共查询到20条相似文献，搜索用时 0 毫秒
1.
The mating system is expected to have an important influence on the evolution of mating and parenting behaviors. Although many studies have used experimental evolution to examine how mating behaviors evolve under different mating systems, this approach has seldom been used to study the evolution of parental care. We used experimental evolution to test whether adaptation to different mating systems involves changes in mating and parenting behaviors in populations of the burying beetle, Nicrophorus vespilloides. We maintained populations under monogamy or promiscuity for six generations. This manipulation had an immediate impact on reproductive performance and adult survival. Compared to monogamy, promiscuity reduced brood size and adult (particularly male) survival during breeding. After six generations of experimental evolution, there was no divergence between monogamous and promiscuous populations in mating behaviors. Parents from the promiscuous populations (especially males) displayed less care than parents from the monogamous populations. Our results are consistent with the hypothesis that male care will increase with the certainty of paternity. However, it appears that this change is not associated with a concurrent change in mating behaviors. 相似文献
2.
In species with biparental care, sexual conflict occurs because the benefit of care depends on the total amount of care provided by the two parents while the cost of care depends on each parent's own contribution. Asynchronous hatching may play a role in mediating the resolution of this conflict over parental care. The sexual conflict hypothesis for the evolution of asynchronous hatching suggests that females adjust hatching patterns in order to increase male parental effort relative to female effort. We tested this hypothesis in the burying beetle Nicrophorus vespilloides by setting up experimental broods with three different hatching patterns: synchronous, asynchronous and highly asynchronous broods. As predicted, we found that males provided care for longer in asynchronous broods whereas the opposite was true of females. However, we did not find any benefit to females of reducing their duration of care in terms of increased lifespan or reduced mass loss during breeding. We found substantial negative effects of hatching asynchrony on offspring fitness as larval mass was lower and fewer larvae survived to dispersal in highly asynchronous broods compared to synchronous or asynchronous broods. Our results suggest that, even though females can increase male parental effort by hatching their broods more asynchronously, females pay a substantial cost from doing so in terms of reducing offspring growth and survival. Thus, females should be under selection to produce a hatching pattern that provides the best possible trade‐off between the benefits of increased male parental effort and the costs due to reduced offspring fitness. 相似文献
3.
A. H. C. McLean A. N. Arce P. T. Smiseth D. E. Rozen 《Journal of evolutionary biology》2014,27(6):1205-1216
Intergenerational effects can have either adaptive or nonadaptive impacts on offspring performance. Such effects are likely to be of ecological and evolutionary importance in animals with extended parental care, such as birds, mammals and some insects. Here, we studied the effects of exposure to microbial competition during early development on subsequent reproductive success in the burying beetle Nicrophorus vespilloides, an insect with elaborate parental care. We found that exposure to high levels of microbial competition both during a female's larval development and during her subsequent reproduction resulted in females rearing smaller broods than those exposed to lower levels of microbial competition. To determine whether these differences arose before or after offspring hatching, a cross‐fostering experiment was conducted. Our results demonstrate that the impact of larval competition with microbes for resources extends into adult life and can negatively affect subsequent generations via impacts on the quality of parental care provided after hatching. However, we also find evidence for some positive effects of previous microbial exposure on prehatch investment, suggesting that the long‐term results of competition with microbes may include altering the balance of parental investment between prehatch and post‐hatch care. 相似文献
4.
Parental care is highly variable, reflecting that parents make flexible decisions in response to variation in the cost of care to themselves and the benefit to their offspring. Much of the evidence that parents respond to such variation derives from handicapping and brood size manipulations, the separate effects of which are well understood. However, little is known about their joint effects. Here, we fill this gap by conducting a joint handicapping and brood size manipulation in the burying beetle Nicrophorus vespilloides. We handicapped half of the females by attaching a lead weight to their pronotum, leaving the remaining females as controls. We also manipulated brood size by providing each female with 5, 20 or 40 larvae. In contrast to what we predicted, handicapped females spent more time provisioning food than controls. We also found that handicapped females spent more time consuming carrion. Furthermore, handicapped females spent a similar amount of time consuming carrion regardless of brood size, whereas controls spent more time consuming carrion as brood increased. Females spent more time provisioning food towards larger broods, and females were more likely to engage in carrion consumption when caring for larger broods. We conclude that females respond to both handicapping and brood size manipulations, but these responses are largely independent of each other. Overall, our results suggest that handicapping might lead to a higher investment into current reproduction and that it might be associated with compensatory responses that negate the detrimental impact of higher cost of care in handicapped parents. 相似文献
5.
