686,380 research outputs found

    Experimental evidence for kin-biased helping in a cooperatively breeding vertebrate

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    The widespread belief that kin selection is necessary for the evolution of cooperative breeding in vertebrates has recently been questioned. These doubts have primarily arisen because of the paucity of unequivocal evidence for kin preferences in cooperative behaviour. Using the cooperative breeding system of long-tailed tits (Aegithalos caudatus) in which kin and non-kin breed within each social unit and helpers are failed breeders, we investigated whether helpers preferentially direct their care towards kin following breeding failure. First, using observational data, we show that not all failed breeders actually become helpers, but that those that do help usually do so at the nest of a close relative. Second, we confirm the importance of kinship for helping in this species by conducting a choice experiment. We show that potential helpers do not become helpers in the absence of close kin and, when given a choice between helping equidistant broods belonging to kin and non-kin within the same social unit, virtually all helped at the nest of kin. This study provides strong evidence that kinship plays an essential role in the maintenance of cooperative breeding in this species

    Human kin detection

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    Natural selection has favored the evolution of behaviors that benefit not only one's genes, but also their copies in genetically related individuals. These behaviors include optimal outbreeding (choosing a mate that is neither too closely related, nor too distant), nepotism (helping kin), and spite (hurting non-kin at a personal cost), and all require some form of kin detection or kin recognition. Yet, kinship cannot be assessed directly; human kin detection relies on heuristic cues that take into account individuals' context (whether they were reared by our mother, or grew up in our home, or were given birth by our spouse), appearance (whether they smell or look like us), and ability to arouse certain feelings (whether we feel emotionally close to them). The uncertainties of kin detection, along with its dependence on social information, create ample opportunities for the evolution of deception and self-deception. For example, babies carry no unequivocal stamp of their biological father, but across cultures they are passionately claimed to resemble their mother's spouse; to the same effect, neutral' observers are greatly influenced by belief in relatedness when judging resemblance between strangers. Still, paternity uncertainty profoundly shapes human relationships, reducing not only the investment contributed by paternal versus maternal kin, but also prosocial behavior between individuals who are related through one or more males rather than females alone. Because of its relevance to racial discrimination and political preferences, the evolutionary pressure to prefer kin to non-kin has a manifold influence on society at large

    Nepotistic patterns of violent psychopathy: evidence for adaptation?

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    Psychopaths routinely disregard social norms by engaging in selfish, antisocial, often violent behavior. Commonly characterized as mentally disordered, recent evidence suggests that psychopaths are executing a well-functioning, if unscrupulous strategy that historically increased reproductive success at the expense of others. Natural selection ought to have favored strategies that spared close kin from harm, however, because actions affecting the fitness of genetic relatives contribute to an individual’s inclusive fitness. Conversely, there is evidence that mental disorders can disrupt psychological mechanisms designed to protect relatives. Thus, mental disorder and adaptation accounts of psychopathy generate opposing hypotheses: psychopathy should be associated with an increase in the victimization of kin in the former account but not in the latter. Contrary to the mental disorder hypothesis, we show here in a sample of 289 violent offenders that variation in psychopathy predicts a decrease in the genetic relatedness of victims to offenders; that is, psychopathy predicts an increased likelihood of harming non-relatives. Because nepotistic inhibition in violence may be caused by dispersal or kin discrimination, we examined the effects of psychopathy on (1) the dispersal of offenders and their kin and (2) sexual assault frequency (as a window on kin discrimination). Although psychopathy was negatively associated with coresidence with kin and positively associated with the commission of sexual assault, it remained negatively associated with the genetic relatedness of victims to offenders after removing cases of offenders who had coresided with kin and cases of sexual assault from the analyses. These results stand in contrast to models positing psychopathy as a pathology, and provide support for the hypothesis that psychopathy reflects an evolutionary strategy largely favoring the exploitation of non-relatives

    Identifying systems barriers that may prevent bereavement service access to bereaved carers: A report from an Australian specialist palliative care service

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    Background: Bereavement follow up is an integral element of palliative care. However, little is known about the systems that link bereavement services with bereaved carers. Aim: To map how effectively a specialist palliative care service linked bereavement service to bereaved carers. Methodology: A retrospective medical audit, using process mapping was undertaken within one Australian specialist palliative care service to identify the systems that linked bereavement services to a consecutive cohort of palliative care decedents (n=60) next of kin. Results: Bereavement records were located for 80% of decedents. Nearly all (98%) had a nominated next of kin, with just over half (54%) of those nominated contacted by bereavement services. Incomplete or missing contact details was the main reason (75%) that the bereavement service was unable to contact the decedents’ next of kin. Conclusion: Having access to a designated bereavement service can ensure that bereaved next of kin are contract routinely and in a timely way. However the effectiveness of this type of service is dependent upon the bereavement service having access to all relevant contact information. There are numerous opportunities to refine and strengthen the recording of palliative care next of kin details to optimize follow up

    Minimal dilatations of pseudo-Anosovs generated by the magic 3-manifold and their asymptotic behavior

