40 research outputs found

    The evolution of social traits and biodiversity in the ants.

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    Cooperation has shaped the evolution of life on Earth. The ants are the most numerically diverse of the eusocial Hymenoptera, and display wide variation in social complexity. This positions the ants as an ideal taxon in which to study social evolution in a comparative framework. Social evolution theory has generated many hypotheses that are testable in ants, however the lack of comprehensive or complete phylogenies, and the decentralised and scattered nature of trait data, has been an obstacle to these types of study. In this thesis I construct a large species-level, and a complete genus-level, phylogeny of the ants, and draw together a large dataset of social traits from the literature in order to test hypotheses concerning the evolution of social traits in the ants. I find evidence that the earliest ant was large bodied, and lived in small highly related colonies. I show that group size is a significant trait in the evolution of sociality in ants, predicting the probability of a species having polymorphic workers, or of being polyandrous. I also show that the change in these traits is correlated between ancestral nodes on the phylogeny. Furthermore, in the Attini, colony size correlates closely with non-reproductive and reproductive division of labour. Together these results cement group size as a driving force of social evolution in the ants, and this has interesting implications for social evolution in general. Finally, I report the first evidence that intermediate colony sizes, the presence of discrete worker castes and polygyny are associated with increased diversification rates in ants. This thesis provides a valuable tool for the study of comparative hypotheses in the ants in the form of a complete genus-level phylogeny, and offers significant evidence to support several key hypotheses in social evolution. Furthermore, these results generate hypotheses regarding the evolution of social traits for future research

    Rapid decreases in relative testes mass among monogamous birds but not in other vertebrates

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    Larger testes produce more sperm and therefore improve reproductive success in the face of sperm competition. Adaptation to social mating systems with relatively high and low sperm competition are therefore likely to have driven changes in relative testes size in opposing directions. Here, we combine the largest vertebrate testes mass dataset ever collected with phylogenetic approaches for measuring rates of morphological evolution to provide the first quantitative evidence for how relative testes mass has changed over time. We detect explosive radiations of testes mass diversity distributed throughout the vertebrate tree of life: bursts of rapid change have been frequent during vertebrate evolutionary history. In socially monogamous birds, there have been repeated rapid reductions in relative testes mass. We see no such pattern in other monogamous vertebrates; the prevalence of monogamy in birds may have increased opportunities for investment in alternative behaviours and physiologies allowing reduced investment in expensive testes

    The evolution of masturbation is associated with postcopulatory selection and pathogen avoidance in primates

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    Masturbation occurs throughout the animal kingdom. At first glance, however, the fitness benefits of this self-directed behaviour are unclear. Regardless, several drivers have been proposed. Non-functional hypotheses posit that masturbation is either a pathology, or a byproduct of high underlying sexual arousal, whereas functional hypotheses argue an adaptive benefit. The Postcopulatory Selection Hypothesis states that masturbation aids the chances of fertilization, while the Pathogen Avoidance Hypothesis states that masturbation helps reduce host infection by flushing pathogens from the genital tract. Here, we present comprehensive new data documenting masturbation across the primate order and use these, in conjunction with phylogenetic comparative methods, to reconstruct the evolutionary pathways and correlates of masturbation. We find that masturbation is an ancient trait within the primate order, becoming a more common aspect of the haplorrhine behavioural repertoire after the split from tarsiers. Our analyses provide support for both the Postcopulatory Selection and Pathogen Avoidance Hypotheses in male primates, suggesting that masturbation may be an adaptive trait, functioning at a macroevolutionary scale

    Potential for positive biodiversity outcomes under diet-driven land use change in Great Britain

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    Background: A shift toward human diets that include more fruit and vegetables, and less meat is a potential pathway to improve public health and reduce food system-related greenhouse gas emissions. Associated changes in land use could include conversion of grazing land into horticulture, which makes more efficient use of land per unit of dietary energy and frees-up land for other uses. Methods: Here we use Great Britain as a case study to estimate potential impacts on biodiversity from converting grazing land to a mixture of horticulture and natural land covers by fitting species distribution models for over 800 species, including pollinating insects and species of conservation priority. Results: Across several land use scenarios that consider the current ratio of domestic fruit and vegetable production to imports, our statistical models suggest a potential for gains to biodiversity, including a tendency for more species to gain habitable area than to lose habitable area. Moreover, the models suggest that climate change impacts on biodiversity could be mitigated to a degree by land use changes associated with dietary shifts. Conclusions: Our analysis demonstrates that options exist for changing agricultural land uses in a way that can generate win-win-win outcomes for biodiversity, adaptation to climate change and public healt

