguments (3) and (4) are unsound and that, although arguments (1) and (2) may be sound, they support not only a ban on female genital mutilation, but also one on (some types of) cosmetic surgery. Hence, we conclude that the present legal situation in the UK is ethically unsustainable in one of the following ways. Either the ban on female genital mutilation is unjustified because arguments (1) and (2) are not in fact successful; or the law's permissive attitude towards cosmetic surgery is unjustified because arguments (1) and (2) are in fact successful and apply equally to female genital mutilation and (certain forms of) cosmetic surgery. The people of the countries where female genital mutilation is practised resent references to 'barbaric practices imposed on women by male-dominated primitive societies', especially when they look at the Western world and see women undergoing their own feminization rites intended to increase sexual desirability: medically dangerous forms of cosmetic plastic surgery, for instance....     

Mate plugging via genital mutilation in nephilid spiders: an evolutionary hypothesis

Nephilid spiders are known for gigantic females and tiny males. Such extreme sexual dimorphism and male-biased sex ratios result in fierce male–male competition for mates. Intense sperm competition may be responsible for behaviors such as mate guarding, mate binding, opportunistic mating, genital mutilation, mating plugs and male castration (eunuchs). We studied the mating biology of two phylogenetically, behaviorally and morphologically distinct south-east Asian nephilid spider species ( Herennia multipuncta, Nephila pilipes ) in nature and in the laboratory. Specifically, we established the frequencies and effectiveness of plugging (a plug is part of the male copulatory organ), and tested for male and female copulatory organ reuse. Both in nature and in the laboratory, plug frequencies were higher in H. multipuncta (75–80% females plugged) compared with N. pilipes (45–47.4%), but the differences were not significant. Plugs were single and effective (no remating) in H. multipuncta but multiple and ineffective (remating possible) in N. pilipes . In Herennia , the males plugged when the female was aggressive and in Nephila plugging was more likely when mating with previously mated and larger females. Further differences in sexual biology are complete palpal removal and higher sexual aggressiveness in Herennia (sexual cannibalism recorded for the first time), and mate binding in Nephila . Thus, we propose the following evolutionary hypothesis: nephilid plugging was ancestrally successful and enabled males to monopolize females, but plugging became ineffective in the phylogenetically derived Nephila . If the evolution of nephilid sexual mechanisms is driven by sexual conflict, then the male mechanism to monopolize females prevailed in a part of the phylogeny, but the female resistance to evade monopolization ultimately won the arms race.     

Repeated evolution of male sacrifice behavior in spiders correlated with genital mutilation

According to sexual cannibalism theory, male complicity in terminal mating can be adaptive when the male's future reproductive value is low relative to the benefits of self sacrifice. Spiders and insects that exhibit male sacrifice behavior (either complicity in cannibalism or spontaneous death associated with copulation) often also have male genitalia that stereotypically become broken or disfigured the first time they are used for copulation, potentially lowering his future reproductive value. Theoretical work on monogamy has identified male bias in the effective sex ratio as a precursor to the evolution of monogamy (including male sacrifice) as an adaptive form of paternity protection. Using phylogeny-based statistics and drawing on several phylogenetic studies of araneoid spiders, I investigate relationships between male sacrifice behavior, genital mutilation, extreme sexual size dimorphism, and the accumulation of multiple males in the female web (as an indicator of a male-based effective sex ratio). This investigation focuses on araneoid spiders because several independent origins of sacrifice behavior are known for this group and the phylogenetic structure of the lineage is relatively well studied. I report that male genital mutilation is significantly correlated with sacrifice behavior and argue that this finding is consistent with sexual cannibalism theory. Male sacrifice behavior is also correlated with male accumulation, a result that is consistent with theoretical work on the evolution of monogamy. Male accumulation and extreme sexual size dimorphism are correlated suggesting that sex-based differences in maturation time can lead to a male biased effective sex ratio. Similar patterns of correlated characters may hold for some insect taxa. Studying traits that have appeared independently in multiple lineages is a powerful method for developing general theories about the evolution of biological phenomena.     

