Epidemiological transitions, reproductive health, and the Flexible Response Model

In concert with improving standards of living since the mid-19th century, chronic and non-infectious diseases replaced infectious diseases as the major causes of mortality in more developed countries. Thus, economic development has been seen as one strategy to improve women's reproductive health. However, rates of two of the major contributors to women's illness, maternal mortality and breast cancer, do not correspond well with the level of economic development. Drawing upon our longitudinal study of reproductive functioning among rural Bolivians (Project Reproduction and Ecology in Provincia Aroma (REPA)), we propose an evolutionary model to explain variation in certain aspects of women's reproductive health. Our findings suggest new avenues of inquiry into the determinants of reproductive health and have implications for improving the well-being of women worldwide.     

Evidence of genetic monogamy in the lemur Indri (Indri indri)

Monogamy is a rare strategy among mammals but relatively common among primates. The study of the evolution of monogamy in mammals and primates is lacking empirical studies that assess the relationship between a pair‐living social organization and genetic monogamy. Sexual or genetic monogamy can only be assessed by performing molecular analyses and investigating rates of extra‐pair paternity (EPP). Studying the occurrence of EPP can provide valuable insights into reproductive strategies and their adaptive value. The indri is a pair‐living primate that lives in stable groups. Their social units are composed of the reproductive pair and up to four more individuals, but extra‐pair copulation (EPC) can occur. This raises the question of whether this event may or may not lead to EPP. Here, we investigated whether a pair‐living social organization corresponds to genetic monogamy in indris (Indri indri). We analyzed the paternity of 12 offspring from seven pairs using a set of six microsatellite loci on fecal samples (mean number of alleles 11.7 ± 1.8 (mean ± standard deviation). We found that in 92% of cases the genetic profile of the offspring matched the paired male of the group for all the loci considered. In the only case of paternity mismatch, the paternity assignment remained inconclusive. Our results show that I. indri genetic monogamy is the norm and supports the hypothesis that pair‐living social organization is associated with low EPP rate. Also, our results are in contrast with the hypothesis of infertility as a reason to engage in EPC for this species.     

Extra-pair paternity and egg dumping in birds: life history,parental care and the risk of retaliation

Molecular techniques have revealed striking variation among bird species in the rates of extra-pair paternity (EPP) and intraspecific brood parasitism (IBP). In terms of the proportion of broods affected, rates of EPP and IBP vary across species from 0-95% and 0-50%, respectively. Despite a plethora of hypotheses and several careful comparative analyses, few robust correlates of this interspecific variation have been identified. One explanation for this shortfall is that most comparative studies have tended to focus on contemporary ecological factors and ignored fundamental differences in reproductive biology that evolved millions of years ago. We show that, for both EPP and IBP, over 50% of interspecific variation is due to differences among taxonomic families and orders. Therefore, we test hypotheses that predict interspecific variation in the rate of alternative reproductive strategies should be associated with differences in life history and the form of parental care. Our analyses largely support these predictions, with high rates of reproductive cheating being associated with 'fast' life histories. High EPP rates are associated with high rates of adult mortality and reduced paternal care. High IBP rates are associated with high-fecundity rates. These patterns remain intact whether we use species as independent data points or evolutionary contrasts based on either molecular or morphological phylogenies. These results are interpreted as supporting the idea that alternative reproductive strategies are most common in taxa in which the risks of retaliation are low. We suggest a hierarchical explanation for interspecific variation in the incidence of alternative reproductive strategies. Variation between major avian lineages in the EPP and IBP rates are determined by fundamental differences in life history and parental care that evolved many millions of years ago. Variation between populations or individuals of the same species, however, are more likely to be determined by differences in contemporary ecological and genetic factors.     

