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Este trabajo pretende poner de manifiesto que el principio monogámico es característico del matrimonio romano. Desde este contexto, comprender e integrar los principios de las estructuras conyugales del Derecho Romano y seguir su iter histórico-jurídico es esencial a fin de fortalecer el principio monogámico que informa el actual sistema, puesto que dicho principio ofrece las bases tanto de la estructura familiar privada, como de la ordenación y la gestión de lo público en los denominados Estados Sociales y Democráticos de Derecho. This paper aims to show that the monogamous principle is characteristic of Roman marriage. In this context, understanding and integrating the principles of theconjugal structures of Roman law and following its historical-legal iter is essential in order to strengthen the monogamous principle that informs the current system, since this principle provides the basis for both the private family structure and the organisation and management of public affairs in the so-called social and democratic states governed by the rule of law.

Evidence of an association between cooperative breeding systems and average coefficients of relatedness between group members in vertebrates have led to increased interest in the social and ecological factors affecting average kinship within groups. Previous studies have suggested that polygynous mating systems and high degrees of male reproductive skew increase average relatedness because they increase the proportion of offspring born in each group that are paternal siblings. Although this may be the case in semelparous organisms, in many multiparous polygynous animals, intense competition between males shortens the breeding tenure of males and leads to their frequent replacement by competitors which reduces paternal relatedness and average kinship between members of multigenerational groups. Here, we explore the interaction between male reproductive skew and the frequency of turnover in breeding males and its effects on within-group relatedness. Our theoretical model shows that increases in rates of dominance turnover in polygynous systems can offset the positive effect of male skew on relatedness between group members within seasons, showing that polygynous mating systems will not necessarily lead to significant increases in average relatedness, especially in species where there is extensive overlap between generations among group members.

In mammals, the dominant theory postulates a causal link between three sexual characters: first, sexual selection promoted the evolution of polygyny; then sexual size dimorphism (SSD) evolved due to male competition for mates in a polygynous context, finally sexual segregation occurred as a consequence of the different requirements generated by size difference between sexes. I reviewed the literature on artiodactyls to test an alternative hypothesis that SSD evolved by natural selection as a result of niche separation between sexes, which implies the reversal of the causal evolutionary relationships. I used phylogenetic confirmatory path analysis to test models that differ in the evolutionary links between characters and in the selection process (ecological pressures or competition for mates) involved. Path analysis indicated that the trigger for the evolutionary pathway toward polygyny was a shift from close to open habitats, which in turn caused an increase in body size, an increase in gregariousness, and dietary specialization. The subsequent transition was to a polygynous mating system, after which sexual segregation evolved, and SSD evolved mostly after niche separation between males and females. This alternative causal link ‘polygyny → sexual segregation → SSD’ can help to understand diverse phenomena, such as the ecological drivers of sexual segregation, the existence of many artiodactyl families that are monomorphic and polygynous and the correlated evolution of oral morphology.

Kin selection plays a major role in the evolution of cooperative systems. However, many social species exhibit complex within-group relatedness structures, where kin selection alone cannot explain the occurrence of cooperative behaviour. Understanding such social structures is crucial to elucidate the evolution and maintenance of multi-layered cooperative societies. In lamprologine cichlids, intragroup relatedness seems to correlate positively with reproductive skew, suggesting that in this clade dominants tend to provide reproductive concessions to unrelated subordinates to secure their participation in brood care. We investigate how patterns of within-group relatedness covary with direct and indirect fitness benefits of cooperation in a highly social vertebrate, the cooperatively breeding, polygynous lamprologine cichlid Neolamprologus savoryi. Behavioural and genetic data from 43 groups containing 578 individuals show that groups are socially and genetically structured into subgroups. About 17% of group members were unrelated immigrants, and average relatedness between breeders and brood care helpers declined with helper age due to group membership dynamics. Hence the relative importance of direct and indirect fitness benefits of cooperation depends on helper age. Our findings highlight how both direct and indirect fitness benefits of cooperation and group membership can select for cooperative behaviour in societies comprising complex social and relatedness structures. This article is protected by copyright. All rights reserved.

Biological invasions are becoming more prevalent due to the rise of global trade and expansion of urban areas. Ants are among the most prolific invaders, with many exhibiting a multi-queen colony structure, dependent colony foundation and reduced inter-nest aggression. Although these characteristics are generally associated with the invasions of exotic ants, they may also facilitate the spread of native ants into novel habitats. Native to diverse habitats across North America, the odorous house ant Tapinoma sessile has become abundant in urban environments throughout the United States. Natural colonies typically have a small workforce, inhabit a single nest, and are headed by a single queen, whereas urban colonies tend to be several orders of magnitude larger, inhabit multiple nests (i.e., polydomy) and are headed by multiple queens (i.e., polygyny). Here, we explore and compare the population genetic and breeding structure of T. sessile within and between urban and natural environments in several localities across its distribution range. We found the social structure of a colony to be a plastic trait in both habitats, although extreme polygyny was confined to urban habitats. Additionally, polydomous colonies were only present in urban habitats, suggesting T. sessile can only achieve supercoloniality within urbanized areas. Finally, we identified strong differentiation between urban and natural populations in each locality and continent-wide, indicating cities may restrict gene flow and exert intense selection pressure. Overall, our study highlights urbanization's influence in charting the evolutionary course for species.

Many social mammals form discrete social communities within larger populations. For nonterritorial, polygynous, size-dimorphic species, sex- and age-class differences in life-history requirements might mediate differences in social connectedness and transitions among communities. We conducted social network analysis and community detection with an extensive data set of 1081 individually identified wild giraffes, Giraffa camelopardalis, over 5 years to test predictions that adult males and young of both sexes show greater social connectedness (degree, closeness and betweenness centrality) and transition more often among social communities than adult females, which form stronger and more stable relationships. We also expected that young animals would be more socially connected than adults. Using both static and dynamic network clustering techniques, we detected four distinct mixed-sex social communities, which we termed ‘super-communities’ to differentiate this apex level of social organization from intermediate-level female-only communities. Most (∼70%) giraffes remained within their same super-community, and those (usually adult males) that visited a different super-community often returned to their original super-community. Males – both adults and calves – had higher social centrality scores than females, and adult males were closer to all other individuals in the network and transitioned among super-communities twice as often as females and calves, reflecting their roaming reproductive strategy of seeking females in oestrus. Of all age and sex classes, young males had the most social ties and highest betweenness (moved most often among groups), which we attributed to social exploration prior to natal dispersal. Overall, female giraffes have stronger social associations than males, but males exceed females in measures of social connectedness, reflecting differences in reproductive and life-history profiles. Our findings suggest that giraffe translocations that do not consider sociality are likely to break up established social associations and potentially reduce fitness.