Lucy E. Ford Kirsten J. Henderson Per T. Smiseth 《Journal of evolutionary biology》2018,31(7):1047-1057
We investigate the effect of offspring and maternal inbreeding on maternal and offspring traits associated with early offspring fitness in the burying beetle Nicrophorus vespilloides. We conducted two experiments. In the first experiment, we manipulated maternal inbreeding only (keeping offspring outbred) by generating mothers that were outbred, moderately inbred or highly inbred. Meanwhile, in the second experiment, we manipulated offspring inbreeding only (keeping females outbred) by generating offspring that were outbred, moderately inbred or highly inbred. In both experiments, we monitored subsequent effects on breeding success (number of larvae), maternal traits (clutch size, delay until laying, laying skew, laying spread and egg size) and offspring traits (hatching success, larval survival, duration of larval development and average larval mass). Maternal inbreeding reduced breeding success, and this effect was mediated through lower hatching success and greater larval mortality. Furthermore, inbred mothers produced clutches where egg laying was less skewed towards the early part of laying than outbred females. This reduction in the skew in egg laying is beneficial for larval survival, suggesting that inbred females adjusted their laying patterns facultatively, thereby partially compensating for the detrimental effects of maternal inbreeding on offspring. Finally, we found evidence of a nonlinear effect of offspring inbreeding coefficient on number of larvae dispersing. Offspring inbreeding affected larval survival and larval development time but also unexpectedly affected maternal traits (clutch size and delay until laying), suggesting that females adjust clutch size and the delay until laying in response to being related to their mate. 相似文献
6.
Tom Ratz Anastasia Perodaskalaki Jacob Moorad Per T. Smiseth 《Journal of evolutionary biology》2020,33(7):1006-1016
Inbreeding depression is defined as a fitness decline in progeny resulting from mating between related individuals, the severity of which may vary across environmental conditions. Such inbreeding‐by‐environment interactions might reflect that inbred individuals have a lower capacity for adjusting their phenotype to match different environmental conditions better, as shown in prior studies on developmental plasticity. Behavioural plasticity is more flexible than developmental plasticity because it is reversible and relatively quick, but little is known about its sensitivity to inbreeding. Here, we investigate effects of inbreeding on behavioural plasticity in the context of parent–offspring interactions in the burying beetle Nicrophorus vespilloides. Larvae increase begging with the level of hunger, and parents increase their level of care when brood sizes increase. Here, we find that inbreeding increased behavioural plasticity in larvae: inbred larvae reduced their time spent associating with a parent in response to the length of food deprivation more than outbred larvae. However, inbreeding had no effect on the behavioural plasticity of offspring begging or any parental behaviour. Overall, our results show that inbreeding can increase behavioural plasticity. We suggest that inbreeding‐by‐environment interactions might arise when inbreeding is associated with too little or too much plasticity in response to changing environmental conditions. 相似文献
7.
Matthew Schrader Benjamin J. M. Jarrett Rebecca M. Kilner 《Evolution; international journal of organic evolution》2015,69(4):1077-1084
Studies of siblings have focused mainly on their competitive interactions and to a lesser extent on their cooperation. However, competition and cooperation are at opposite ends on a continuum of possible interactions and the nature of these interactions may be flexible with ecological factors tipping the balance toward competition in some environments and cooperation in others. Here we show that the presence of parental care and the density of larvae on the breeding carcass change the outcome of sibling interactions in burying beetle broods. With full parental care there was a strong negative relationship between larval density and larval mass, consistent with sibling competition for resources. In the absence of care, initial increases in larval density had beneficial effects on larval mass but further increases in larval density reduced larval mass. This likely reflects a density‐dependent shift between cooperation and competition. In a second experiment, we manipulated larval density and removed parental care. We found that the ability of larvae to penetrate the breeding carcass increased with larval density and that feeding within the carcass resulted in heavier larvae than feeding outside the carcass. However, larval density did not influence carcass decay. 相似文献
8.
