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David N. Reznick - One of the best experts on this subject based on the ideXlab platform.
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comparative life histories of fishes in the subgenus limia pisces poeciliidae
Journal of Fish Biology, 2015Co-Authors: S N Cohen, John U Regus, Y Reynoso, T Mastro, David N. ReznickAbstract:This study presents life-history descriptions for 12 species in the subgenus Limia, which are endemic to the Greater Antilles. All species in this study lack evidence of superfoetation, producing a single brood of offspring before developing subsequent broods. Interbrood intervals (number of days between parturition events) are also consistent with intervals of species that lack superfoetation. Maternal provisioning, characterized by matrotrophy index, is <1.0 for all species of Limia. This is consistent with species that provide little or no maternal provisioning to developing embryos after ovum fertilization (lecithotrophic). Four species exhibit potentially bi-modal size distributions of mature males. Work on other poeciliids suggests that such bimodal distributions can be caused by genetic polymorphisms in some species. Principle component analyses revealed an axis of interspecific variation in life histories that separated species with small size at maturity and the production of many, small offspring from those with large size at maturity and that produce few, large offspring. This pattern of life-history diversity occurs in many other groups of organisms.
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why do placentas evolve an evaluation of the life history facilitation hypothesis in the fish genus poeciliopsis
Functional Ecology, 2011Co-Authors: Marcelo N. Pires, John U Regus, Ronald D Bassar, Kevin E Mcbride, Theodore Garland, David N. ReznickAbstract:Summary 1. The Northern Clade of the fish genus Poeciliopsis includes six closely related species, three of which lack placentas and three that have placentas but vary in the extent of post-fertilization provisioning. 2. We used this diversity to evaluate a series of hypotheses proposed in earlier publications concerning why the placenta has evolved. All hypotheses share the attribute of arguing that the placenta evolved to enhance the evolution of some other life-history trait, such as to reduce the age at maturation or to increase offspring size. We refer to these hypotheses collectively as ‘life-history facilitation hypotheses’. 3. A general way to evaluate the plausibility of such proposals is to ask whether the evolution of the placenta is predictably associated with the evolution of other components of the life history. 4. We evaluated such associations in two ways. First, we performed a multivariate analysis of life-history data for fish collected and preserved in nature. This analysis included 16 populations across all six species. Secondly, we performed a more complete quantification of the life histories of the laboratory descendents from five populations representing four species, then performed a similar multivariate analysis. The laboratory study added information about the timing of reproduction (age at maturity, frequency of reproduction). 5. Both analyses yielded similar results, which were that the evolution of increased placentation is correlated with the evolution of a smaller size at first reproduction, the production of fewer and smaller offspring per litter, but an increase in the number of litters that were developing simultaneously in the ovary (Superfetation). Increased placentation is associated with progressively earlier ages at maturation and shorter intervals between the birth of successive litters of offspring. Overall, increased placentation was associated with an increase in the rate of production of offspring early in life. A peculiar attribute of placentation is that this increase in the rate of offspring production can be attained despite a simultaneous reduction in the proportional quantity of resources devoted to reproduction. 6. These trends support one of the life history facilitation hypotheses, which is that placentation facilitates earlier maturity and a higher rate of reproduction early in life. They also suggest a possible connection between the evolution of the placenta and the well-established theory of life-history evolution, since these same life history attributes are predicted to evolve in response to exposure to high extrinsic rates of adult mortality.
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Molecular phylogenetic relationships and the coevolution of placentotrophy and Superfetation in Poecilia (Poeciliidae: Cyprinodontiformes).