This repository contains the data and the supplementary materials for the manuscript "Offspring sex ratio increases with male reproductive success in the polygynous southern elephant seals". Description of the data is provided in the file "readme.txt"

This article revisits the issue of polygyny in Islam and the conditions men must meet before considered acceptable. Justified by the third verse of Sūrat al-Nisāʾ, participating in up to four conte...

Trade-offs between reproductive effort and subsequent growth in males are not well explored, despite their relevance in questions of individual energy allocation. Regarding the growth of sexual secondary characters in polygynous breeding male mammals, indeed, no conclusive studies exist. We investigated in male Alpine ibex (Capra ibex) the relationship between their behavioral reproductive effort, current horn size, and subsequent horn growth. While controlling for age, no evidence was found for male behavioral reproductive effort during the rut being affected by their horn size. On the other hand, reproductive effort significantly decreased age-specific horn growth during the following summer. Our study provides evidence that growth of secondary sexual characters is traded against behavioral investments in reproduction in a male mammal. It bears important implications for the understanding of energy allocation between various life-history components and the evolutionary ecology of secondary sexual characters.

Mating systems and patterns of reproductive success in fishes play an important role in ecology and evolution. While information on the reproductive ecology of many anadromous salmonids (Oncorhynchus spp.) is well detailed, there is less information for nonanadromous species including the Yellowstone Cutthroat Trout (O. clarkii bouvieri), a subspecies of recreational angling importance and conservation concern. Using data from a parentage‐based tagging study, we described the genetic mating system of a migratory population of Yellowstone Cutthroat Trout, tested for evidence of sexual selection, and identified predictors of mating and reproductive success. The standardized variance in mating success (i.e., opportunity for sexual selection) was significantly greater for males relative to females, and while the relationship between mating success and reproductive success (i.e., Bateman gradient) was significantly positive for both sexes, a greater proportion of reproductive success was explained by mating success for males (r 2 = 0.80) than females (r 2 = 0.59). Overall, the population displayed a polygynandrous mating system, whereby both sexes experienced variation in mating success due to multiple mating, and sexual selection was variable across sexes. Tests for evidence of sexual selection indicated the interaction between mating success and total length best‐predicted relative reproductive success. We failed to detect a signal of inbreeding avoidance among breeding adults, but the group of parents that produced progeny were on average slightly less related than adults that did not produce progeny. Lastly, we estimated the effective number of breeders (N b) and effective population size (N e) and identified while N b was lower than N e, both are sufficiently high to suggest Yellowstone Cutthroat Trout in Burns Creek represent a genetically stable and diverse population., We collected genetic samples from over 1,500 adult Yellowstone Cutthroat Trout as they entered a spawning tributary and subsequently collected ~3,000 genetic samples from outmigrating juveniles from the same creek system. Using a combination of sibship analysis and parentage‐based tagging, we identified a polygynandrous mating system, whereby both sexes experienced variation in mating success due to multiple mating, and sexual selection was variable across sexes. These data have direct implications for ongoing management and conservation efforts.

The neotropical manakins (family Pipridae) provide a great opportunity for integrative studies of sexual selection as nearly all of the 51 species are lek-breeding, an extreme form of polygyny, and highly sexually dimorphic both in appearance and behavior. Male courtship displays are often elaborate and include auditory cues, both vocal and mechanical, as well as visual elements. In addition, the displays are often extremely rapid, highly acrobatic, and, in some species, multiple males perform coordinated displays that form the basis of long-term coalitions. Male manakins also exhibit unique neuroendocrine, physiological, and anatomical adaptations to support the performance of these complex displays and the maintenance of their intricate social systems. The Manakin Genomics Research Coordination Network (Manakin RCN, https://www.manakinsrcn.org) has brought together researchers (many in this symposium and this issue) from across disciplines to address the implications of sexual selection on evolution, ecology, behavior, and physiology in manakins. The objective of this paper is to present some of the most pertinent and integrative manakin research as well as introducing the papers presented in this issue. The results discussed at the manakin symposium, part of the 2021 Society for Integrative and Comparative Biology Conference, highlight the remarkable genomic, behavioral, and physiological adaptations as well as the evolutionary causes and consequences of strong sexual selection pressures that are evident in manakins.

Following the introduction of DNA fingerprinting in the 1980s, studies have repeatedly revealed mismatches between the mating system inferred from social behaviour and the mating system revealed through genetic relationships. In this study, we examined the occurrence of extragroup paternities (EGPs) in gelada monkeys at Guassa, Ethiopia and explored how EGPs may be acquired in this species, which is conventionally considered to have a single breeding male (‘leader’) per social group (‘unit’). We found that while leaders sired most offspring, a substantial proportion (17 of 88 offspring, 19%) were sired by extra-unit males. Offspring were more likely to be sired by extra-unit males when they were: (1) conceived in the 6 months following the start of peak rainfall (July–December) and (2) the first successful conception for a mother. Furthermore, eight of the 17 extra-unit paternities were directly or indirectly the result of a single infertile leader, indicating that infertility plays an important role in the occurrence of EGPs. Compiling published data revealed that the 19% EGP rate observed among Guassa geladas was also the median for polygynous nonhuman primates (range 0–57%, N = 5 populations), in contrast to geladas in the Simien Mountains, where EGPs are absent or rare. Thus, intraspecific variation in EGP rates in geladas encompasses much of the range described across polygynous primates more broadly. The Guassa gelada EGP rate was similar to the median rate reported for mammals. Primates generally had a lower median rate of EGPs, more similar to the median rate reported for birds. Understanding variation in EGP rates requires understanding the outcomes of competing interests of males and females within the same species, as well as how these features contribute to the evolution of social systems and influence variation in EGP rates at higher taxonomic levels.

Certain predominant forms of mating and parental care systems are assumed in several model species among birds, but the opportunistic and apparently infrequent variations of “family structures” may often remain hidden due to methodological limitations with regard to genetic or behavioral observations. One of the intensively studied model species, the collared flycatcher (Ficedula albicollis), is usually characterized by social monogamy with polyterritorial, facultative social polygyny, and frequent extrapair mating and extrapair paternity. During a brood‐size manipulation experiment, we observed two females and a male delivering food at an enlarged brood. A combination of breeding phenology data (egg laying and hatching date), behavioral data (feeding rates) from video recordings at 10 days of nestling age, and microsatellite genotyping for maternity and paternity suggests a situation of an unrelated female helping a pair in chick rearing. Such observations highlight the relevance of using traditional techniques and genetic analyses together to assess the parental roles within a population, which becomes more important where individuals may dynamically switch from their main and presupposed roles according to the actual environmental conditions., The general mating and parental care systems are deeply studied in many model species, but we have only little information on the rare alternative tactics occurring under unforeseen, stressful environmental conditions. In this paper, we took a report on a case of cooperative nestling rearing with alloparental care in the socially monogamous collared flycatcher. Using together breeding phenology, behavioral, and genetic data, we provide a possible explanation for the observed phenomenon.