The hide-and-seek game: men's perspectives on abortion and contraceptive use within marriage in a rural community in Zimbabwe

This paper is based on a study aimed at understanding the perceptions of men to induced abortion and contraceptive use within marriage in rural Zimbabwe. Two qualitative methods were combined. Men were found to view abortion not as a reproductive health problem for women. Instead, they described abortion as a sign of illicit sexual activity and contraceptive use as a strategy married women use to conceal their involvement in extramarital sexual activity. Men felt anxious and vulnerable for lack of control over women. In the absence of verbal communication on sexual matters, women and men resort to what are called here 'hide-and-seek' strategies, where women acquire and use contraceptives secretly while men search for evidence of such use. It is concluded that promoting women's sexual and reproductive health requires both short- and long-term strategies. The short-term strategy would entail providing women with reproductive technology they can use without risking violence. The long-term strategy would entail understanding men's concerns and the way these are manifested. In turn this requires the use of methodologies that encourage dialogue with research participants, in order to capture their deep meanings and experiences.     

Age‐dependent changes in infidelity in Seychelles warblers

Extra‐pair paternity (EPP) is often linked to male age in socially monogamous vertebrates; that is, older males are more likely to gain EPP and less likely to be cuckolded. However, whether this occurs because males improve at gaining paternity as they grow older, or because “higher quality” males that live longer are preferred by females, has rarely been tested, despite being central to our understanding of the evolutionary drivers of female infidelity. Moreover, how extra‐pair reproduction changes with age within females has received even less attention. Using 18 years of longitudinal data from an individually marked population of Seychelles warblers (Acrocephalus sechellensis), we found considerable within‐individual changes in extra‐pair reproduction in both sexes: an early‐life increase and a late‐life decline. Furthermore, males were cuckolded less as they aged. Our results indicate that in this species age‐related patterns of extra‐pair reproduction are determined by within‐individual changes with age, rather than differences among individuals in longevity. These results challenge the hypothesis—based on longevity reflecting intrinsic quality—that the association between male age and EPP is due to females seeking high‐quality paternal genes for offspring. Importantly, EPP accounted for up to half of male reproductive success, emphasizing the male fitness benefits of this reproductive strategy. Finally, the occurrence of post‐peak declines in extra‐pair reproduction provides explicit evidence of senescence in infidelity in both males and females.     

Extra-pair paternity in the strongly monogamous Wandering Albatross Diomedea exulans has no apparent benefits for females

Although 92% of avian species are socially monogamous, extra-pair copulation (EPC), resulting in extra-pair paternity (EPP), is a common reproductive strategy in birds. Among seabirds, in which the rate of social monogamy reaches 100%, Procellariiformes (albatrosses and petrels) show low EPP rates, with the noticeable exception of the only albatross investigated in this regard, the Waved Albatross Phoebastria irrorata . This species, in which forced copulations are known to occur, showed a surprisingly high rate of EPP (25% of chicks). We investigate here EPP rates in another albatross species, the Wandering Albatross Diomedea exulans , subject to a demographic survey conducted for 38 years. We combined data on pair bonds with analysis of ten microsatellite loci and found that 10.7% of 75 chicks had an extra-pair sire. Although there was some evidence for inbreeding avoidance, within-pair and extra-pair chicks showed similar levels of heterozygosity, and the incidence of EPP was independent of age, experience or past reproductive success. Hence, we found no evidence that females benefit from EPCs. Owing to the male-biased sex ratio in adults, widowed and divorced males required more time to find a new mate (+28 and +72%, respectively) than did females. Combined with high sexual size dimorphism, this phenomenon might promote the forced copulations observed in this species. Our data therefore suggest that EPC is beneficial to unpaired males but occurs at random in females, consistent with the hypothesis that EPP results solely from forced EPCs. However, the importance of the latter for EPP and the part played by solitary males require further investigation.     

Parental age difference, educationally assortative mating and offspring count: evidence from a contemporary population in Taiwan

Using contemporary population data from Taiwan, we examine the relationships between parental age difference, educationally assortative mating, income and offspring count. Controlling for women's reproductive value (measured by age at first birth), we find that an older husband is associated with fewer offspring, whereas a husband with similar or higher education is associated with more offspring. Concerning resources, we find that women's income is negatively associated with fertility and husband's income is positively associated with fertility among highly educated women. These results are consistent with the view that women compensate for trade-offs between education, income generation and childbearing by seeking mates with a higher status.     