Nicrophorusvespilloides is a social beetle that rears its offspring on decomposing carrion. Wild beetles are frequently associated with two types of macrobial symbionts, mites, and nematodes. Although these organisms are believed to be phoretic commensals that harmlessly use beetles as a means of transfer between carcasses, the role of these symbionts on N. vespilloides fitness is poorly understood. Here, we show that nematodes have significant negative effects on beetle fitness across a range of worm densities and also quantify the density‐dependent transmission of worms between mating individuals and from parents to offspring. Using field‐caught beetles, we provide the first report of a new nematode symbiont in N. vespilloides, most closely related to Rhabditoides regina, and show that worm densities are highly variable across individuals isolated from nature but do not differ between males and females. Next, by inoculating mating females with increasing densities of nematodes, we show that worm infections significantly reduce brood size, larval survival, and larval mass, and also eliminate the trade‐off between brood size and larval mass. Finally, we show that nematodes are efficiently transmitted between mating individuals and from mothers to larvae, directly and indirectly via the carcass, and that worms persist through pupation. These results show that the phoretic nematode R. regina can be highly parasitic to burying beetles but can nevertheless persist because of efficient mechanisms of intersexual and intergenerational transmission. Phoretic species are exceptionally common and may cause significant harm to their hosts, even though they rely on these larger species for transmission to new resources. However, this harm may be inevitable and unavoidable if transmission of phoretic symbionts requires nematode proliferation. It will be important to determine the generality of our results for other phoretic associates of animals. It will equally be important to assess the fitness effects of phoretic species under changing resource conditions and in the field where diverse interspecific interactions may exacerbate or reduce the negative effects of phoresy. 相似文献
9.
Parents can increase the fitness of their offspring by allocating nutrients to eggs and/or providing care for eggs and offspring. Although we have a good understanding of the adaptive significance of both egg size and parental care, remarkably little is known about the co-evolution of these two mechanisms for increasing offspring fitness. Here, we report a parental removal experiment on the burying beetle Nicrophorus vespilloides in which we test whether post-hatching parental care masks the effect of egg size on offspring fitness. As predicted, we found that the parent's presence or absence had a strong main effect on larval body mass, whereas there was no detectable effect of egg size. Furthermore, egg size had a strong and positive effect on offspring body mass in the parent's absence, whereas it had no effect on offspring body mass in the parent's presence. These results support the suggestion that the stronger effect of post-hatching parental care on offspring growth masks the weaker effect of egg size. We found no correlation between the number and size of eggs. However, there was a negative correlation between larval body mass and brood size in the parent's presence, but not in its absence. These findings suggest that the trade-off between number and size of offspring is shifted from the egg stage towards the end of the parental care period and that post-hatching parental care somehow moderates this trade-off. 相似文献
10.
Inbreeding results from matings between relatives and can cause a reduction in offspring fitness, known as inbreeding depression. Previous work has shown that a wide range of environmental stresses, such as extreme temperatures, starvation and parasitism, can exacerbate inbreeding depression. It has recently been argued that stresses due to intraspecific competition should have a stronger effect on the severity of inbreeding depression than stresses due to harsh physical conditions. Here, we tested whether an increase in the intensity of sibling competition can exacerbate inbreeding depression in the burying beetle Nicrophorus vespilloides. We used a 2 × 3 factorial design with offspring inbreeding status (outbred or inbred) and brood size (5, 20, or 40 larvae) as the two factors. We found a main effect of inbreeding status, as inbred larvae had lower survival than outbred larvae, and a main effect of brood size, as larvae in large broods had lower survival and mass than larvae in medium‐sized broods. However, there was no effect of the interaction between inbreeding status and brood size, suggesting that sibling competition did not influence the severity of inbreeding depression. Since we focused on sibling competition within homogeneous broods of either inbred or outbred larvae, we cannot rule out possible effects of sibling competition on inbreeding depression in mixed paternity broods comprising of both inbred and outbred offspring. More information on whether and when sibling competition might influence inbreeding depression can help advance our understanding of the causes underlying variation in the severity of inbreeding depression. 相似文献
11.