This paper examines how mobile communication and mobile banking is used by women in rural western Kenya (Elgeyo Marakwet), a resource-constrained area where women must carefully monitor the flow of...

In long‐lived polygynous species, male reproductive success is often monopolized by a few mature dominant individuals. Young males are generally too small to be dominant and may employ alternative tactics; however, little is known about the determinants of reproductive success for young males. Understanding the causes and consequences of variability in early reproductive success may be crucial to assess the strength of sexual selection and possible long‐term trade‐offs among life‐history traits. Selective pressures driven by fluctuating environmental conditions may depend on age class. We evaluated the determinants of reproduction in male bighorn sheep (Ovis canadensis) aged 2–4 years using 30 years of individual‐level data. These young males cannot defend estrous ewes and use alternative mating tactics. We also investigated how the age of first detected reproduction was correlated to lifetime reproductive success and longevity. We found that reproductive success of males aged 3 years was positively correlated to body mass, to the proportion of males aged 2–4 years in the competitor pool, and to the number of females available per adult male. These results suggest that reproductive success depends on both competitive ability and population age–sex structure. None of these variables, however, had significant effects on the reproductive success of males aged 2 or 4 years. Known reproduction before the age of five increased lifetime reproductive success but decreased longevity, suggesting a long‐term survival cost of early reproduction. Our analyses reveal that both individual‐level phenotypic and population‐level demographic variables influence reproductive success by young males and provide a rare assessment of fitness trade‐offs in wild polygynous males., Little is known about the determinants of reproductive success for young polygynous male mammals, although the causes and consequences of variability in early reproductive success may be crucial to assess the strength of sexual selection and possible long‐term trade‐offs among life‐history traits. We evaluated the determinants of reproduction in male bighorn sheep (Ovis canadensis) aged 2–4 years using 30 years of individual‐level data and investigated how the age of first reproduction was correlated to lifetime reproductive success and longevity. Early reproductive success was influenced by phenotypical and demographical variables, and males that first reproduced at early ages had higher lifetime reproductive success and shorter lifespan, suggesting a long‐term survival cost of early reproduction.

The genetic diversity of populations is the basis for individual fitness and potential adaptability to environmental changes. The South American fur seal (Arctocephalus australis) is a pinniped species that is widely distributed along the southern cone of South America. However, two distinct populations have evolved: the Northern Pacific/Peruvian population and the Southern Pacific/Atlantic population. One of the main breeding colonies of the Southern Pacific/Atlantic population is located on Guafo Island, in southern Chilean Patagonia. This breeding colony represents the closest reproductive population to the remote Peruvian group. Therefore, our study aimed to determine whether the Guafo colony may potentially facilitate gene flow, contribute new alleles, and increase genetic variability of the Peruvian populations, thereby linking the Northern and Southern Pacific populations for the species. In this study, species‐specific microsatellite markers were developed to genetically characterize Guafo Island's South American fur seal population. Our results confirm that the Guafo colony is a panmictic population with evidence of lack of genetic structure. Further, our results indicate that most individuals are unrelated and that half‐siblings are rare, suggesting that polygyny in this species is less frequent than previously thought. Finally, based on the identification of multiple pairs of full siblings, we also present the first genetic evidence of twins in South American fur seals. These attributes suggest that the Guafo colony is a large, panmictic population, which could act as a potential genetic reservoir, and ultimately assist in linking two genetically distinct populations.

[Background]: In polygynous mammals, signalling may play a decisive role in mating behavior, mediating theintensity of male fights and female mate choice. During the rutting season, male red deer may show a visible darkpatch in their ventral fur. Recently, this patch has been suggested to act as a flexible sexual signal, due to itsrelationships with other variables such as age, body size, antler development, volatile compounds, or thecompetitive environment. The analysis of fur pigmentation at the ventral patch suggests that this might alsovisually indicate the male intrinsic predisposition to take part in mating competition., [Results]: To assess the possible role of this trait as a communicative signal related to mate competition, we usedred deer behavioral observations during the rut in Doñana National Park (Spain) to examine the link between thedegree of expression of the dark ventral patch and the rutting activity (assessed from both intra-and-inter-sexualbehaviors). Consistent with our predictions, we found in a field study that males with large dark patches showed ahigher frequency of rutting behaviors (mainly roaring and flehmen), more interactions with females, and attainedlarger harem sizes., [Conclusions]: The dark ventral patch was a better predictor of male behavior than antler tines or territory holding,thus standing as a short-term indicator of male willingness to invest in mating competition., Financial support came from projects CGL2013–48122-P and CGL2016–77052-P to JC.

Marriage as a social institution has undergone changes in structure in contemporary Nigeria. Whether in simple or complex societies, social change is a universal phenomenon. In most cultural groups in indigenous Nigeria, marriage is usually an arrangement between two individuals. As a result there is pressure on the spouses to make the marriage a success bearing in mind the fact that any problem will usually affect both families and strain the otherwise cordial relationship between them. Again, polygyny commonly known as polygamy is the most practiced marriage system. However, the marriage structure in Nigeria today has not been the same. It is found in the name of modernization or civilization that a girl and a boy may decide to marry away from their parents’ place of residence and without their consent. Monogamous marriage is now increasingly encouraged and practiced. The paper thus examines the extent of social change in the Nigerian marriage structure.

The labrid fish Pteragogus aurigarius undergoes protogynous (female-to-male) sex change, with dichromatic and dimorphic differences in sexes. Similar to some other protogynous fishes, this species is polygynous. We report the size and age at which sex change occurs by monthly sampling fishes at Tateyama, central Japan, from 2011 to 2012, and investigate conditions of sex change in rearing experiments from 2013 to 2015. Sexual phases are determined using gonad histology, and ages by otolith analysis. Of 231 sampled specimens, 99 were female, 129 were male, and three were intersexual. Of males, 86 resembled typical males, and are referred to as “normal males (NM)”, and 43 resembled females in color, which we refer to as “males with female appearance (MFA)”. NM sizes exceeded those of female, intersexual and MFA individuals. Because intersexual and MFA individuals did not differ in color or size, they may have recently transitioned to being male. Intersexual and MFA individuals ranged 85–135 mm in total length and 1–3 years in age, and appeared from September to March. Because the spawning season runs from June to September, sex change must occur afterwards. Sex change occurred in solitary females, and larger females held with other females in aquaria, both with and without aquarium partitions. Size hierarchy in social groups may be important for sex change of the largest female to male regardless of the number of individuals present.