Low historical rates of cuckoldry in a Western European human population traced by Y-chromosome and genealogical data

Recent evidence suggests that seeking out extra-pair paternity (EPP) can be a viable alternative reproductive strategy for both males and females in many pair-bonded species, including humans. Accurate data on EPP rates in humans, however, are scant and mostly restricted to extant populations. Here, we provide the first large-scale, unbiased genetic study of historical EPP rates in a Western European human population based on combining Y-chromosomal data to infer genetic patrilineages with genealogical and surname data, which reflect known historical presumed paternity. Using two independent methods, we estimate that over the last few centuries, EPP rates in Flanders (Belgium) were only around 1–2% per generation. This figure is substantially lower than the 8–30% per generation reported in some behavioural studies on historical EPP rates, but comparable with the rates reported by other genetic studies of contemporary Western European populations. These results suggest that human EPP rates have not changed substantially during the last 400 years in Flanders and imply that legal genealogies rarely differ from the biological ones. This result has significant implications for a diverse set of fields, including human population genetics, historical demography, forensic science and human sociobiology.     

High fidelity: extra‐pair fertilisations in eight Charadrius plover species are not associated with parental relatedness or social mating system

Extra‐pair paternity is a common reproductive strategy in many bird species. However, it remains unclear why extra‐pair paternity occurs and why it varies among species and populations. Plovers (Charadrius spp.) exhibit considerable variation in reproductive behaviour and ecology, making them excellent models to investigate the evolution of social and genetic mating systems. We investigated inter‐ and intra‐specific patterns of extra‐pair parentage and evaluated three major hypotheses explaining extra‐pair paternity using a comparative approach based on the microsatellite genotypes of 2049 individuals from 510 plover families sampled from twelve populations that constituted eight species. Extra‐pair paternity rates were very low (0 to 4.1% of chicks per population). No evidence was found in support of the sexual conflict or genetic compatibility hypotheses, and there was no seasonal pattern of extra‐pair paternity (EPP). The low prevalence of EPP is consistent with a number of alternative hypotheses, including the parental investment hypothesis, which suggests that high contribution to care by males restricts female plovers from engaging in extra‐pair copulations. Further studies are needed to critically test the importance of this hypothesis for mate choice in plovers.     

Little effect of extrapair paternity on the opportunity for sexual selection in Savannah sparrows (Passerculus sandwichensis)

Extrapair paternity (EPP) can dramatically increase the opportunity for sexual selection if relatively few males are able to monopolize the majority of fertilizations in a population. Although recent work with birds suggests that EPP can increase the standardized variance in male reproductive success (Is) as much as 13-fold, only a male's within-pair success is typically quantified with any accuracy. In most cases, nearly half of all extrapair young are of unknown parentage. A strong, negative correlation across studies between the proportion of extrapair young for which parentage is known and the apparent effect of EPP on Is (r(s) = -0.71, P = 0.013, N = 13 studies) suggests that the incomplete sampling of extrapair sires has greatly exaggerated the influence of EPP. To achieve a more thorough accounting of EPP and its importance to variation in male fitness, we used a suite of four to six microsatellite loci to identify extrapair young and their sires in a polygynous population of Savannah sparrows (Passerculus sandwichensis). Pooling over the 2002 and 2003 breeding seasons, 79 of 116 females (68.1%) produced young outside of the pairbond and 194 of 411 offspring (47.2%) were extrapair. We identified sires for 96.4% of all young (N = 396), including sires for 92.3% of the extrapair young (N = 179), allowing us to partition Is into within-pair and extrapair components. In both years, EPP-related fitness components generated more variation in male reproductive success than the number or quality of within-pair mates. Differences among males in the number of extrapair mates alone accounted for 56.6% of Is in 2002 and for 23.6% of Is in 2003. Nonetheless, in absolute terms, the occurrence of EPP on Kent Island increased the opportunity for sexual selection less than two-fold. Averaging over the two years, Is was only 78% higher than Is,app, the variance in male reproductive success that would have occurred had EPP been nonexistent and males sired all young on their territories. Likewise, across nine socially monogamous species, we found no correlation between the extent of EPP and its effect on the opportunity for sexual selection (Is/Is,app) and only a marginally significant positive correlation between EPP and Is itself. Taken together, our results suggest that the relationship between EPP and sexual selection in birds may be much less strong and much less straightforward than commonly thought.     