Handicapping experiments on species with biparental care show that a focal parent increases its contribution when its partner is handicapped. Such results are interpreted as evidence for negotiation, whereby each parent adjusts its amount of care to that of its partner. However, it is currently unclear whether the focal parent responds to a change in its handicapped partner's behaviour or state. To address this gap, we conducted an experiment on the burying beetle Nicrophorus vespilloides where we first generated different‐sized males and females by varying the duration of larval development. We then used a 2 × 2 factorial design in which a small or large male was paired with a small or large female. Small females provided less direct care (food provisioning and interactions with larvae) than large females, and both males and females provided less direct care when paired with a small partner. Thus, the focal parent adjusted its contribution towards care based on both its own state and that of its partner. There was also evidence for negotiation between the two parents as the focal parent adjusted its contribution based on the amount of care by its partner. However, there was no evidence that negotiation accounted for how the focal parent responded to its partner's size. Our results have important implications for our understanding of biparental cooperation as they show that each parent adjusts its contribution not only based on the amount of care provided by its partner but also based on its own state and its partner's state. 相似文献
12.
The sharing of the same food source among parents and offspring can be a driver of the evolution of family life and parental care. However, if all family members desire the same meal, competitive situations can arise, especially if resource depletion is likely. When food is shared for reproduction and the raising of offspring, parents have to decide whether they should invest in self‐maintenance or in their offspring and it is not entirely clear how these two strategies are balanced. In the burying beetle Nicrophorus vespilloides, parents care for their offspring either bi‐ or uniparentally at a vertebrate carcass as the sole food source. The question of whether biparental care in this species offers the offspring a better environment for development compared with uniparental care has been the subject of some debate. We tested the hypothesis that male contribution to biparental brood care has a beneficial effect on offspring fitness but that this effect can be masked because the male also feeds from the shared resource. We show that a mouse carcass prepared by two Nicrophorus beetles is lighter compared with a carcass prepared by a single female beetle at the start of larval hatching and provisioning. This difference in carcass mass can influence offspring fitness when food availability is limited, supporting our hypothesis. Our results provide new insights into the possible evolutionary pathway of biparental care in this species of burying beetles. 相似文献
13.
Sarah N. Mattey Per T. Smiseth 《Ethology : formerly Zeitschrift fur Tierpsychologie》2015,121(11):1031-1038
Inbreeding avoidance reduces the probability that an individual will mate with a related partner, thereby lowering the risk that it produces inbred offspring suffering from inbreeding depression. Inbreeding avoidance can occur through several mechanisms, including active mate choice, polyandry and sex‐biased dispersal. Here, we focus on the role of active mate choice as a mechanism for inbreeding avoidance. Recent evidence suggests that the experimental design used in mate choice experiments (i.e. simultaneous versus sequential choice) can have a strong impact on the strength of the reported mating preferences. In this study, we examine whether similar effects of experimental design also apply in the context of inbreeding avoidance. To this end, we designed two experiments on the burying beetle Nicrophorus vespilloides that matched two different contexts under which females encounter potential mates in the wild; that is, when females encounter males simultaneously and sequentially. We found that females were as likely to mate with related and unrelated males regardless of whether they encountered male partners simultaneously or sequentially. Thus, our study provides no evidence for inbreeding avoidance in this species, and suggests that the number of mates present did not influence the degree of inbreeding avoidance. We discuss potential explanations for the lack of inbreeding avoidance through mate choice, including lack of mechanisms for recognizing close relatives, low costs and/or low risks of inbreeding and the presence of other inbreeding avoidance mechanisms, such as sex‐biased dispersal and polyandry coupled with post‐copulatory mate choice. 相似文献
14.