This article focuses on transnational polygamous marriages of migrants in Russia and how transnational polygynous practices influence people’s understanding of marriage, love and family. The paper shows how polygamous migrant marriages are negotiated between families, by presenting the perspective of individuals involved in such relationships in Russia. It argues that transborder relationships contribute to the transformation of social interactions. People function in two or sometimes more countries, creating opportunities for parallel partnering or other options that influence family networks in the migrants’ countries of origin.

Romantic jealousy is a well-known relational driver of intimate partner violence (IPV), but is under-studied among displaced and polygynous populations. This study aimed to explore factors that elicit jealousy among Somali refugees in the Bokolmayo Refugee camp in Ethiopia, and the pathways leading from jealousy to IPV against women and men, to inform interventions. We conducted an exploratory, thematic analysis of 30 in-depth interviews with both women and men who were Somali refugees, as well as elders and religious leaders, organizational and service providers, policy makers, and host community members. We found that jealousy experienced by women was elicited by an unequal distribution of money and affection between co-wives, which was exacerbated by displacement-related economic hardship, and women in monogamous partnerships suspecting their husband of having other relationships. The jealousy experienced by men was elicited by their wives’ increased financial independence and interactions with other men when working outside of the home, which became more common because of displacement-related economic hardship and relaxed patriarchal gender norms. IPV interventions should address jealousy and controlling behaviors in all relationship types. Addressing conflict and relationship dynamics in polygynous households and in humanitarian settings may require specialized content, acknowledging the complex interactions and resource allocation between co-wives. Gender-transformative interventions that move away from masculinities that are built on the provider role and the introduction of alternative masculinities could also be effective in reducing IPV in this and other similar contexts.

Este trabajo pretende poner de manifiesto que el principio monogámico es característico del matrimonio romano. Desde este contexto, comprender e integrar los principios de las estructuras conyugales del Derecho Romano y seguir su iter histórico-jurídico es esencial a fin de fortalecer el principio monogámico que informa el actual sistema, puesto que dicho principio ofrece las bases tanto de la estructura familiar privada, como de la ordenación y la gestión de lo público en los denominados Estados Sociales y Democráticos de Derecho. This paper aims to show that the monogamous principle is characteristic of Roman marriage. In this context, understanding and integrating the principles of theconjugal structures of Roman law and following its historical-legal iter is essential in order to strengthen the monogamous principle that informs the current system, since this principle provides the basis for both the private family structure and the organisation and management of public affairs in the so-called social and democratic states governed by the rule of law.

The black lion tamarin, Leontopithecus chrysopygus, is an endemic and endangered primate species from the Atlantic Forest of the interior of São Paulo State, Brazil. Its mating system is characterized as monogamous and females give birth to two twin infants during each breeding season. They are known to mainly sleep in tree holes, which is considered as a pertinent strategy for increasing their protection from predators during the night. Artificial cavities, like nest boxes, have been installed for other species in areas where tree cavities are depleted, in order to replace them. In this study, we report (i) the use of nest boxes in the wild by a group of black lion tamarins and (ii) the first record of polygyny for this species.

The world continues to faced many challenges both social and economic as a result of HIV/AIDS. Women in Tanzania and the world at large are among the most vulnerable population to HIV infection. Some of the communities to this day are starved of the critical information about the scourge as a result of the contradictions which emerge between the national laws (i.e., customary law) and international laws. This study aimed primarily at ascertaining the issues of whether polygynous marriage/small house are perceived to expose married women to the high risk of HIV/AIDS. Simple random sampling technique was used to select rural and urban married men/women, especially among those living in polygamous and monogamous marriages and unmarried women who are in relations with married men (small house) at Lushoto in Tanzania. The study noted that married women are at risk of HIV/AIDS when their husbands practice de facto polygyny. As a result of the legal disparities between international laws and national law (i.e., customary law), polygynous marriage/small house exposes married women to a high risk of HIV/AIDS. The international community needs to come up with a standpoint that compels member nations of different cultural practices to ensure that women are not exposed to HIV/AIDS. HIV/AIDS is a reality and dissemination of information to all people should be considered a human right regardless of the different cultural practices. To this end, thousands of married women in polygamous and monogamous marriages are at risk of the scourge in Tanzania in particular and the world in general. The world continues to faced many challenges both social and economic as a result of HIV/AIDS. Women in Tanzania and the world at large are among the most vulnerable population to HIV infection. Some of the communities to this day are starved of the critical information about the scourge as a result of the contradictions which emerge between the national laws (i.e., customary law) and international laws. This study aimed primarily at ascertaining the issues of whether polygynous marriage/small house are perceived to expose married women to the high risk of HIV/AIDS. Simple random sampling technique was used to select rural and urban married men/women, especially among those living in polygamous and monogamous marriages and unmarried women who are in relations with married men (small house) at Lushoto in Tanzania. The study noted that married women are at risk of HIV/AIDS when their husbands practice de facto polygyny. As a result of the legal disparities between international laws and national law (i.e., customary law), polygynous marriage/small house exposes married women to a high risk of HIV/AIDS. The international community needs to come up with a standpoint that compels member nations of different cultural practices to ensure that women are not exposed to HIV/AIDS. HIV/AIDS is a reality and dissemination of information to all people should be considered a human right regardless of the different cultural practices. To this end, thousands of married women in polygamous and monogamous marriages are at risk of the scourge in Tanzania in particular and the world in general.

Infanticide occurs in an array of mammalian species, especially primates. Most infanticidal events occur in polygynous societies, though they sometimes happen in nongregarious populations. We witnessed a possible infanticidal event of a 3-month-old male aye-aye, a species that exhibits a dispersed multimale social system, in Torotorofotsy, Madagascar. Though firsthand killing of the infant was not observed, physical injuries to the infant, vocalizations of the adult female, and her subsequent chase of the adult male aye-aye strongly indicates infanticide. If true, this would be the first recorded incident of an infanticidal event in a noyau primate. The evidence for three different explanations of infanticide is evaluated.

Recent years have seen rising numbers of Malaysian couples contracting cross-border marriages (CBMs) in Southern Thailand to “halalise” (render permissible) romantic relationships and secret polygy...