Copulatory mechanism in a sexually cannibalistic spider with genital mutilation (Araneae: Araneidae: Argiope bruennichi)

Genitalia are among the fastest evolving morphological traits as evidenced by their common function as diagnostic traits in species identification. Even though the main function of genitalia is the successful transfer of spermatozoa, the presence of diverse structures that are obviously not necessary for this suggests that genitalia are a target of sexual selection. The male genitalia of many spider species are extremely complex and equipped with numerous sclerites, plates and spines whose functions are largely unknown. Selection on male genitalia may be particularly strong in sexually cannibalistic spiders, where mating success of males is restricted to a single female. We investigated the copulatory mechanism of the sexually cannibalistic orb weaving spider Argiope bruennichi by shock freezing mating pairs and revealed a complicated interaction between the appendices and sclerites that make up the male gonopods (paired pedipalps). The plate that covers the female genital opening (scape) is secured between two appendices of the male genital bulb, while three sclerites that bear the sperm duct are unfolded and extended into the female copulatory opening. During copulation, females attack and cannibalise the male and males mutilate their genitalia in about 80% of cases. Our study demonstrates that (i) genital coupling is largely accomplished on the external part of the female genitalia, (ii) that the mechanism requires an interaction between several non-sperm-transferring structures and (iii) that there are two predetermined breaking points in the male genitalia. Further comparative work on the genus Argiope will test if the copulatory mechanism with genital mutilation indeed is an adaptation to sexual cannibalism or if cannibalism is a female counter adaptation to male monopolisation through genital plugging.     

Securing paternity in spiders? A review on occurrence and effects of mating plugs and male genital mutilation

Low female mating frequencies often appear to be cases of direct male induction that can oppose female interests. Mating plugs are most obvious means leading to low degrees of multiple mating in females. In spiders, mating plugs are formed by a variety of amorphous materials, by the breakage of the male sperm transferring organ, or by the whole male that functions as a mating barrier. Our compilation of the available information on the presence of the various types of mating plugs suggests that plugs predominantly occur in entelegyne spiders. In this group, plugs do not interfere with oviposition since separate openings for insemination and oviposition are present. In contrast, mating plugs seem to be rare in haplogyne spiders that do not possess separate openings. The available experimental studies on the function of the different types of plugs suggest that plugs can be considered as male adaptations to avoid sperm competition. However, females in some cases were shown to have evolved means to prevent or control male manipulation or may selectively favour plug production in specific males, an aspect which has largely been neglected. In order to understand plug evolution and function we need to explore the morphological, behavioural and biochemical aspects involved and extend our approach to interactions between the sexes.     

Dental mutilation and associated abnormalities in Uganda

In 1966 during a dental survey of four districts in Uganda — Acholi in the north, Bugisu in the east, and Kigezi and Toro in the southwest — 1169 Africans were examined. In the sample from Kigezi District 11.9% of the Bakiga tribe showed a form of dental mutilation consisting of the filing away of the mesial angle of the upper central incisors. In the sample from Acholi District 16.1% of the Acholi tribe showed abnormal conditions related to the ritual extraction of the primary canines. Extraction of the lower permanent incisors was seen occasionally in the Acholis (8), Batoros (1) and Bugisus (3). Removal of the primary canines is attributed to a belief that infantile fever originates from these teeth. Because the primary canines were removed in a crude fashion, malformation, non-eruption or premature eruption of the underlying permanent canines resulted.     

The African custom of tooth mutilation in America

A broad historical sketch of tooth mutilation stresses the role of Negro slaves in introducing the African custom into America, and the possibility of filling in gaps in our knowledge along this line from recovered skeletal remains. As an example of what can be learned, a skeleton found recently in Grenada, West Indies, is described as that of a male Negro, with a West African type of dental mutilation. The individual represented is shown to have been around 35–40 years of age, below average in size, with bandy legs, signs of mild deficency disease, and a variety of dental and periodontal diseases. Geographical and historical factors are reviewed in an effort to decide whether or not he was one of the original slaves or a descendant of a slave. The authors conclude that the circumstances of the find warrant the belief that he had been born in Africa and received his mutilation there. An earlier report of another such find in Barbados, and the mention of a subsequent find in St. Croix, suggest that a more intensive search for Negro remains in the West Indies would prove fruitful.