Individual variation in resource acquisition should have consequences for life‐history traits and trade‐offs between them because such variation determines how many resources can be allocated to different life‐history functions, such as growth, survival and reproduction. Since resource acquisition can vary across an individual's life cycle, the consequences for life‐history traits and trade‐offs may depend on when during the life cycle resources are limited. We tested for differential and/or interactive effects of variation in resource acquisition in the burying beetle Nicrophorus vespilloides. We designed an experiment in which individuals acquired high or low amounts of resources across three stages of the life cycle: larval development, prior to breeding and the onset of breeding in a fully crossed design. Resource acquisition during larval development and prior to breeding affected egg size and offspring survival, respectively. Meanwhile, resource acquisition at the onset of breeding affected size and number of both eggs and offspring. In addition, there were interactive effects between resource acquisition at different stages on egg size and offspring survival. However, only when females acquired few resources at the onset of breeding was there evidence for a trade‐off between offspring size and number. Our results demonstrate that individual variation in resource acquisition during different stages of the life cycle has important consequences for life‐history traits but limited effects on trade‐offs. This suggests that in species that acquire a fixed‐sized resource at the onset of breeding, the size of this resource has larger effects on life‐history trade‐offs than resources acquired at earlier stages. 相似文献
15.
Carrion beetles, Nicrophorus vespilloides, are reared on decomposing carrion where larvae are exposed to high populations of carcass‐derived bacteria. Larvae do not become colonized with these bacteria but instead are colonized with the gut microbiome of their parents, suggesting that bacteria in the beetle microbiome outcompete the carcass‐derived species for larval colonization. Here, we test this hypothesis and quantify the fitness consequences of colonization with different bacterial symbionts. First, we show that beetles colonized by their endogenous microbiome produce heavier broods than those colonized with carcass‐bacteria. Next, we show that bacteria from the endogenous microbiome, including Providencia rettgeri and Morganella morganii, are better colonizers of the beetle gut and can outcompete nonendogenous species, including Serratia marcescens and Escherichia coli, during in vivo competition. Finally, we find that Providencia and Morganella provide beetles with colonization resistance against Serratia and thereby reduce Serratia‐induced larval mortality. This effect is eliminated in larvae first colonized by Serratia, suggesting that while competition within the larval gut is determined by priority effects, these effects are less important for Serratia‐induced mortality. Our work suggests that an unappreciated benefit of parental care in N. vespilloides is the social transmission of the microbiome from parents to offspring. 相似文献
16.
According to classical parental care theory males are expected to provide less parental care when offspring in a brood are less likely to be their own, but empirical evidence in support of this relationship is equivocal. Recent work predicts that social interactions between the sexes can modify co‐evolution between traits involved in mating and parental care as a result of costs associated with these social interactions (i.e. sexual conflict). In burying beetles (Nicrophorus vespilloides), we use artificial selection on a paternity assurance trait, and crosses within and between selection lines, to show that selection acting on females, not males, can drive the co‐evolution of paternity assurance traits and parental care. Males do not care more in response to selection on mating rate. Instead, patterns of parental care change as an indirect response to costs of mating for females. 相似文献
17.
S. Suzuki 《Journal of Ethology》2000,18(1):25-28
I studied the influence of carrion burial on the interaction between Nicrophorus quadripunctatus and Nicrophorus vespilloides. In the preburial phase, N. quadripunctatus, the smaller species, occupied more carcasses than N. vespilloides, the larger species, when both species were allowed to compete for mouse carcasses. However, after carcasses were buried, N. vespilloides was more successful in protecting those it had buried, and more successful in intruding on carcasses buried by N. quadripunctatus. Direct observation supported these findings. These results may suggest that N. vespilloides is cleptoparasitic on N. quadripunctatus for carrion burial. Received: March 25, 1999 / Accepted: August 31, 1999 相似文献
18.