Molecular phylogenetics and evolution, 2011Co-Authors: Robert W. Meredith, David N. Reznick, Marcelo N. Pires, Mark S. SpringerAbstract:Members of Poeciliidae are used as model organisms for experimental studies on natural and sexual selection, and comparative studies of life-history evolution. The latter have demonstrated multiple origins of both Superfetation and placentotrophy within Poeciliidae. Most recently, placentotrophy has been described in five species of Poecilia (Pamphorichthys), but only one of these (P. hasemani) shows evidence of Superfetation. Here, we use a molecular phylogeny based on concatenated nuclear and mitochondrial gene sequences to test hypotheses of correlated evolution between Superfetation and placentotrophy in Poecilia. Taxon sampling included all species in the subgenera Micropoecilia and Pamphorichthys for which the presence or absence of placentotrophy and Superfetation have been determined, as well as representatives of all other Poecilia subgenera (Acanthophacelus, Limia, Mollienesia, Poecilia, Pseudolimia). Phylogenetic analyses were performed with maximum parsimony, maximum likelihood, and Bayesian methods; ancestral states for life-history characters were reconstructed with parsimony and SIMMAP; correlation analyses were performed with SIMMAP; and divergence times were estimated using a relaxed molecular clock. All subgenera in Poecilia were recovered as monophyletic. The basal split in Poecilia is between P. (Acanthophacelus )+ P .( Micropoecilia) and the other five subgenera. In the latter clade, P .( Poecilia) is the sister-group to the remaining four subgenera. Within P. (Pamphorichthys), all analyses with the combined data set recovered P. (Pamphorichthys) araguaiensis as the sister taxon to P .( Pamphorichthys) hollandi, and P .( Pamphorichthys) scalpridens as the sister taxon to P .( Pamphorichthys) minor. P .( Pamphorichthys) hasemani was either the sister taxon to P .( Pamphorichthys) hollandi + P .( Pamphorichthys) minor (maximum likelihood, Bayesian) or the sister taxon to all other Pamphorichthys species (maximum parsimony). Ancestral state reconstructions suggest that placentotrophy and Superfetation evolved on the same branch in P .( Micropoecilia), whereas placentotrophy evolved before Superfetation in P .( Pamphorichthys). SIMMAP analyses indicate a statistically significant association between placentotrophy and Superfetation. Within P. (Micropoecilia) both placentotrophy and Superfetation evolved in 64 million years. Within P .( Pamphorichthys), Superfetation evolved in 69 million years on the P .( Pamphorichthys) hasemani branch, and placentotrophy evolved in 610 million years in the common ancestor of this subgenus.
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the evolution of placentas and Superfetation in the fish genus poecilia cyprinodontiformes poeciliidae subgenera micropoecilia and acanthophacelus
Biological Journal of The Linnean Society, 2010Co-Authors: Marcelo N. Pires, Jeff Arendt, David N. ReznickAbstract:Complex adaptations are often found in nature, although our ability to discern how and why such traits evolved is limited because their origin occurred in the distant past and the details of their evolution have been lost through extinction (e.g. all placental mammals inherited their placentas from a single common ancestor that lived over 100 Mya). In poeciliid fishes, placentas have evolved independently multiple times and portions of the path to the evolution of complexity can be found in living species. In the present study, we describe the life histories of six species within the genus Poecilia that includes the subgenera Micropoecilia and Acanthophacelus (the guppy; Poecilia reticulata). We demonstrate that extensive placentotrophy and Superfetation, the ability to simultaneously carry more than one developing brood, have evolved within this clade. These fish represent the third clade in which we have discovered the independent origin of a placenta that also includes close relatives that lack a placenta. We discuss possible adaptive advantages of the joint evolution of extensive placentation and Superfetation in these fishes. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 784–796.