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    This paper concerns the set M^\hat{\mathcal{M}} of pseudo-Anosovs which occur as monodromies of fibrations on manifolds obtained from the magic 3-manifold NN by Dehn filling three cusps with a mild restriction. We prove that for each gg (resp. g≢0(mod6)g \not\equiv 0 \pmod{6}), the minimum among dilatations of elements (resp. elements with orientable invariant foliations) of M^\hat{\mathcal{M}} defined on a closed surface Σg\varSigma_g of genus gg is achieved by the monodromy of some Σg\varSigma_g-bundle over the circle obtained from N(32)N(\tfrac{3}{-2}) or N(12)N(\tfrac{1}{-2}) by Dehn filling two cusps. These minimizers are the same ones identified by Hironaka, Aaber-Dunfiled, Kin-Takasawa independently. In the case g6(mod12)g \equiv 6 \pmod{12} we find a new family of pseudo-Anosovs defined on Σg\varSigma_g with orientable invariant foliations obtained from N(-6) or N(4) by Dehn filling two cusps. We prove that if δg+\delta_g^+ is the minimal dilatation of pseudo-Anosovs with orientable invariant foliations defined on Σg\varSigma_g, then lim supg6(mod12)gglogδg+2logδ(D5)1.0870, \limsup_{\substack{g \equiv 6 \pmod{12} g \to \infty}} g \log \delta^+_g \le 2 \log \delta(D_5) \approx 1.0870, where δ(Dn)\delta(D_n) is the minimal dilatation of pseudo-Anosovs on an nn-punctured disk. We also study monodromies of fibrations on N(1). We prove that if δ1,n\delta_{1,n} is the minimal dilatation of pseudo-Anosovs on a genus 1 surface with nn punctures, then lim supnnlogδ1,n2logδ(D4)1.6628. \limsup_{n \to \infty} n \log \delta_{1,n} \le 2 \log \delta(D_4) \approx 1.6628. Comment: 46 pages, 14 figures; version 3: Major change in Section 2.1, and minor correction

    CHAPTER 8: DWIGHT READ: TOWARDS A NEW PARADIGM: FOLLOWED BY A DISCUSSION BETWEEN THE AUTHOR AND DWIGHT READ

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    Here I report on Dwight Read’s theory for a paradigm change in kinship anthropology which entails kinship terminologies being interpreted as symbolic computational systems based on kin-term products. I also report on how Read argues that different conceptualizations of sibling, either sibling resulting by descent from parent, or sibling viewed in terms of shared parentage, two cultural conceptions that are rendered – here exemplifying the masculine side – by the kin-term products, S o F = B [son of father = brother] or F o B = F [father of brother = father), lead to respectively building up a descriptive or a classificatory terminology. The chapter also deals with how Dwight Read accounts for the relationship between genealogical tracing and the working out of kin terms using kin-term products and how the logic of kin-term products is consistent with the extension of kin terms to kin-type categories beyond the primary ones.The paper also reports on a discussion between Dwight Read and the author, initiated by questions and observations from the latter, regarding different aspects of Read’s reasoning. Not exhaustively, to be mentioned here is the way kin relationships are concretely worked out using kin-term products, the model of the family space and the nuclear family, group marriage,  how the conceptualization of sibling in terms of shared parentage expressed through the kin-term product F o B = F [father o brother = father] relates to ethnographic data, the nature of the logic of kinship terminologies, the status of the structural equation S o F = B [son o father = brother] when used within the context of a classificatory terminology, the axiomatic nature of a number of kin-term products pertaining to specific kin terminologies, the equations pertaining to classificatory kinship terminologies that are  likely to algebraically reduce chains of kin-terms products, mapped from corresponding kin type strings, like “son of son of father of father of father” (S o S o F o F o F) is mapped from the collateral genealogical relations, father’s father’s father’s son’s son (fffss or fffbss) to an irreducible kin term, here father, which is the one native speakers use for the said genealogical connection.The discussion also addresses, taking the example of ancient Chinese dialects, the question of what should be the structural prerequisites for a transition from classificatory (Dravidian) terminologies into bifurcate collateral and descriptive terminologies, a transition that is often posited by a number of linguists and anthropologists. Finally, the discussion deals with the question as to whether the kinship terminologies of the world all ultimately derive from a pre-dispersal African Proto-Sapiens kinship terminology. Throughout these lines of discussion, the central question is raised as to why different cultural choices on how siblings are conceptualized were made that led to different human kinship terminologies and social structures

    The Pig Story (Tiboi Sakkoko) Storytelling of Kinship, Memories of the Past, and Rights to Plots of Ancestral Land in Mentawai

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    This paper examines some significant elements of the pig story (tiboi sakkoko). This tale contains crucial information about the collective identity, ancestors and historical events affecting particular Mentawai kin-groups. As families do not preserve their culture and traditions in written form, storytellers of kin-groups have narrated the pig story from generation to generation so as to preserve it carefully. In the course of time, storytellers establish particular ways of telling their stories so as to remember the content and plot of the stories easily. Through the pig story, members of kin groups also recollect their ancestral place of origin and plots of ancestral lands. The role of human memory is indispensable to recalling all these important elements. Therefore, this paper analyses memories of the past of different family generations. To achieve its aims, this paper also evaluates the roles of family stories in the culture and traditions of Mentawai society
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