Divorce emerges as a phenomenon in counterpoint to marriage, both terms representing processes or phases of interaction punctuated by moments of completion and transition to further phases. We can make an initial distinction between divorce, viewed as undoing of preceding phases, and marriage, viewed as prospective of moving into a new relationship. Both divorce and marriage may carry different meanings depending on the wider culture in which they occur. Where marriage comes into being via a series of reciprocal transactions of wealth objects, divorce correspondingly consists of the undoing of such transactions, with the aim of creating a new order of relationships. This process can, in turn, itself vary as it turns on emotional manifestations between the parties involved, sometimes connected with the presence of offspring, as in the case of the Nuer people of South Sudan, among whom a wife does not shift to her husband’s settlement place until the couple have a child. The question of transactions goes with the significance of the wider kin networks in which marriages and divorces are regulated. All in all, our paper examines a counterpoint between legal and emotional aspects of both marriage and divorce, raising issues about what a marriage is and what constitutes a divorce, together with nuances of ritual processes that mark pathways between these categories. We draw on ethnography from Pacific cultures, especially Papua New Guinea, and from Africa, to explore these processes.

Only love to almighty Allah is the greatest love. From ages to ages, Allah has sent his messengers to preach only love to Him. Many destructions, disruptions, and explosions have occurred in this world. This paper tries to explore the causes of the great disasters in the world. The global people when they lead an invalid way, there occurs a terrible crisis. None of the worlds saves it. Only Allah can save global people. Today, the present world is full of share-ism, idolatry-ism, usury-ism, zakat-free-ism, killing-ism, injustice-ism, and inhumanity-ism. They practice about Gods and Goddesses. They believe that the sun, the moon, the stars, the trees, the stone, the angels, the jinn, and other animals can reach Allah. They are the dearest persons who are God, Gods, Goddess, and Goddesses related. Above eleven million people think and say that there is no creator of the universe. It is operating as automated. Marriages and sexism are human to animal. They practice as same-sex, polygamy, polygyny, and polyandry. Most of the global people pray to Materials, Death Guru, God, Gods, Goddess, Goddesses, Peer, Saai, Baba, Abba, Dihi Baba, Langta Baba, Khaja Baba, Joy Guru, Joy Chisty, Joy Baba Hydery, Joy Maa Kali, Maa Durga, Moorshid Kibla, Baba Haque Bhandary, Joy Ganesh Pagla, Joy Deawan Baggi, Joy Chandrapa, Joy Sureshwaree, Fooltali Kebla, Sharshina Kebla, Foorfoora Kebla, Joy Ganapati, Joy Krishnan, Joy Hari, Joy Bhagaban and Mazzarians. The new religions have preached in the world such as Baha’i, Kadyany, Khaljee, Din-E-Elahi, Brahma, and Humanism. The world is full of Shirkism, Moonafikism, Goboatism, Bohtanism, Mooshrikiaism, Oathlessism, and Khianotkariism. In the past, undetermined civilizations have vanished but none can save civilization. This Covid-19 great destruction is human-made. It is from climate change that comes to the global people as a great curse.

Varying forms of polygyny are observed across many animal groups. In some species, a male defends a group of females from other males, and successful defence leads to greater reproductive success. This is often referred to as harem polygyny and is most observed in mammals. A female-biased sex ratio has been associated with harem polygynous species. In such populations, formation of ‘harems’ may be an inevitable consequence of the relative lack of available males, rather than multiple females actively choosing to mate with a subset of specific males. Although a rare mating system for insects, harem polygyny has been described in several orders, including tree wētā (Orthoptera: Anostostomatidae: Hemideina) in New Zealand. Aggregations of multiple females have been found with a single male in their diurnal roosts. We aimed to determine how the sex ratio and local density of Hemideina thoracica affected the formation of harems in laboratory conditions. ‘Harems’ were observed when the sex ratio was female biased, but no more than would be expected by chance arrangement of individuals, although females preferred to associate with males rather than be alone. Conversely, when the sex ratio was male biased, females preferred to be alone. The number of females associated with each male was lowest when the sex ratio was even and local density was low. However, males and females did not associate randomly: when local density was high aggregations of multiple males with multiple females were observed more often than expected by chance, suggesting that, in contrast to classic ‘harem’ behaviour, males accepted other males being present as long as females were also found in the roost. Additionally, females were more likely to be associated with males than in low-density conditions. Individuals in this study showed much more flexibility in their mating behaviour than what would be expected in a harem polygynous species.

The process of growing a family of reaper ants Messor muticus (Nylander, 1849) in a test tube incubator according to the method proposed by G.M. Dlussky and M.P. Bukin (1986) considers its structure and principle of operation. The queens were captured during the flight and identified in accordance with the phylogenetic analysis of F. Steiner. The test ant colonies were divided into 3 experimental and one control groups. The main factors influencing the polygyny development of ant colonies, such as nest size and temperature are considered. The features of the destructive behavior of worker ants and their participation in the regulation of oviparous queens number in the family, as well as the influence of pheromone activity on the relationship between workers and reproductive individuals are described. The main goal of the experiment was to confirm the theory of the effect of nest size and temperature on the development of dimatological colonies of a species with a monogyny family structure. The experiment was carried out for 71 days, observations were recorded every week, the results were summed up on the 8th and 10th weeks of the experiment. The conclusion confirms the theoretical assumptions about the influence of temperature and the size of the primary nest on the development of polygynous colonies of reaper ants Messor muticus. The data obtained can serve as a basis for further study of polygyny in ant colonies, ants behavior in an unnatural habitat and the existence of ants under controlled conditions.

In 2014 the Church of Jesus Christ of Latter-day Saints (LDS Church) updated their official website to include information about the polygamy/polyandry practiced by Joseph Smith, their founder and prophet, and his many wives. The admission by the LDS Church reconciles the tension between information that had become readily available online since the 1990s and church-sanctioned narratives that obscured Smith’s polygamy while concurrently focusing on the polygyny of Brigham Young, Smith’s successor. This paper entwines queer theory with Robert Proctor’s concept of agnotology—a term used to describe the epistemology of ignorance, to consider dissent from two interrelated perspectives: 1) how dissent from feminists and historians within the LDS Church challenged (mis)constructions of Mormon history, and; 2) how the Mormon practice of polygamy in the late nineteenth century dissented from Western sexual mores that conflated monogamy with Whiteness, democracy and social progression in the newly formed American Republic.

Polygyny is marriage between a man and multiple women and is mostly practiced in sub-Saharan African countries. Some of the common attributes of this family structure include perennial conflicts and marital discord, which can expose women to intimate partner violence (IPV). Nonetheless, there is limited research on the intersection between such family structures and IPV in the Ethiopian context. Thus, we examined data from ever-married women (n = 4469) between 15 and 49 years of age collected in the 2016 Ethiopia Demographic and Health Survey (EDHS-2016). Overall, the proportion of polygynous marriages among ever-married Ethiopian women was 10.4% (confidence interval (CI): 8.7–12.4). The prevalences of emotional, physical, and sexual abuse among ever-married women were 24%, 23.1%, and 10.1%, respectively. Women who reported being in polygynous marriages were 1.82 times more likely to report emotional abuse by their husbands (odds ratio (OR) = 1.82; CI: 1.256–2.628). However, the type of marriage had no significant association with physical and sexual violence among ever-married women. The results suggest that polygynous family structures may expose women to IPV. Thus, health and social service providers should be aware of the vulnerability to psychological distress of women in such unions.

