Search results for "Onthophagus"
showing 9 items of 9 documents
A link between heritable parasite resistance and mate choice in dung beetles
2019
AbstractParasites play a central role in the adaptiveness of sexual reproduction. Sexual selection theory suggests a role for parasite resistance in the context of mate choice, but the evidence is mixed. The parasite-mediated sexual selection (PMSS) hypothesis derives a number of predictions, among which that resistance to parasites is heritable, and that female choice favors parasite resistance genes in males. Here, we tested the PMSS hypothesis using the dung beetle Onthophagus taurus, a species that can be heavily parasitized by Macrocheles merdarius mites, which are known to affect adult survival. We investigated the heritability of resistance to M. merdarius, as well as whether female …
A cost of maternal care in the dung beetle Onthophagus taurus?
2002
Parental 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 o…
Major Differences in Minor Allometries: A Reply to Moczek.
2018
Abstract: By comparing alternative measurements of horn length in the beetle Onthophagus taurus, we have investigated why scaling patterns differ between laboratories. We show that some measurements are confounded by including part of the head in the horn size measurement and consistently underestimate the allometry of horns in minor males. Our data show how linear measures that avoid confounding horn length with head size produce scaling patterns that support a positive allometry rather than a reprogramming model of horn growth. We also found horn volume was highly positively allometric this estimate of growth therefore further supports a positive allometry model.
Data from: A link between heritable parasite resistance and mate choice in dung beetles
2019
Parasites play a central role in the adaptiveness of sexual reproduction. Sexual selection theory suggests a role for parasite resistance in the context of mate choice, but the evidence is mixed. The parasite-mediated sexual selection (PMSS) hypothesis derives a number of predictions, among which that resistance to parasites is heritable, and that female choice favours parasite resistance genes in males. Here we tested the PMSS hypothesis using the dung beetle Onthophagus taurus, a species that can be heavily parasitised by Macrocheles merdarius mites, which are known to affect adult survival. We investigated the heritability of resistance to M. merdarius, as well as whether female O. tauru…
Males influence maternal effects that promote sexual selection: a quantitative genetic experiment with dung beetles Onthophagus taurus
2003
J.S.K. was funded by the Academy of Finland, L.W.S. by the Australian Research Council, J.H. by an Australian Postgraduate Award, and J.L.T. by a postdoctoral research fellowship from the University of Western Australia. Recently, doubt has been cast on studies supporting good genes sexual selection by the suggestion that observed genetic benefits for offspring may be confounded by differential maternal allocation. In traditional analyses, observed genetic sire effects on offspring phenotype may result from females allocating more resources to the offspring of attractive males. However, maternal effects such as differential allocation may represent a mechanism promoting genetic sire effects…
Towards a resolution of the lek paradox
2001
Genetic benefits in the shape of 'good genes' have been invoked to explain costly female choice in the absence of direct fitness benefits. Little genetic variance in fitness traits is expected, however, because directional selection tends to drive beneficial alleles to fixation. There seems to be little potential, therefore, for female choice to result in genetic benefits, giving rise to the 'lek paradox'. Nevertheless, evidence shows that genetic variance persists despite directional selection and genetic benefits of female choice are frequently reported. A theoretical solution to the lek paradox has been proposed on the basis of two assumptions: that traits are condition-dependent, and th…
Intralocus tactical conflict: Genetic correlations between fighters and sneakers of the dung beetle Onthophagus taurus
2015
Males and females differ in their phenotypic optima for many traits, and as the majority of genes are expressed in both sexes, some alleles can be beneficial to one sex but harmful to the other (intralocus sexual conflict; ISC). ISC theory has recently been extended to intrasexual dimorphisms, where certain alleles may have opposite effects on the fitness of males of different morphs that employ alternative reproductive tactics (intralocus tactical conflict; ITC). Here, we use a half-sib breeding design to investigate the genetic basis for ISC and ITC in the dung beetle Onthophagus taurus. We found positive heritabilities and intersexual genetic correlations for almost all traits investigat…
Matters of scale: positive allometry and the evolution of male dimorphisms
2005
J.L.T. was funded by a Biotechnology and Biological Sciences Research Council research fellowship, J.S.K. by the Academy of Finland, and N.R.L. by a Natural Environment Research Council research fellowship. The developmental independence of alternative phenotypes is key to evolutionary theories of phenotypic plasticity and the origins of diversity. Male dimorphisms associated with alternative reproductive tactics are widely cited examples of such facultative expression of divergent fitness optima. Current models for the evolution of male dimorphisms invoke a size-dependent threshold at which the phenotype is reprogrammed. We use predictions derived from allometric modeling to test for the e…
Data from: Intralocus tactical conflict: genetic correlations between fighters and sneakers of the dung beetle Onthophagus taurus
2015
Males and females differ in their phenotypic optima for many traits, and since the majority of genes are expressed in both sexes, some alleles can be beneficial to one sex but harmful to the other (intralocus sexual conflict; ISC). ISC theory has recently been extended to intrasexual dimorphisms, where certain alleles may have opposite effects on the fitness of males of different morphs that employ alternative reproductive tactics (intralocus tactical conflict; ITC). Here we use a half-sib breeding design to investigate the genetic basis for ISC and ITC in the dung beetle Onthophagus taurus. We found positive heritabilities and intersexual genetic correlations for almost all traits investig…