39 research outputs found

    Mass extinctions drove increased global faunal cosmopolitanism on the supercontinent Pangaea

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    Mass extinctions have profoundly impacted the evolution of life through not only reducing taxonomic diversity but also reshaping ecosystems and biogeographic patterns. In particular, they are considered to have driven increased biogeographic cosmopolitanism, but quantitative tests of this hypothesis are rare and have not explicitly incorporated information on evolutionary relationships. Here we quantify faunal cosmopolitanism using a phylogenetic network approach for 891 terrestrial vertebrate species spanning the late Permian through Early Jurassic. This key interval witnessed the Permian–Triassic and Triassic–Jurassic mass extinctions, the onset of fragmentation of the supercontinent Pangaea, and the origins of dinosaurs and many modern vertebrate groups. Our results recover significant increases in global faunal cosmopolitanism following both mass extinctions, driven mainly by new, widespread taxa, leading to homogenous ‘disaster faunas’. Cosmopolitanism subsequently declines in post-recovery communities. These shared patterns in both biotic crises suggest that mass extinctions have predictable influences on animal distribution and may shed light on biodiversity loss in extant ecosystems

    Men's passage to fatherhood: an analysis of the contemporary relevance of transition theory

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    This paper presents a theoretical analysis of men's experiences of pregnancy, birth and early fatherhood. It does so using a framework of ritual transition theory and argues that despite its earlier structural-functionalist roots, transition theory remains a valuable framework, illuminating contemporary transitions across the life course. The paper discusses the historical development of transition or ritual theory and, drawing upon data generated during longitudinal ethnographic interviews with men undergoing the transition to fatherhood, analyses its relevance in understanding contemporary experiences of fatherhood

    Neurodevelopmental milestones and associated behaviours are similar among healthy children across diverse geographical locations.

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    It is unclear whether early child development is, like skeletal growth, similar across diverse regions with adequate health and nutrition. We prospectively assessed 1307 healthy, well-nourished 2-year-old children of educated mothers, enrolled in early pregnancy from urban areas without major socioeconomic or environmental constraints, in Brazil, India, Italy, Kenya and UK. We used a specially developed psychometric tool, WHO motor milestones and visual tests. Similarities across sites were measured using variance components analysis and standardised site differences (SSD). In 14 of the 16 domains, the percentage of total variance explained by between-site differences ranged from 1.3% (cognitive score) to 9.2% (behaviour score). Of the 80 SSD comparisons, only six were >±0.50 units of the pooled SD for the corresponding item. The sequence and timing of attainment of neurodevelopmental milestones and associated behaviours in early childhood are, therefore, likely innate and universal, as long as nutritional and health needs are met

    Competitive Interactions between Invasive Nile Tilapia and Native Fish: The Potential for Altered Trophic Exchange and Modification of Food Webs

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    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important

    Sexuality among Fathers of Newborns in Jamaica

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    Background While a growing body of research has addressed pregnancy and postpartum impacts on female sexuality, relatively little work has been focused upon men. A few studies suggest that a fraction of men report decreases in libido during a partner’s pregnancy and/or postpartum, with alterations in men’s sexual behavior also commonly aligning with those of a partner. Here, we investigate sexuality among fathers of newborn children in Jamaica. In Jamaica, as elsewhere in the Caribbean, relationship dynamics can be fluid, contributing to variable paternal roles and care, as well as a high fraction of children born into visiting relationships in which parents live apart from each other. Methods During July-September, 2011, 3410 fathers of newborns with an average age of 31 (SD = 8) years participated in the fatherhood arm of a national birth cohort study (JAKids). These fathers answered questions about sociodemographic background, relationship quality and sexuality (e.g., various components of sexual function such as sex drive and sexual satisfaction as well as number of sexual partners the previous 12 months and sexual intercourse the previous week) during a visit to a hospital or birth center within a day or two of their child being born. Results Showed that sex drive was more variable than other components (erections, ejaculation, problem assessment) of sexual function, though sexual satisfaction was generally high. Thirty percent of men reported two or more sexual partners the previous 12 months. Nearly half of men indicated not engaging in sexual intercourse the past week. Multivariate analyses showed that relationship status was related to various aspects of men’s sexuality, such as men in visiting relationships reporting more sexual partners and more openness to casual sex. Relationship quality was the most consistent predictor of men’s sexuality, with men in higher quality relationships reporting higher sexual satisfaction, fewer sexual partners, and higher frequency of sex, among other findings. Conclusions These results provide an unusually large, quantitative look at men’s sexuality during the transition to fatherhood in Jamaica, offering helpful insight to would-be parents, clinicians or others seeking to anticipate the effects of a partner’s pregnancy on men’s sexuality

    The perceptions of young adult adoptees in India on their emotional well-being

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    This article presents the findings of a study of 46 adults adopted at very young ages in India and now aged between 20 and 30 years. The results suggest that the majority of respondents were physically healthy and well adjusted. However, 40% scored below the norm for social functioning, suggesting some underlying issues associated with poor well-being in their current phase of life. The mental health issues affecting the young people were associated more with anxiety and stress than depression. However, none of the variables investigated proved to be strong predictors of mental health difficulties. The results are discussed in the context of Indian culture and psychosocial development during early adulthood and include implications for practice
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