Supercolonies of ants are perhaps the largest non-human animal societies, at their largest spanning several millions of individuals and thousands of nests and in invasive species even crossing oceans. Supercolonies have convergently evolved in several ant groups, and they all share a syndrome of key features. First, their colonies spread by budding, which leads to extensive polydomy and inter-nest movement of individuals. Second, local mating and recruitment of queens lead to extensive polygyny. Their ecological dominance is clear, but their evolutionary maintenance is enigmatic due to low relatedness among cooperating individuals and the lack of clear functional organization above local polydomous units. This review takes a multi-level look at the social evolution of supercolonies in an inclusive fitness perspective, outlining key behavioural, ecological, and genetic processes as well as open questions. Such consideration of cooperation and competition from the gene level to the level of populations of supercolonies is necessary for understanding the history and future of supercolonies.

Many species of animals engage in sexual reproduction, a mechanism that allows animal species to evolve to keep up/remain in evolutionary arms races with their predators, prey, and parasites. Mate choice is a core Darwinian attribute in sexually reproducing animals attempting to produce optimum genetic combinations among their offspring. Mate choice played a role in the evolution of sex itself in addition to its current role in behavior and evolution. Competition among animals of the same sex for mates (intrasexual selection) can yield traits that conflict with the expectations of natural selection, such as large horns or antlers. Exaggerated traits result from runaway sexual selection and may cause apparent handicaps in nonmating contexts. Mating systems, such as polygyny, polyandry, and monogamy, can influence the outcome of sexual selection, with high variance in mating success resulting in traits that reflect intense levels of sexual selection. The choice of a mate with “good genes” can involve assessment of traits that are associated with developmental rigor, immunocompetence, the ability to resist parasites, and more.

International audience; En 1222, Mariam de Sebastia, princesse arménienne est en peine : le deuil de ses filles, mortes en bas âge, lui est impossible. Deux cents ans plus tard, bien loin de là, un petit noble savoyard, Antoine d’Arloz, décide, dans son testament, de se faire enterrer dans le chœur de l’église de Leyment, « du côté du vent, au lieu où est situé le banc de son épouse ». Ces témoignages d’affection pour l’autre moitié ou pour les enfants sont saisissants et renvoient à différentes conceptions sensibles de la famille au Moyen Âge. La famille est un corps vivant qui se définit et se remodèle sans cesse, à la faveur de l’irruption de nouveaux membres mais surtout en fonction de normes qu’elle suit ou, en l’occurrence, qu’elle participe à façonner par ses transgressions et/ou ses interprétations. De la péninsule ibérique au Caucase, le volume confronte des aires géographiques, des acteurs sociaux variés et des sources diverses couvrant un long Moyen Âge du VIe au XVe siècle.