Mhairi Miller Tom Ratz Jon Richardson Per T. Smiseth 《Journal of evolutionary biology》2019,32(1):89-99
Theory suggests that intraspecific competition associated with direct competition between inbred and outbred individuals should be an important determinant of the severity of inbreeding depression. The reason is that, if outbred individuals are stronger competitors than inbred ones, direct competition should have a disproportionate effect on the fitness of inbred individuals. However, an individual's competitive ability is not only determined by its inbreeding status but also by competitive asymmetries that are independent of an individual's inbreeding status. When this is the case, such competitive asymmetries may shape the outcome of direct competition between inbred and outbred individuals. Here, we investigate the interface between age‐based competitive asymmetries within broods and direct competition between inbred and outbred offspring in the burying beetle Nicrophorus vespilloides. We found that inbred offspring had lower survival than outbred ones confirming that there was inbreeding depression. Furthermore, seniors (older larvae) grew to a larger size and had higher survival than juniors (younger larvae), confirming that there were age‐based competitive asymmetries. Nevertheless, there was no evidence that direct competition between inbred and outbred larvae exacerbated inbreeding depression, no evidence that inbreeding depression was more severe in juniors and no evidence that inbred juniors suffered disproportionately due to competition from outbred seniors. Our results suggest that direct competition between inbred and outbred individuals does not necessarily exacerbate inbreeding depression and that inbred individuals are not always more sensitive to poor and stressful conditions than outbred ones. 相似文献
19.
Parental care benefits offspring through maternal effects influencing their development, growth and survival. However, although parental care in general is likely the result of adaptive evolution, it does not follow that specific differences in the maternal effects that arise from care are also adaptive. Here, we used an interspecific cross‐fostering design in the burying beetle species Nicrophorus orbicollis and N. vespilloides, both of which have elaborate parental care involving direct feeding of regurgitated food to offspring, to test whether maternal effects are optimized within a species and therefore adaptive. Using a full‐factorial design, we first demonstrated that N. orbicollis care for offspring longer regardless of recipient species. We then examined offspring development and mass in offspring reared by hetero‐ or conspecific parents. As expected, there were species‐specific direct effects independent of the maternal effects, as N. orbicollis larvae were larger and took longer to develop than N. vespilloides regardless of caregiver. We also found significant differences in maternal effects: N. vespilloides maternal care caused more rapid development of offspring of either species. Contrary to expectations if maternal effects were species‐specific, there were no significant interactions between caretaker and recipient species for either development time or mass, suggesting that these maternal effects are general rather than optimized within species. We suggest that rather than coadaptation between parents and offspring performance, the species differences in maternal effects may be correlated with direct effects, and that their evolution is driven by selection on those direct effects. 相似文献
20.
Burying beetles (Nicrophorus orbicollis) are unusual in that to breed they require an unpredictable and valuable resource, a small carcass. Thus the timing of reproduction is unpredictable and beetles' physiological response must be fast. We hypothesized that their pattern of vitellogenin (Vg) synthesis might reflect these requirements. We examined the expression of two Vg genes (sequenced for this study) during sexual maturation and through a reproductive bout. Vg-mRNA, juvenile hormone (JH) titers, ovarian development, and hemolymph concentrations of Vg were quantified in the same individuals. All four variables gradually increased during maturation to peak 15-20 days after eclosion. Twelve hours after the discovery of a carcass, a few hours before oviposition, mRNA was high, hemolymph Vg had decreased, JH and ovarian weight had increased. After oviposition, mRNA was low, hemolymph Vg concentrations and JH were high. This is consistent with our hypothesis that beetles produce and store Vg in the hemolymph prior to the discovery of a breeding resource and replace it quickly. Partial regression of these variables (with the effect of time removed) indicated that JH was not correlated with mRNA, hemolymph Vg, or ovarian weight at any time. Thus the role of JH as a gonadotropin remains unclear. 相似文献