    Potential for positive biodiversity outcomes under diet-driven land use change in Great Britain

    Get PDF
    •Background: A shift toward human diets that include more fruit and vegetables, and less meat is a potential pathway to improve public health and reduce food system-related greenhouse gas emissions. Associated changes in land use could include conversion of grazing land into horticulture, which makes more efficient use of land per unit of dietary energy and frees-up land for other uses. •Methods: Here we use Great Britain as a case study to estimate potential impacts on biodiversity from converting grazing land to a mixture of horticulture and natural land covers by fitting species distribution models for over 800 species, including pollinating insects and species of conservation priority. •Results: Across several land use scenarios that consider the current ratio of domestic fruit and vegetable production to imports, our statistical models suggest a potential for gains to biodiversity, including a tendency for more species to gain habitable area than to lose habitable area. Moreover, the models suggest that climate change impacts on biodiversity could be mitigated to a degree by land use changes associated with dietary shifts. •Conclusions: Our analysis demonstrates that options exist for changing agricultural land uses in a way that can generate win-win-win outcomes for biodiversity, adaptation to climate change and public health

    Social Class

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    Discussion of class structure in fifth-century Athens, historical constitution of theater audiences, and the changes in the comic representation of class antagonism from Aristophanes to Menander

    The Lantern, 2015-2016

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    • Ghosts • Going to China • 98% Guaranteed • Constellation/Boulevard • Prayer • The Little One • Burning • The Amber Macaroon • Becoming • Requiem • Construction Site • Thirteen Ways of Looking at a Dragon • Charlie • No Sleep • A Lesson in Physical Education • Statues • Who Can Love a Black Woman? • Apples • Fun Craft • The Door at Midnight • Eve as a Book in the Bible • Boys • Diamond Heart • To Apollo • Joanne and Her July Garden • Option A, 1936 • Young White Girls, Hollow Bodies, and Home • Mama\u27s Stance on Sugar • The Mariana Trench • Hurricane • Part of the Job • Avenue H Blues • Hour of Nones • Send Toilet Paper • Grave Robbing • Wild Turkey • The Creek • Let\u27s Go for a Walk • Deaconess • Border of Love • Your Father, Rumpelstiltskin • Purchasing Poplars • Red Tatters • Sunken • Whispers • Existence • God Took a Cigarette Break with Police Officers • Martian Standoff • In the Headlights • It\u27s a Subtle Thing • Dear Kent • Hanako-san • A Brief Interlude • On Fencing, Gummy Worms, and my Inescapable Fear of Living in the Moment • Stolen Soul • Block • Mortem Mei Fratris • Kalki • Lake Placid • Atom and Eve • The Baerie Queene • Gladston • Soldiers at Gettysburg • Pattern • Foliage • Mass Media • Arrow • Move Out • Wanderers • Riverside Gardenhttps://digitalcommons.ursinus.edu/lantern/1182/thumbnail.jp

    The fate of received sperm in the reproductive tract of a hermaphroditic snail and its implications for fertilisation.

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    Multiple mating, sperm storage and internal fertilisation enhance sperm competition. The great pond snail can use stored sperm for over three months, and frequently mates with different partners. This hermaphrodite, Lymnaea stagnalis, can also self-fertilise and often produces egg masses containing both selfed and outcrossed eggs. Hence, a sperm recipient may exert considerable control over paternity. Using microsatellite markers, we show that when allosperm are present, all genotyped eggs are cross-fertilised. We also find that sperm have the opportunity to compete, because double matings lead on average to equal paternity for each sperm donor. This indicates that received sperm are randomly mixed in storage. To gain further insight into the mechanisms underlying the process of sperm storage, digestion and utilisation, we investigated the fate of donated sperm at different times after copulation. We find that within 3 h after transfer most sperm have been transported into the sperm-digesting organ. Fluorescent labelling of sperm in histological sections further reveals that allosperm are not stored in the fertilisation pouch, but upstream in either the hermaphroditic duct, seminal vesicles, or ovotestis. Besides contributing to the understanding of the mechanisms underlying sperm competition and/or cryptic sperm choice, this study shows that mixed mating cannot be treated as a separate issue in hermaphroditic animals. © Springer Science+Business Media B.V. 2008

    The language(s) of comedy

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    Code for Attaching SF tips to LF backbone, and input code

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    The code in BindingSFandLF.R file copies mammal family branching pattern from SF phylogeny (Bininda-Emonds et al. 2007) and attaches it on the corresponding branch in the LF phylogeny (Meredith et al. 2011).<br><br>The two .in files are input files for BayesTraits analyses.<div><br></div><div>SUMMARY.R processes BayesTraits posteriors</div
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