To end hunger and increase food security, substantial investments will be required. In sub-Saharan Africa, smallholder agricultural households have a major role to play. However, finding the right instruments to stimulate agricultural growth at the household level requires an accurate understanding of agrarian households’ behaviour. This thesis aimed to contribute to a better understanding of agrarian households, focusing on the institutional conditions shaping cooperation within polygynous households. Indeed, polygynous households are widespread in African societies, but their specific features are relatively neglected in the agricultural development literature. Moreover, the theory of collective action has, so far, been applied at the community-level, but rarely at the intra-household level. To address this knowledge gap, case studies of two ethnic communities, the Fulani and the Mossi, were conducted. The research explored the institutional arrangements shaping the allocation of resources within polygynous households and examined the structural conditions under which cooperation occurs. The second chapter of this thesis reviews the discourse on agricultural households’ behaviour. Reviewing the empirical evidence, the chapter examines the adequacy of existing economic conceptualisations of agricultural households and their generalisability to West-African settings. Drawing on insights from anthropology and feminist perspectives, the chapter highlights the shortcomings of conventional household models, and the failure to consider gender and intergenerational relations of production. The third chapter analyses the challenges underlying cooperation in agricultural households. The chapter uncovers the contractual arrangements shaping the allocation of resources for food production. Drawing on the natural resource management literature, the chapter examines how households’ member’s characteristics, including their socially accepted roles and responsibilities, shape their incentive structures and determine resource pooling. Chapter 4 examines an essential determinant of collective action: trust. The chapter investigates the correlation between trust and productive and reproductive activities. The chapter makes an innovative methodological contribution to the study of cooperation, applying an experimental trust game to co-wives in polygynous households. The critical review of the economic literature challenges the existing representations of agrarian households in sub-Saharan Africa. The review calls for a redefinition of the units of production and for cautious assessment of conventional economic theories. The review recommends a framework that encompasses the complexities and diversity of behaviour in agrarian households. Integrating theories from feminist and anthropological literature can support this endeavour. Chapter 3 reveals that the contractual arrangements embedded in the rules and norms defining socially-accepted behaviour, influence the patterns of intrahousehold resource mobilisation and the likelihood of cooperation among household members. Agricultural household members were found to pool, exchange or split resources based on their roles and positions within the household arena. Implicit monitoring and sanction systems were identified, which shape the incentive structures of agrarian household member and determine whether cooperation will occur. The final chapter revealed that trust can mediate cooperation between co-wives, depending on the nature of the activity. No correlation was found between trust and co-wives’ likelihood to pool labour on individual plots. However, a strong correlation was identified between trust among co-wives and income pooling for food purchase, highlighting the importance of uncertainty and of existing norms on the outcomes of cooperation in agricultural households. The thesis concludes that collective action in polygynous agrarian households does not occur in a vacuum. Rather, collective action is the outcome of several processes and mechanisms. Policymakers should be aware of these internal arrangements, and their implications for intra-household resource allocation. The success of agricultural policies depends on these considerations. Um den Hunger zu beenden und die Ernährungssicherheit zu erhöhen, sind erhebliche Investitionen erforderlich. In Subsahara-Afrika spielen landwirtschaftliche Kleinbauernhaushalte eine wichtige Rolle. Die Suche nach den richtigen Instrumenten zur Stimulierung des landwirtschaftlichen Wachstums auf Haushaltsebene erfordert jedoch ein genaues Verständnis des Verhaltens der Agrarhaushalte. Ziel dieser Arbeit war es, zu einem besseren Verständnis agrarischer Haushalte beizutragen, wobei der Schwerpunkt auf den institutionellen Bedingungen liegt, die die Zusammenarbeit in polygynen Haushalten prägen. Tatsächlich sind polygyne Haushalte in afrikanischen Gesellschaften weit verbreitet, aber ihre Besonderheiten werden in der Literatur zur landwirtschaftlichen Entwicklung relativ vernachlässigt. Darüber hinaus wurde die Theorie des kollektiven Handelns bisher auf Gemeindeebene, aber selten auf haushaltsinterner Ebene angewandt. Um diese Wissenslücke zu schließen, wurden Fallstudien zu zwei ethnischen Gemeinschaften, den Fulani und den Mossi, durchgeführt. Die Forschung untersuchte die Regeln und Normen, Ressourcenverteilung innerhalb polygyner Agrarhaushalte prägen, und untersuchte die strukturellen Bedingungen, unter denen Kooperation stattfindet. Das zweite Kapitel dieser Arbeit befasst sich mit dem Diskurs über das Verhalten landwirtschaftlicher Haushalte. Das Kapitel überprüft die empirische Evidenz und untersucht die Angemessenheit bestehender ökonomischer Konzeptualisierungen landwirtschaftlicher Haushalte und ihre Verallgemeinerbarkeit auf westafrikanische Rahmenbedingungen. Das Kapitel stützt sich auf Erkenntnisse aus anthropologischer und feministischer Perspektive und beleuchtet die Mängel herkömmlicher Haushaltsmodelle und die fehlende Berücksichtigung von Geschlechter- und generationsübergreifenden Produktionsverhältnissen. Das dritte Kapitel analysiert die Herausforderungen, die der Zusammenarbeit in landwirtschaftlichen Haushalten zugrunde liegen. Das Kapitel deckt die vertraglichen Vereinbarungen auf, die die Zuweisung von Ressourcen für die Nahrungsmittelproduktion formen. Unter Bezugnahme auf die Literatur zum Management natürlicher Ressourcen untersucht das Kapitel, wie die Merkmale der Haushaltsmitglieder, einschließlich ihrer sozial akzeptierten Rollen und Verantwortlichkeiten, ihre Anreizstrukturen formen und die Ressourcenbündelung bestimmen. Kapitel 4 untersucht eine wesentliche Determinante kollektiven Handelns: Vertrauen. Das Kapitel untersucht den Zusammenhang zwischen Vertrauen und produktiven und reproduktiven Aktivitäten. Das Kapitel leistet einen innovativen methodologischen Beitrag zur Erforschung von Kooperation, indem es ein experimentelles Vertrauensspiel auf Co-Ehefrauen in polygynen Haushalten anwendet. Die kritische Überprüfung der wirtschaftswissenschaftlichen Literatur hinterfragt die bestehenden Darstellungen von Agrarhaushalten in Subsahara-Afrika. Die Überprüfung fordert eine Neudefinition der Produktionseinheiten und eine vorsichtige Bewertung herkömmlicher Wirtschaftstheorien. Die Überprüfung empfiehlt einen Rahmen, der die Komplexität und Vielfalt des Verhaltens in landwirtschaftlichen Haushalten umfasst. Die Integration von Theorien aus feministischer und anthropologischer Literatur kann dieses Bestreben unterstützen. Kapitel 3 zeigt, dass die vertraglichen Vereinbarungen, die in die Regeln und Normen eingebettet sind, die sozial akzeptiertes Verhalten definieren, die Muster der haushaltsinternen Ressourcenmobilisierung und die Wahrscheinlichkeit beeinflussen Zusammenarbeit unter den Haushaltsmitgliedern. Es wurde festgestellt, dass landwirtschaftliche Haushaltsmitglieder Ressourcen basierend auf ihren Rollen und Positionen innerhalb des Haushaltsbereichs zusammenlegen, austauschen oder aufteilen. Es wurden implizite Kontroll- und Sanktionssysteme identifiziert, die die Anreizstrukturen der agrarischen Haushaltsmitglieder prägen und über Kooperation entscheiden. Das letzte Kapitel zeigte, dass Vertrauen je nach Art der Aktivität die Zusammenarbeit zwischen Co-Ehefrauen vermitteln kann. Es wurde keine Korrelation zwischen dem Vertrauen und der Wahrscheinlichkeit der Mitfrauen gefunden, die Arbeitskräfte auf einzelnen Parzellen zusammenzulegen. Es wurde jedoch eine starke Korrelation zwischen dem Vertrauen unter Co-Ehefrauen und dem Einkommenspooling für den Lebensmittelkauf festgestellt, was die Bedeutung von Unsicherheit und bestehenden Normen auf der Ergebnisse der Zusammenarbeit in landwirtschaftlichen Haushalten. Die Arbeit kommt zu dem Schluss, dass kollektives Handeln in polygynen Agrarhaushalten nicht Vakuum stattfindet. Kollektives Handeln ist vielmehr das Ergebnis mehrerer Prozesse und Mechanismen. Politische Entscheidungsträger sollten sich dieser internen Vereinbarungen und ihrer Auswirkungen auf die haushaltsinterne Ressourcenallokation bewusst sein. Von diesen Überlegungen hängt der Erfolg der Agrarpolitik ab.

This essay explores a model for inequality in Nigerian rural Hausaland based on fieldwork carried out from 1977 to 1979, with follow-up visits in 1996 and from 1997 to 1998. In the model, rural dif...

The fire ant Solenopsis invicta exists in two alternate social forms: monogyne nests contain a single reproductive queen and polygyne nests contain multiple reproductive queens. This colony-level social polymorphism corresponds with individual differences in queen physiology, queen dispersal patterns and worker discrimination behaviours, all evidently regulated by an inversion-based supergene that spans more than 13 Mb of a "social chromosome," contains over 400 protein-coding genes and rarely undergoes recombination. The specific mechanisms by which this supergene influences expression of the many distinctive features that characterize the alternate forms remain almost wholly unknown. To advance our understanding of these mechanisms, we explore the effects of social chromosome genotype and natal colony social form on gene expression in queens sampled as they embarked on nuptial flights, using RNA-sequencing of brains and ovaries. We observe a large effect of natal social form, that is, of the social/developmental environment, on gene expression profiles, with similarly substantial effects of genotype, including: (a) supergene-associated gene upregulation, (b) allele-specific expression and (c) pronounced extra-supergene trans-regulatory effects. These findings, along with observed spatial variation in differential and allele-specific expression within the supergene region, highlight the complex gene regulatory landscape that emerged following divergence of the inversion-mediated Sb haplotype from its homologue, which presumably largely retained the ancestral gene order. The distinctive supergene-associated gene expression trajectories we document at the onset of a queen's reproductive life expand the known record of relevant molecular correlates of a complex social polymorphism and point to putative genetic factors underpinning the alternate social syndromes.