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Pre- and post-fertilization maternal provisioning in livebearing fish species and their hybrids (Poeciliidae: Poeciliopsis)
Functional Ecology, 2008Co-Authors: Martin M. Turcotte, Marcelo N. Pires, R. C. Vrijenhoek, David N. ReznickAbstract:Summary 1. Viviparous organisms vary greatly in their level of post-fertilization maternal provisioning and extensive provisioning (including very complex placentas) has evolved dozens of times in vertebrates. Through the use of species representing transitional states we aim to explore and develop empirically supported hypotheses that explain how such a complex trait has evolved. 2. In this study, we investigated the life histories and patterns of post-fertilization maternal provisioning in naturally occurring, all-female, hybrids between Poeciliopsis monacha , a viviparous species that produces large eggs and nourishes its embryos via stored yolk (lecithotrophy) and P. lucida , which produces small eggs and nourishes its embryos after fertilization via a follicular placenta (matrotrophy). Hybrids can be diploid or triploid, leading to different levels of gene dosage from the parental species. 3. We found that the extent of Superfetation and average brood size of the hybrids did not differ significantly from their sexual parental species even though the latter was much lower in the hybrids. Moreover, the allodiploid, P. monacha-lucida , has intermediate sized eggs, whereas the allotriploid, P. monacha-monacha-lucida , produces eggs of similar size to those of P. monacha . The degree of post-fertilization maternal provisioning was unrelated to genomic dosages, with wild-caught hybrids being lecithotrophic, as seen in the maternal species ( P. monacha ). 4. Our results with naturally occurring P. monacha-lucida hybrids differed from those obtained with laboratory-synthesized hybrid clones, which were either lecithotrophic or weakly matrotrophic. Consequently, we propose two non-mutually exclusive hypotheses to explain why lecithotrophic clones might be favoured in the wild. One hypothesis suggests that lecithotrophic hybrids minimize competition with the matrotrophic paternal sexual species from which they require sperm to reproduce. Alternatively, we propose that natural selection has eliminated matrotrophic hybrids that suffer from intergenomic conflict in the degree of post-fertilization maternal provisioning. 5. We have thus identified an empirical system and developed testable hypotheses that will help elucidate the selective pressures that caused the evolution of post-fertilization maternal provisioning and potentially provide an opportunity to explore how epigenetic factors (e.g., intergenomic conflict) might influence this complex trait.
David W Macdonald - One of the best experts on this subject based on the ideXlab platform.
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FEMALE RECEPTIVITY, EMBRYONIC DIAPAUSE, AND Superfetation IN THE EUROPEAN BADGER (MELES MELES): IMPLICATIONS FOR THE REPRODUCTIVE TACTICS OF MALES AND FEMALES
2015Co-Authors: Nobuyuki Yamaguchi, Hannah L Dugdale, David W MacdonaldAbstract:The European badger Meles meles is thought to mate throughout the year, with two mating peaks occurring in late winter/spring and summer/autumn. After mating, fertilized ova enter embryonic diapause (delayed implantation) at the blastocyst stage, which lasts up to eleven months. Even if mating is successful, however, the estrous cycle may continue during embryonic diapause, which sug-gests that female badgers are capable of Superfetation (conception during pregnancy). This may increase female fitness by facilitating polyandry, and reduce the risk of infanticide by resident males through paternity confusion. Detailed understanding of female receptivity, specifically the association of super-fetation with embryonic diapause, may explain field observations of seemingly inconsistent reproductive 34 Volume 81THE QUARTERLY REVIEW OF BIOLOGY tactics of male badgers with regard to, for instance, whether or not they guard mates or defend territories. The combination of embryonic diapause and Superfetation may occur in other mustelids; if so, the sociobiology of mustelids will need re-evaluating, and the Mustelidae may prove to be a good model taxon for studies of sexual conflict in the reproduction of eutherian mammals. NATURAL SELECTION and sexual se-lection act on both sexes. However, em
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neighbouring group composition and within group relatedness drive extra group paternity rate in the european badger meles meles
Journal of Evolutionary Biology, 2014Co-Authors: Christina D Buesching, Chris Newman, Hannah L Dugdale, Geetha Annavi, Terry Burke, David W MacdonaldAbstract:Extra-group paternity (EGP) occurs commonly among group-living mammals and plays an important role in mating systems and the dynamics of sexual selection; however, socio-ecological and genetic correlates of EGP have been underexplored. We use 23 years of demographic and genetic data from a high-density European badger (Meles meles) population, to investigate the relationship between the rate of EGP in litters and mate availability, mate incompatibility and mate quality (heterozygosity). Relatedness between within-group assigned mothers and candidate fathers had a negative quadratic effect on EGP, whereas the number of neighbouring-group candidate fathers had a linear positive effect. We detected no effect of mean or maximum heterozygosity of within-group candidate fathers on EGP. Consequently, EGP was associated primarily with mate availability, subject to within-group genetic effects, potentially to mitigate mate incompatibility and inbreeding. In badgers, cryptic female choice, facilitated by superfecundation, superfoetation and delayed implantation, prevents males from monopolizing within-group females. This resonates with a meta-analysis in group-living mammals, which proposed that higher rates of EGP occur when within-group males cannot monopolize within-group females. In contrast to the positive meta-analytic association, however, we found that EGP associated negatively with the number of within-group assigned mothers and the number of within-group candidate fathers; potentially a strategy to counter within-group males committing infanticide. The relationship between the rate of EGP and socio-ecological or genetic factors can therefore be intricate, and the potential for cryptic female choice must be accounted for in comparative studies.
