10,329 research outputs found

    The Genome and Methylome of a Subsocial Small Carpenter Bee, Ceratina calcarata

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    Understanding the evolution of animal societies, considered to be a major transition in evolution, is a key topic in evolutionary biology. Recently, new gateways for understanding social evolution have opened up due to advances in genomics, allowing for unprecedented opportunities in studying social behavior on a molecular level. In particular, highly eusocial insect species (caste-containing societies with nonreproductives that care for siblings) have taken center stage in studies of the molecular evolution of sociality. Despite advances in genomic studies of both solitary and eusocial insects, we still lack genomic resources for early insect societies. To study the genetic basis of social traits requires comparison of genomes from a diversity of organisms ranging from solitary to complex social forms. Here we present the genome of a subsocial bee, Ceratina calcarata. This study begins to address the types of genomic changes associated with the earliest origins of simple sociality using the small carpenter bee. Genes associated with lipid transport and DNA recombination have undergone positive selection in C. calcarata relative to other bee lineages. Furthermore, we provide the first methylome of a noneusocial bee. Ceratina calcarata contains the complete enzymatic toolkit for DNA methylation. As in the honey bee and many other holometabolous insects, DNA methylation is targeted to exons. The addition of this genome allows for new lines of research into the genetic and epigenetic precursors to complex social behaviors

    Social Evolution: New Horizons

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    Cooperation is a widespread natural phenomenon yet current evolutionary thinking is dominated by the paradigm of selfish competition. Recent advanced in many fronts of Biology and Non-linear Physics are helping to bring cooperation to its proper place. In this contribution, the most important controversies and open research avenues in the field of social evolution are reviewed. It is argued that a novel theory of social evolution must integrate the concepts of the science of Complex Systems with those of the Darwinian tradition. Current gene-centric approaches should be reviewed and com- plemented with evidence from multilevel phenomena (group selection), the constrains given by the non-linear nature of biological dynamical systems and the emergent nature of dissipative phenomena.Comment: 16 pages 5 figures, chapter in forthcoming open access book "Frontiers in Ecology, Evolution and Complexity" CopIt-arXives 2014, Mexic

    Decision making during the scouting behaviour of the slave-making ant Protomognathus americanus

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    Colony size predicts division of labour in Attine ants

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    Division of labour is central to the ecological success of eusocial insects, yet the evolutionary factors driving increases in complexity in division of labour are little known. The size–complexity hypothesis proposes that, as larger colonies evolve, both non-reproductive and reproductive division of labour become more complex as workers and queens act to maximize inclusive fitness. Using a statistically robust phylogenetic comparative analysis of social and environmental traits of species within the ant tribe Attini, we show that colony size is positively related to both non-reproductive (worker size variation) and reproductive (queen–worker dimorphism) division of labour. The results also suggested that colony size acts on non-reproductive and reproductive division of labour in different ways. Environmental factors, including measures of variation in temperature and precipitation, had no significant effects on any division of labour measure or colony size. Overall, these results support the size–complexity hypothesis for the evolution of social complexity and division of labour in eusocial insects. Determining the evolutionary drivers of colony size may help contribute to our understanding of the evolution of social complexity

    Colony size predicts division of labour in Attine ants

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    Division of labour is central to the ecological success of eusocial insects, yet the evolutionary factors driving increases in complexity in division of labour are little known. The size–complexity hypothesis proposes that, as larger colonies evolve, both non-reproductive and reproductive division of labour become more complex as workers and queens act to maximize inclusive fitness. Using a statistically robust phylogenetic comparative analysis of social and environmental traits of species within the ant tribe Attini, we show that colony size is positively related to both non-reproductive (worker size variation) and reproductive (queen–worker dimorphism) division of labour. The results also suggested that colony size acts on non-reproductive and reproductive division of labour in different ways. Environmental factors, including measures of variation in temperature and precipitation, had no significant effects on any division of labour measure or colony size. Overall, these results support the size–complexity hypothesis for the evolution of social complexity and division of labour in eusocial insects. Determining the evolutionary drivers of colony size may help contribute to our understanding of the evolution of social complexity

