02439nas a2200217   4500008004100000245014600041210006900187300001400256490000700270520159300277653003101870653002401901653002201925653002101947653003001968653002301998653001502021100002402036700002302060856013802083       2005                        eng d00aThe evolution of male genitalia: patterns of genetic variation and covariation in the genital sclerites of the dung beetle Onthophagus taurus0 aevolution of male genitalia patterns of genetic variation and co  a1281-12920 v183 aThree main hypotheses, have been invoked to explain divergent genital evolution, the lock and key, pleiotropy, and sexual selection hypotheses, each of which make different predictions about how genital traits are inherited. Here we used a half-sib breeding design to examine the patterns of genetic variation and covariation between male genital sclerites, and their covariance with general body morphology in the dung beetle Onthophagus taurus. We found CVA’s and CVP’s were similar for both genital and general morphological traits and that CVR’s were large for both trait types. We found that male genital sclerites were negatively genetically correlated with general morphological traits. Variation in male genital morphology has direct implications for a male’s fertilization success and the resulting sexual selection acting on male genitalia is predicted to maintain high levels of additive genetic variance. Contrary to this prediction, we found that individual genital sclerites all had low levels of additive genetic variance and large maternal and environmental sources of variation. Our data suggest that the genital sclerites in O. taurus are not inherited independently but as a genetically integrated unit. More import- antly, the way the different sclerites function to influence male fertilization success reflects this genetic integration. Even though levels of VA in individual genital sclerites may be low, there may still be sufficient VA in multivariate trait space for selection to generate evolutionary change in the overall morphology of male genitalia. 10aadditive genetic variation10agenetic correlation10agenital evolution10amaternal effects10amorphological integration10aOnthophagus taurus10apleiotropy1 aHouse, Clarissa, M.1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/evolution-male-genitalia-patterns-genetic-variation-and-covariation-genital-sclerites-dung-beetle-on01741nas a2200193   4500008004100000245011700041210006900158300001200227490000700239520101400246653001901260653001901279653001901298653002301317653002201340100002401362700002301386856013801409       2006                        eng d00aOffensive and defensive sperm competition roles in the dung beetle Onthophagus taurus (Coleoptera: Scarabaeidea)0 aOffensive and defensive sperm competition roles in the dung beet  a131-1360 v603 aSperm competition is predicted to generate op- posing selection pressures on males. On one hand, selec- tion should favour ‘defensive’ adaptations that protect a male’s ejaculate from displacement, while, on the other hand, selection should favour ‘offensive’ adaptations that overcome paternity assurance mechanisms of rivals. Here, we use the sterile male technique to assess sperm pre- cedence when a male dung beetle Onthophagus taurus mates in both a defensive (first male) and an offensive (second male) role. Significant variation in a male’s sperm precedence (both P1 and P2) was detected, and an individual’s defensive (P1) and offensive (P2) abilities were positively correlated. Thus, it appears that sexual selection simultaneously selects for ‘defensive’ and ‘of- fensive’ adaptations in O. taurus. We discuss a variety of male traits in O. taurus that potentially contribute to a male’s ability to be successful whenmatinginan‘of-fensive’ and a ‘defensive’ role. 10aDefensive role10amale genitalia10aOffensive role10aOnthophagus taurus10aSperm competition1 aHouse, Clarissa, M.1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/offensive-and-defensive-sperm-competition-roles-dung-beetle-onthophagus-taurus-coleoptera-scarabaeid00732nas a2200193   4500008004100000245011900041210006900160260000800229300001200237490000700249653001700256653002600273653002200299653002300321653002100344100001500365700002300380856013500403       1997                        eng d00aPatterns of fluctuating asymmetry in beetle horns: an experimental examination of the honest signalling hypothesis0 aPatterns of fluctuating asymmetry in beetle horns an experimenta  cmay  a109-1140 v4110abeetle horns10afluctuating asymmetry10ahonest signalling10aOnthophagus taurus10asexual selection1 aHunt, John1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/patterns-fluctuating-asymmetry-beetle-horns-experimental-examination-honest-signalling-hypothesis02368nas a2200181   4500008004100000245016000041210006900201300001200270490000700282520162100289653003101910653002801941653002301969653001801992100001502010700002302025856013802048       2002                        eng d00aConfidence of paternity and paternal care: covariation revealed through the experimental manipulation of the mating system in the beetle Onthophagus taurus0 aConfidence of paternity and paternal care covariation revealed t  a784-7950 v153 aTheoretical models of paternal care predict that facultative reductions in male care may occur under certain conditions. One important parameter that has been shown to influence the outcome of these models is a male’s confidence of paternity. In this study, we tested whether the amount of care provided by horned males in the dimorphic beetle, Onthophagus taurus, varied with his confidence of paternity. Male care results in an increased weight of dung provided in the brood masses produced by the pair. Using the sterile male technique we showed that a horned male’s paternity declined with the number of sneak males in the population. The relationship was nonlinear, with paternity declining most rapidly between a frequency of one and three sneaks, and stabilizing thereafter at about 50%. A horned male’s paternity was directly related to the number of copulations with the female, relative to the number of copulations achieved by sneaks. Horned males were shown to reduce their care in