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Female receptivity, embryonic diapause, and Superfetation in the European badger (Meles meles): implications for the reproductive tactics of males and females.
The Quarterly review of biology, 2006Co-Authors: Nobuyuki Yamaguchi, Hannah L Dugdale, David W MacdonaldAbstract:ABSTRACT The European badger Meles meles is thought to mate throughout the year, with two mating peaks occurring in late winter/spring and summer/autumn. After mating, fertilized ova enter embryonic diapause (delayed implantation) at the blastocyst stage, which lasts up to eleven months. Even if mating is successful, however, the estrous cycle may continue during embryonic diapause, which suggests that female badgers are capable of Superfetation (conception during pregnancy). This may increase female fitness by facilitating polyandry, and reduce the risk of infanticide by resident males through paternity confusion. Detailed understanding of female receptivity, specifically the association of Superfetation with embryonic diapause, may explain field observations of seemingly inconsistent reproductive tactics of male badgers with regard to, for instance, whether or not they guard mates or defend territories. The combination of embryonic diapause and Superfetation may occur in other mustelids; if so, the soci...
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multiple paternity and reproductive tactics of free ranging american minks mustela vison
Journal of Mammalogy, 2004Co-Authors: Nobuyuki Yamaguchi, Ronald J Sarno, Warren E Johnson, Stephen J Obrien, David W MacdonaldAbstract:Demography and spatial patterns of free-ranging American mink were documented by continuous year-round trapping and radiotracking along 24 km of the River Thames in England, United Kingdom. An estimated average of 7.19 ± 0.58 SE minks per month were present between May 1995 and August 1997. Kit and juvenile paternity was assessed using 7 microsatellite markers and we observed evidence that multiple paternity occurred in this population. Although males maintained territories during most of the year, they sired litters in areas beyond their territory boundaries. We suggest that a male's inability to monopolize paternity, along with a female's ability to continue ovulation after successful matings (i.e., Superfetation) explains why males abandon territoriality during the breeding season. We suggest that the main function of a brief delayed implantation of this species may be to enable female mink to retain Superfetation, which facilitates the fertilization of ova from different ovulations by different males. This mink model, consisting of disarticulating residency from fatherhood and the possibility of Superfetation, may occur more widely among related species and requires a re-evaluation of mustelid sociobiology.
J. Jaime Zúñiga-vega - One of the best experts on this subject based on the ideXlab platform.
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What Drives Life-History Variation in the Livebearing Fish Poeciliopsis prolifica? An Assessment of Multiple Putative Selective Agents
Frontiers in Ecology and Evolution, 2021Co-Authors: Andrea J. Roth-monzón, J. Jaime Zúñiga-vega, Mark C. Belk, Jerald B. JohnsonAbstract:Life-history traits are directly linked to fitness, and therefore, can be highly adaptive. Livebearers have been used as models for understanding the evolution of life histories due to their wide diversity in these traits. Several different selective pressures, including density, predation, and resource levels, can shape life-history traits. However, these selective pressures are usually considered independently in livebearers and we lack a clear understanding of how they interact in shaping life-history evolution. Furthermore, selective pressures such as interspecific competition are rarely considered as drivers of life-history evolution in poeciliids. Here we test the simultaneous effects of several potential selective pressures on life-history traits in the livebearing fish Poeciliopsis prolifica. We employ a multi-model inference approach. We focus on four known agents of selection: resource availability, stream velocity, population density, and interspecific competition, and their effect on four life-history traits: reproductive allocation, Superfetation, number of embryos, and individual embryo size. We found that models with density and interspecific competition alone were strongly supported in our data and, hence, indicated that these two factors are the most important selective agents for most life-history traits, except for embryo size. When density and interspecific competition increase there is an increase in each of the three life-history traits (reproductive allocation, Superfetation, number of embryos). For individual embryo size, we found that all single-agent models were equivalent and it was unclear which selective agent best explained variation. We also found that models that included density and interspecific competition as direct effects were better supported than those that included them as indirect effects through their influence on resource availability. Our study underscores the importance of interspecific competitive interactions on shaping life-history traits and suggests that these interactions should be considered in future life-history studies.