Gender plays a prominent role in many aspects of political violence. First, it contributes to its occurrence. Second, sexual violence causes enormous suffering during conflict. Last, sustainable peacekeeping depends on female inclusion and participation. The prominence of gender in political violence rests on the dominance of men over women in many aspects of political, social and economic life. Inequities in family law and perversions in the marriage market, especially polygyny, contribute to the perpetuation of male dominance hierarchies in ways that increase the likelihood and costs of political violence for everyone.

Intraspecific variation in mating behavior has been documented in diverse taxa, including ungulates. Here, we report and describe for the first time the existence of alternative mating tactics in a wild guanaco (Lama guanicoe) partially migratory population. We document (1) a resource-defense tactic, widely reported for different populations; and (2) a clustered territorial tactic, adopted by the solo territorial males of this population. Our results highlight the reproductive flexibility of this species and its relationship with external factors that could be influencing it. La variación intraespecífica en el comportamiento de apareamiento ha sido documentada en diversos taxones, incluyendo ungulados. Aquí reportamos y describimos por primera vez la existencia de tácticas alternativas de apareamiento en una población de guanacos silvestres (Lama guanicoe) parcialmente migratoria. Documentamos (1) una táctica de defensa de los recursos, ampliamente descripta para diferentes poblaciones; y (2) una táctica territorial agrupada, adoptada por los machos territoriales solitarios de esta población. Nuestros resultados destacan la flexibilidad reproductiva de esta especie y su relación con los factores externos que podrían estar influyendo en ella. Fil: Panebianco, Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Gregorio, Pablo Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Ovejero Aguilar, Ramiro Jose Antonio. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentina. Universidad Austral de Chile; Chile Fil: Marozzi, Antonela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Leggieri, Leonardo Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Taraborelli, Paula Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Carmanchahi, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina

In accordance with predictions of the size-advantage model, comparative evidence confirms that protogynous sex change is lost when mating behavior is characterized by weak size advantage. However, we lack comparative evidence supporting the adaptive significance of sex change. Specifically, it remains unclear whether increasing male size advantage induces transitions to protogynous sex change across species, as it can within species. We show that in wrasses and parrotfishes (Labridae), the evolution of protogynous sex change is correlated with polygynous mating, and that the degree of male size advantage expressed by polygynous species influences transitions between different types of protogynous sex change. Phylogenetic reconstructions reveal strikingly similar patterns of sex allocation and mating system evolution with comparable lability. Despite the plasticity of sex determination mechanisms in labrids, transitions trend towards monandry (all males derived from sex-changed females), with all observed losses of protogyny accounted for by shifts in the timing of sex change to prematuration. Likewise, transitions in mating system trend from the ancestral condition of lek-like polygyny toward greater male size advantage, characteristic of haremic polygyny. The results of our comparative analyses are among the first to confirm the adaptive significance of sex change as described by the size-advantage model.

Why would a woman agree to wed a legally married man when the state would neither recognize her marriage nor grant her alimony, child support or inheritance rights? Although the Communist Party cur...

Ungulates exhibit diverse mating systems that range from monogamous pair territories to highly polygynous leks. We review mating systems and behaviors across ungulates and offer a new approach synthesizing how interacting factors may shape those mating systems. Variability exists in mating systems among and within species of ungulates and likely is affected by predation risk, availability of resources (food and mates), habitat structure, and sociality. Ungulate mating systems may be labile as a consequence of the varying strength of those interacting factors. In addition, degree of polygyny and sexual dimorphism in size are associated with the evolution of mating systems. Neither male–male combat nor paternal care, however, can completely explain differences in sexual size dimorphism for ungulates, a necessary component in understanding the development of some mating systems. Whatever the evolutionary pathway, sexual segregation limits paternal care allowing more intense male–male competition. Selection of habitat structure, because it modifies risk of predation, is a major determinant of sociality for ungulates. Likewise, ruggedness and steepness of terrain limit the types of mating systems that can occur because of limitations in group size and cohesiveness, as well as the ability of males to herd even small groups of females effectively. The quality and defensibility of resources affect mating systems, as does the defensibility of females. Population density of females also may be a critical determinant of the types of mating systems that develop. Size of groups likewise constrains the types of mating tactics that males can employ. Our aim was to use those relationships to create a broad conceptual model that predicts how various environmental and social factors interact to structure mating systems in ungulates. This model provides a useful framework for future tests of the roles of both ecological and social conditions in influencing the social systems of ungulates., We provide a new approach to understanding mating systems in ungulates. We integrate both social and environmental factors in doing so. We develop a predictive model to help understand the evolution of these unique behaviors, which should help to direct future studies.

Mating with multiple partners is common across animal taxa. Males mate multiply because reproductive success positively correlates with mating success. In contrast, multiple mating is expected to increase the direct (material) or indirect (genetic) benefits accrued by females but not necessarily increase their reproductive success. Cases in which female reproductive success increases with mating success could be due to females acquiring material resources that directly increase reproductive output. Because multiple mating likely increases reproductive success more in males than in females, males typically experience greater sexual selection. Consequently, males in harem polygynous species, where a few males can monopolize access to several females in a population, are expected to be under stronger sexual selection than females. We field-test these predictions by using the harem polygynous Wellington tree wētā, Hemideina crassidens. Here, we develop microsatellite markers for H. crassidens and use them to genotype females, their offspring and putative sires to estimate the opportunity for selection as well as quantify natural rates of multiple mating and its effect on male and female reproductive success (number of hatchlings). We found that both sexes mate multiply and that reproductive success increases with mating success in both sexes. Males and females have similar total opportunities for selection, and sexual selection comprises approximately 50% of the total selection operating in males. We found that female oviposition rate increases with mating success, but we found no evidence to support the hypothesis that females derive indirect benefits from polyandry. Our study provides strong evidence that male and female H. crassidens derive significant direct fitness benefits from multiple mating under natural conditions.

Polygyny is practised in vastly different cultural contexts, including in Papua New Guinea (PNG). The literature is contradictory, arguing that polygyny is either protective against HIV or a critic...

We investigated the mating system of three sex changing gobiid fishes: Priolepis akihitoi, Trimma emeryi, and Trimma hayashii by underwater observation or specimen collection. P. akihitoi were found in pairs or were solitary. As the pair bond persisted for at least two months, and pair individuals seemed to mate with each other repeatedly, a monogamous mating system was suggested in P. akihitoi. In contrast, the harem-like group (living in a group composed of one largest male and some smaller females and/or immature individuals) of T. hayashii and T. emeryi suggested that these species have harem polygyny.