Invoking vali: painful technologies of modern birth in south India

As reproduction becomes increasingly biomedicalized throughout the globe, reproductive technologies are used in unique ways and imbued with different meanings. This article explores why lower-class women in south India in the 1990s were demanding to have childbirth labors induced with oxytocin drugs while rejecting anesthesia. Cultural constructions of women's reproductive power are evoked and reworked in discourses of modernity that explain this preference. Discourses on relationships among gender, pain, and modernity relate to political-economic constraints on hospitals to perpetuate this practice.     

Women's status and infant mortality in rural Colombia

This paper investigates the effects of maternal demographic characteristics and social and economic statuses on infant mortality in rural Colombia. Demographic characteristics include the age of the mother, parity and length of preceding interbirth interval, and sex of infant. Measures of women's status at the time of birth include education, wage labor and occupation, economic stratum, place of residence, and whether the mother is living with a husband. The life history data for the study (involving 4,928 births) were collected in 1986 from a representative sample of two cohorts of women resident in rural central Colombia. Overall differentials in infant mortality by measures of women's status are small and are in good part associated with the differing reproductive behaviors of the women and variations in breastfeeding practices. The sharp declines in infant mortality recorded in rural Colombia in recent years appear less related to improved status of women than to reductions in fertility that enhance infant survivorship and to public health interventions shared by all segments of the population.     

EGG FREEZING: A BREAKTHROUGH FOR REPRODUCTIVE AUTONOMY?

This article describes the relatively new technology of freezing human eggs and examines whether egg freezing, specifically when it is used by healthy women as 'insurance' against age-related infertility, is a legitimate exercise of reproductive autonomy. Although egg freezing has the potential to expand women's reproductive options and thus may represent a breakthrough for reproductive autonomy, I argue that without adequate information about likely outcomes and risks, women may be choosing to freeze their eggs in a commercially exploitative context, thus undermining rather than expanding reproductive autonomy.     

Situating Women's Reproductive Activities

In her pathbreaking book, Abortion and Woman's Choice, Rosalind Pollack Petchesky astutely observed that, in many societies, control over the methods and goals of reproduction is a critical site of contest, particularly between women and men. Yet the circumstances under which reproductive relations will be characterized by conflict, consensus, or some of both have seldom been systematically explored. In this paper, I therefore offer three examples of different structural contexts in which either women or men had the preponderance of power to influence key aspects of women's reproductive activities. I argue that while structural factors, notably the distribution of economic, political, and institutional resources, are fundamental, they do not only act directly but are experienced, interpreted, and made meaningful through specific cultural processes, particularly gender ideologies, norms about morality, and beliefs about how women should behave. It is together that these structural factors and cultural processes shape the climates and contexts within which women's reproductive activities are situated and take place, [reproduction, gender politics, Latin America, Mexican Americans]     

Does nest predation risk affect the frequency of extra‐pair paternity in a socially monogamous passerine?

While considerable variations in both the frequency of extra‐pair paternity (EPP) and the behavioral events that produce it are recognized among species, populations, individuals, and breeding attempts, the determinants of these variations are surprisingly difficult to establish. Nest predation may be one such determinant, since it is the most important source of reproductive failure, and past studies have suggested a variety of reproductive flexibilities under nest predation risk. However, despite its potentially significant effect on mating behaviors, nest predation risk has rarely been discussed in association with variations in intraspecific EPP patterns. Here, we examined the effect of naturally occurring nest predation, which varied between sites, years, and breeding attempts, on patterns of EPP in 92 broods (132 adults and 710 nestlings) of the Japanese great tit Parus major minor. We found that the frequency of extra‐pair offspring was positively correlated with the nest predation rate, along with a correlation to breeding attempts in a season, but not with other factors such as individual quality or breeding density. Under high nest‐predation risk, it may be adaptive for males to search for additional extra‐pair copulation to spread the risk of losing all offspring and to invest less in mate‐guarding, which also enables females to seek additional extra‐mating. The results of this study suggest that nest predation risk, among other factors, may significantly influence paternity allocation in birds.     