relation to their declining paternity. Video analysis demonstrated that reductions in male care occurred through a combination of male desertion and a trade-off between caring and paternity assurance behaviours. The number of fights with sneak males was negatively related to the amount of care provided by a horned male. These results suggest that by gauging his expected paternity through the number of fights with sneaks, a horned male is able to assess his paternity and reduce his investment accordingly. Our data thus provide strong empirical support for the proposed link between paternity and paternal care. 10aalternative mating tactics10aconfidence of paternity10aOnthophagus taurus10apaternal care1 aHunt, John1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/confidence-paternity-and-paternal-care-covariation-revealed-through-experimental-manipulation-mating03021nas a2200205   4500008004100000245007100041210006900112300001200181490000700193520235800200653002002558653002302578653003402601653001802635653002102653653000702674100001502681700002302696856009602719       2004                        eng d00aOptimal maternal investment in the dung beetle Onthophagus taurus?0 aOptimal maternal investment in the dung beetle Onthophagus tauru  a302-3120 v553 aOptimal investment theory is based on the assumption that the proximate constraint acting on parental investment is resource based. A trade-off between per offspring investment and total investment seems intuitive. Consequently, a parent’s investment strategy is expected to represent a trade-off between the benefits of investment for current offspring and the costs to future reproduction for parents. In this study, we provide clear evidence that the costs and benefits of maternal provisioning in the dung beetle Onthophagus taurus influence the amount of provisions provided by the mother. Horse dung is typically of a higher nutritional value than cow dung and females were shown to provide 20% less dung to offspring when provisioning with horse dung. By reducing their investment per offspring and exhibiting a clear preference to provision offspring with horse dung, females were able to produce significantly more offspring. Females provisioning with horse dung received greater fitness returns per unit of investment and experienced lower provisioning costs, in terms of the minimum amount of dung required to produce a surviving offspring, than females provisioning with cow dung. Females provisioning in soil of low moisture content were found to have higher tunneling costs than those provi- sioning in soil of high moisture content, while the fitness returns per unit of investment did not differ. We adopted a marginal value theorem (MVT) approach to calculate the theoretical optimal level of investment for each dung type and for each soil moisture. Predicted levels of provision- ing were lower for horse dung than for cow dung and for moist soil than for dry soil. Therefore, the results of this study are in qualitative agreement with MVT predictions and provide empirical support for the proposal that females can adaptively adjust their level of investment in response to resource and/or habitat quality. However, the theoretically predicted optimal investment yielded a poor quantitative fit with our observed levels of investment, with females providing over twice the investment predicted by the MVT approach. We suggest that this difference may reflect either our inability in directly quantifying all the necessary costs and benefits of investment in O. taurus and/or the applicability of the underlying assumptions of MVT.10aHabitat quality10aOnthophagus taurus10aOptimal investment strategies10aParental care10aResource quality10a·1 aHunt, John1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/optimal-maternal-investment-dung-beetle-onthophagus-taurus02417nas a2200301   4500008004100000245006700041210006400108300001000172490000700182520151100189653002301700653001501723653001601738653002801754653002601782653002701808653002701835653002301862653001301885653001801898653002201916653002401938653001301962100001301975700002001988700002002008856008702028       2002                        eng d00aA cost of maternal care in the dung beetle Onthophagus taurus?0 acost of maternal care in the dung beetle Onthophagus taurus  a57-640 v153 aParental care theory assumes that investment in current offspring will trade against future investment. A number of field studies on birds have used clutch size manipulations to demonstrate a survival cost to chick rearing. However, such studies do not account for costs accrued during earlier stages of reproduction because not all aspects of reproductive effort are manipulated by varying the number of nestlings. in this study, we investigate the effect of reproductive effort on female survival in the dung beetle, Onthophagus taurus. By experimentally manipulating mating status and dung availability, we demonstrate that virgin females survive longer than mated females and that the survival of mated females was negatively associated with the number of brood masses produced. Using a novel manipulation of the mating system, we separated the effects of egg production and maternal care on female survival. Previously, we have shown that females provisioning with the assistance of a major male provide relatively less care than unassisted females. However, paternal assistance did not alter the number of brood masses produced and hence the amount of reproductive effort that was allocated to egg production. Therefore, our finding, that female survival was increased when receiving paternal assistance provides, to our knowledge, the first definitive evidence that maternal care reduces female lifespan. These results are of major importance to theoretical models on the evolution of parental care.10aBREEDING BLUE TITS10aBROOD-SIZE10aCLUTCH-SIZE10adrosophila-melanogaster10afluctuating asymmetry10aLIFE-HISTORY EVOLUTION10alife-history trade-off10aOnthophagus taurus10aPARENTAL10aParental care10areproductive cost10areproductive effort10aSURVIVAL1 aHunt, J.1 aSimmons, L., W.1 aKotiaho, J., S.  uhttps://scarabnet.myspecies.info/cost-maternal-care-dung-beetle-onthophagus-taurus