    Division of labour and risk taking in the dinosaur ant, Dinoponera quadriceps

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    The success of social insects can be largely attributed to division of labour. In contrast to most social insects, many species with simple societies contain workers which are capable of sexual reproduction. Headed by one or a few reproductive individuals, subordinate workers form a dominance hierarchy, queuing to attain the reproductive role. In these species task allocation may be influenced by individual choice based on future reproductive prospects. Individuals with a better chance of inheriting the colony may be less likely to take risks and high-ranking workers that spend a greater amount of time in proximity to the brood may be able to increase the ability to police egg-laying by cheating subordinates. We investigated division of labour and risk taking in relation to dominance rank in the queenless ponerine ant, Dinoponera quadriceps, a species with relatively simple societies. Using behavioural observations, we show that high-ranking workers spend more time performing egg care, less time foraging and are less likely to defend the nest against attack. High-rankers also spent a greater amount of time guarding and inspecting eggs, behaviours which are likely to improve detection of egg laying by cheating subordinates. We also show that high-ranking workers spend a greater amount of time idle, which may help increase lifespan by reducing energy expenditure. Our results suggest that both risk-taking and egg-care behaviours are related to future reproductive prospects in D. quadriceps. This highlights a mechanism by which effective division of labour could have been achieved during the early stages of eusocial evolution

    Life Beneath Silk Walls: A Review of the Primitively Social Embiidina

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    I review and summarize the scattered information on embiids (Order Embiidina), with an emphasis on details of colony structure and maternal care. I summarize experimental and observational field results from a detailed study on parental and communal behavior of Antipaluria urichi, a Trinidadian webspinner. Topics discussed include the function of maternal behavior, interactions with egg parasitoids, antipredator attributes of communal living, and possible functions of silk. I also compare features of webspinner sociality to other communal insects and spiders. In addition, I discuss promising topics for future study, including male dimorphism, the possibility of higher sociality, and communication systems

    Biological altruism, eusociality and the superorganism: a critical analysis of the role of biological altruism within eusociality research.

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    232 p.In this thesis I critically assess the role of the concept of biological altruism (BA) within eusociality research by assessing the following questions: 1) Is the concept of BA a correct description of the behaviour of the non-reproductive castes in eusocial insect colonies? 2) Has the widespread use of the concept of BA been problematic for eusociality research? I argue that, not only is the concept of BA unlikely to be the correct description of the behaviour of the non-reproductive castes, but the widespread use of the concept of BA has been problematic for the field. The mainstream focus on BA led to viable alternatives, e.g. parental manipulation, superorganism, etc., receiving much less attention by researchers. However, current evidence supports the view that parental manipulation, but not BA, was the likely cause of the evolution of the non-reproductive castes. Furthermore, I develop a novel organizational approach to the superorganism and argue that colonies of the most complex eusocial insects, e.g. honey bees, are biological individuals in their own right, and thus BA is not applicable to the individual insects in those colonies

    Biological altruism, eusociality and the superorganism: a critical analysis of the role of biological altruism within eusociality research.

    Get PDF
    232 p.In this thesis I critically assess the role of the concept of biological altruism (BA) within eusociality research by assessing the following questions: 1) Is the concept of BA a correct description of the behaviour of the non-reproductive castes in eusocial insect colonies? 2) Has the widespread use of the concept of BA been problematic for eusociality research? I argue that, not only is the concept of BA unlikely to be the correct description of the behaviour of the non-reproductive castes, but the widespread use of the concept of BA has been problematic for the field. The mainstream focus on BA led to viable alternatives, e.g. parental manipulation, superorganism, etc., receiving much less attention by researchers. However, current evidence supports the view that parental manipulation, but not BA, was the likely cause of the evolution of the non-reproductive castes. Furthermore, I develop a novel organizational approach to the superorganism and argue that colonies of the most complex eusocial insects, e.g. honey bees, are biological individuals in their own right, and thus BA is not applicable to the individual insects in those colonies
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