A model of fertility motivation, desires, and expectations early in women's reproductive careers

We propose a general model of the relationships connecting fertility motivations, desires, and expectations in which motivations are antecedent to desires, which in turn are antecedent to expectations. We describe differences in the model as it applies to women early in their reproductive careers, specifically, after marriage but before their 1st birth and after their 1st birth but before their 2nd. We test the model with data from 311 just-married and 318 just-mothered US women enrolled in a prospective psychology of reproduction study, using LISREL (analysis of linear structural relationships by the method of maximum likelihood) software to estimate structural equations for both groups. The general model fits the data well. There are 3 primary differences in the model with respect to the 2 groups of married women. How soon a woman expects her next child affects how many children she expects only among the just-married woman. The number of children expected by the woman is the only antecedent to how soon she expects her next child among the just-mothered women. Both positive and negative maternal motivation has effects among the just-married women, but only negative maternal motivation has effects among the just-mothered women. These and other differences are discussed in terms of psychological and situational developments occurring early in women's reproductive careers.     

IVF and women's interests: an analysis of feminist concerns

Feminist objections to the new reproductive technologies are examined. The author argues that although these technologies entail significant risks and costs to women, help only a small minority, and do not address the underlying social causes of infertility, women's interests do not demand the rejection of research on and use of reproductive technologies. Their potential threat to female reproductive autonomy can be counteracted by protecting individual civil rights. Warren urges that women, as well as members of various racial, ethnic, and socioeconomic groups, be represented in decisions on reproductive technologies, participate in their development and funding, and supervise their provision.     

How female reed buntings benefit from extra-pair mating behaviour: testing hypotheses through patterns of paternity in sequential broods

Extra-pair paternity is an important aspect of reproductive strategies in many species of birds. Given that in most species females control whether fertilization occurs, they are expected to benefit in some way from the extra-pair matings. In this study we use patterns of extra-pair paternity (EPP) in broods of individual reed buntings (Emberiza schoeniclus), both within and between seasons, to test four hypothesized female benefits: (1) assessing potential future partners and seeking (2) genetic diversity (3) good genes, or (4) compatible genes. Reed buntings are socially monogamous, multibrooded passerines with extremely high levels of extra-pair paternity. We studied a population of reed buntings in the Netherlands in 2002 and 2003; 51% of offspring in 74% of nests were extra-pair. We showed that patterns of EPP did not support the first and second hypotheses, since females did not form a pair with previous extra-pair partners, EPP was not evenly distributed among broods and more broods than expected were sired by a single male. Furthermore, there was no relation between a male's within- and extra-pair fertilization success, no consistency in EPP between breeding attempts, no effect of parental relatedness on EPP and several cases of reciprocal paternity. These patterns do not support the good genes hypothesis and are most consistent with the genetic compatibility hypothesis. However, our previous finding that older males are more successful in gaining EPP, suggests some effect of good genes. These hypotheses need not be mutually exclusive, as females may select compatible males above a certain quality threshold (e.g. old males).     

Promiscuity drives sexual selection in a socially monogamous bird

Many socially monogamous species paradoxically show signs of strong sexual selection, suggesting cryptic sources of sexual competition among males. Darwin argued that sexual selection could operate in monogamous systems if breeding sex ratios are biased or if some males attract highly fecund females. Alternatively, sexual selection might result from promiscuous copulations outside the pair bond, although several recent studies have cast doubt on this possibility, in particular by showing that variance in apparent male reproductive success (number of social young) differs little from variance in actual male reproductive success (number of young sired). Our results from a long-term study of the socially monogamous splendid fairy-wren (Malurus splendens) demonstrate that such comparisons are misleading and do not adequately assess the effects of extra-pair paternity (EPP). By partitioning the opportunity for selection and calculating Bateman gradients, we show that EPP has a strong effect on male annual and lifetime fitness, whereas other proposed mechanisms of sexual selection do not. Thus, EPP drives sexual selection in this, and possibly other, socially monogamous species.     

Vagina dentata revisited: Gender and asymptomatic shedding of genital herpes

Medical research on genital herpes indicates that women shed herpes asymptomatically. This paper examines the medical understanding of asymptomatic shedding of herpes among women as partial knowledge, meaning biased and incomplete, based upon folk models of male and female sexual bodies and upon the structure of medical practice. The focus on women's sexual anatomy as dangerous to men and the lack of a medical specialty on male reproductive/sexual health results in blaming women for transmission of sexual diseases.