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Superfetation in live-bearing fishes is not always the result of a morphological constraint
Oecologia, 2016Co-Authors: Patricia Frías-alvarez, J. Jaime Zúñiga-vegaAbstract:Superfetation is an unusual reproductive strategy that consists of the presence of multiple broods at different developmental stages within a single female. One hypothesis that was proposed to explain its adaptive significance suggests that, in fishes, Superfetation is a response to selective pressures that promote a thin and streamlined body shape, such as high-velocity water systems. Superfetation may allow for reduction in ovary size and hence improve streamlining because superfetating females carry few large, full-term embryos at any given time. We tested this morphological constraint hypothesis using reproductive and morphological data from several populations of two viviparous fishes of the family Poeciliidae ( Poeciliopsis gracilis and Poeciliopsis infans ). We found no evidence to support the morphological constraint hypothesis. In both species the degree of Superfetation varied as a function of a complex interaction between source population and female size, and this interpopulation variation was not associated with the velocity of the water current. Contrary to what we expected, females of P. gracilis with more streamlined bodies were observed in rivers where water velocity is slow or moderate. In P. infans the velocity of the water current did not predict variation in body shape. Our results are noteworthy because a previous study which focused on a congeneric species ( Poeciliopsis turrubarensis ) demonstrated strong support for this hypothesis. However, based on our evidence we conclude that the association among increased Superfetation, streamlined morphologies, and fast-flowing environments is not a general rule and that the adaptive value of Superfetation may differ among species.
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Spatial and temporal variation in superfoetation and related life history traits of two viviparous fishes: Poeciliopsis gracilis and P. infans.
Die Naturwissenschaften, 2014Co-Authors: Patricia Frías-alvarez, Constantino Macías Garcia, Luis F. Vázquez-vega, J. Jaime Zúñiga-vegaAbstract:Superfoetation is the ability of females to simultaneously bear multiple broods of embryos at different developmental stages. Most studies on the phylogenetic distribution of superfoetation and on the factors that potentially promote superfoetation ignore variation within species. Here, we studied 11 populations of two species of viviparous fishes of the family Poeciliidae (Poeciliopsis gracilis and Poeciliopsis infans) and document wide variation in superfoetation and in three related life history traits: brood size, individual embryo mass and total reproductive allotment. We found significant differences in the average number of simultaneous broods among populations of P. gracilis but not among populations of P. infans. In addition, we found even greater variation between months within populations for both species, although no specific pattern of temporal variation was evident. Instead of the expected consistency of seasonal differences in superfoetation across populations, we found that large variation among months within seasons and the amount and direction of this monthly variation differed widely between populations. Our results emphasize the importance of including intraspecific variation in superfoetation and other life history traits in studies that aimed at finding general explanations of life history trait evolution.
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Habitat predicts reproductive Superfetation and body shape in the livebearing fish Poeciliopsis turrubarensis
Oikos, 2007Co-Authors: J. Jaime Zúñiga-vega, David N. Reznick, Jerald B. JohnsonAbstract:Superfetation, the ability of females to simultaneously carry more than one brood at different developmental stages, is an unusual reproductive strategy that has independently evolved several times in the livebearing fish family Poeciliidae. Why this strategy has evolved remains uncertain. One hypothesis is that Superfetation is a response to selective pressures that constrain the physical space within a female in which her offspring can develop. This hypothesis is reasonable, because Superfetation should reduce the total volume needed to house developing embryos - that is, fewer large, fully developed embryos will be held by a superfetating female (with several broods at different developmental stages) than a non-superfetating female (where all embryos reach a fully developed stage at the same time). In this study, we explore this 'morphological constraint' hypothesis of Superfetation by examining the livebearing fish, Poeciliopsis turrubarensis. We found that populations vary markedly in degree of Superfetation, with individuals carrying from two to four distinct broods across different geographic areas. These populations also occupy a range of habitat types: some populations occur in slow moving coastal rivers near the ocean, while other populations occur far inland in fast moving waters that drain steep mountain environments. In comparing populations from these two types of environments, we find a strong association between stream habitat type and the degree of Superfetation within populations. Fish from inland populations have higher levels of Superfetation than their coastal counterparts. In addition, geometric morphometric analysis revealed that inland populations are also more fusiform than fish from coastal locations. Combined, these two lines of evidence support the 'morphological constraint' hypothesis, and suggest that the life history strategy of Superfetation could be driven by environmental pressures that favor a more streamlined phenotype.
Nicola M. Marples - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Reproductive Biology Including Evidence for Superfetation in the European BadgerMeles meles (Carnivora: Mustelidae)
2016Co-Authors: Leigh A. L. Corner, Lynsey J. Stuart, David J. Kelly, Nicola M. MarplesAbstract:The reproductive biology of the European badger (Meles meles) is of wide interest because it is one of the few mammal species that show delayed implantation and one of only five which are suggested to show Superfetation as a reproductive strategy. This study aimed to describe the reproductive biology of female Irish badgers with a view to increasing our understanding of the process of delayed implantation and Superfetation. We carried out a detailed histological examination of the reproductive tract of 264 female badgers taken from sites across 20 of the 26 counties in the Republic of Ireland. The key results show evidence of multiple blastocysts at different stages of development present simultaneously in the same female, supporting the view that Superfetation is relatively common in this population of badgers. In addition we present strong evidence that the breeding rate in Irish badgers is limited by failure to conceive, rather than failure at any other stages of the breeding cycle. We show few effects of age on breeding success, suggesting no breeding suppression by adult females in this population. The study sheds new light on this unusual breeding strat-egy of delayed implantation and Superfetation, and highlights a number of significant differ-ences between the reproductive biology of female Irish badgers and those of Great Britain and Swedish populations
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Reproductive Biology Including Evidence for Superfetation in the European Badger Meles meles (Carnivora: Mustelidae).
PloS one, 2015Co-Authors: Leigh A. L. Corner, Lynsey J. Stuart, David J. Kelly, Nicola M. MarplesAbstract:The reproductive biology of the European badger (Meles meles) is of wide interest because it is one of the few mammal species that show delayed implantation and one of only five which are suggested to show Superfetation as a reproductive strategy. This study aimed to describe the reproductive biology of female Irish badgers with a view to increasing our understanding of the process of delayed implantation and Superfetation. We carried out a detailed histological examination of the reproductive tract of 264 female badgers taken from sites across 20 of the 26 counties in the Republic of Ireland. The key results show evidence of multiple blastocysts at different stages of development present simultaneously in the same female, supporting the view that Superfetation is relatively common in this population of badgers. In addition we present strong evidence that the breeding rate in Irish badgers is limited by failure to conceive, rather than failure at any other stages of the breeding cycle. We show few effects of age on breeding success, suggesting no breeding suppression by adult females in this population. The study sheds new light on this unusual breeding strategy of delayed implantation and Superfetation, and highlights a number of significant differences between the reproductive biology of female Irish badgers and those of Great Britain and Swedish populations.
Hannah L Dugdale - One of the best experts on this subject based on the ideXlab platform.
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FEMALE RECEPTIVITY, EMBRYONIC DIAPAUSE, AND Superfetation IN THE EUROPEAN BADGER (MELES MELES): IMPLICATIONS FOR THE REPRODUCTIVE TACTICS OF MALES AND FEMALES
2015Co-Authors: Nobuyuki Yamaguchi, Hannah L Dugdale, David W MacdonaldAbstract:The European badger Meles meles is thought to mate throughout the year, with two mating peaks occurring in late winter/spring and summer/autumn. After mating, fertilized ova enter embryonic diapause (delayed implantation) at the blastocyst stage, which lasts up to eleven months. Even if mating is successful, however, the estrous cycle may continue during embryonic diapause, which sug-gests that female badgers are capable of Superfetation (conception during pregnancy). This may increase female fitness by facilitating polyandry, and reduce the risk of infanticide by resident males through paternity confusion. Detailed understanding of female receptivity, specifically the association of super-fetation with embryonic diapause, may explain field observations of seemingly inconsistent reproductive 34 Volume 81THE QUARTERLY REVIEW OF BIOLOGY tactics of male badgers with regard to, for instance, whether or not they guard mates or defend territories. The combination of embryonic diapause and Superfetation may occur in other mustelids; if so, the sociobiology of mustelids will need re-evaluating, and the Mustelidae may prove to be a good model taxon for studies of sexual conflict in the reproduction of eutherian mammals. NATURAL SELECTION and sexual se-lection act on both sexes. However, em
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neighbouring group composition and within group relatedness drive extra group paternity rate in the european badger meles meles
Journal of Evolutionary Biology, 2014Co-Authors: Christina D Buesching, Chris Newman, Hannah L Dugdale, Geetha Annavi, Terry Burke, David W MacdonaldAbstract:Extra-group paternity (EGP) occurs commonly among group-living mammals and plays an important role in mating systems and the dynamics of sexual selection; however, socio-ecological and genetic correlates of EGP have been underexplored. We use 23 years of demographic and genetic data from a high-density European badger (Meles meles) population, to investigate the relationship between the rate of EGP in litters and mate availability, mate incompatibility and mate quality (heterozygosity). Relatedness between within-group assigned mothers and candidate fathers had a negative quadratic effect on EGP, whereas the number of neighbouring-group candidate fathers had a linear positive effect. We detected no effect of mean or maximum heterozygosity of within-group candidate fathers on EGP. Consequently, EGP was associated primarily with mate availability, subject to within-group genetic effects, potentially to mitigate mate incompatibility and inbreeding. In badgers, cryptic female choice, facilitated by superfecundation, superfoetation and delayed implantation, prevents males from monopolizing within-group females. This resonates with a meta-analysis in group-living mammals, which proposed that higher rates of EGP occur when within-group males cannot monopolize within-group females. In contrast to the positive meta-analytic association, however, we found that EGP associated negatively with the number of within-group assigned mothers and the number of within-group candidate fathers; potentially a strategy to counter within-group males committing infanticide. The relationship between the rate of EGP and socio-ecological or genetic factors can therefore be intricate, and the potential for cryptic female choice must be accounted for in comparative studies.
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Female receptivity, embryonic diapause, and Superfetation in the European badger (Meles meles): implications for the reproductive tactics of males and females.
The Quarterly review of biology, 2006Co-Authors: Nobuyuki Yamaguchi, Hannah L Dugdale, David W MacdonaldAbstract:ABSTRACT The European badger Meles meles is thought to mate throughout the year, with two mating peaks occurring in late winter/spring and summer/autumn. After mating, fertilized ova enter embryonic diapause (delayed implantation) at the blastocyst stage, which lasts up to eleven months. Even if mating is successful, however, the estrous cycle may continue during embryonic diapause, which suggests that female badgers are capable of Superfetation (conception during pregnancy). This may increase female fitness by facilitating polyandry, and reduce the risk of infanticide by resident males through paternity confusion. Detailed understanding of female receptivity, specifically the association of Superfetation with embryonic diapause, may explain field observations of seemingly inconsistent reproductive tactics of male badgers with regard to, for instance, whether or not they guard mates or defend territories. The combination of embryonic diapause and Superfetation may occur in other mustelids; if so, the soci...