Studies of siblings have focused mainly on their competitive interactions and to a lesser extent cooperation. However, competition cooperation are at opposite ends continuum possible the nature these may be flexible with ecological factors tipping balance toward in some environments others. Here we show that presence parental care density larvae breeding carcass change outcome sibling burying beetle broods. With full there was strong negative relationship between larval mass, consistent for...

Species pairs whose distributions are tied to environmental conditions provide intriguing candidates for the study of ecological speciation. Here, we examine role that adaptation salinity has played in divergence between two closely related species, Lucania goodei and parva, reflect (L. goodei- fresh water, L. parva- euryhaline). We first tested whether these species display local and, subsequently, ecological, genic behavioural isolation by performing crosses within parva raising offspring...

Some group-living species exhibit social immunity, where the immune response of one individual can protect others in group from infection. In burying beetles, this is part parental care. Larvae feed on vertebrate carcasses which their parents smear with exudates that inhibit microbial growth. We have sequenced transcriptome beetle Nicrophorus vespilloides and identified six genes encode lysozymes—a type antimicrobial enzyme has previously been implicated immunity beetles. When females start...

Parents of many species provision their young, and the extent parental provisioning constitutes a major component offspring's social environment. Thus, change in can alter selection on offspring, resulting coevolution offspring traits. Although this reasoning is central to our evolutionary understanding family life, there little direct evidence that by parents causes offspring. Here we use experimental evolution examine how populations burying beetles adapt posthatching provisioning. We...

Abstract Although cooperative social interactions within species are considered an important driver of evolutionary change, few studies have experimentally demonstrated that they cause adaptive evolution. Here we address this problem by studying the burying beetle Nicrophorus vespilloides . In species, parents and larvae work together to obtain nourishment for from carrion breeding resource: feed also self-feed. We established evolving populations in which varied assistance provided their...

The joint actions of animals in partnerships or social groups evolve under both natural selection from the wider environment and imposed by other members pair group. We used experimental evolution to investigate how jointly expressed upon exposure a new environmental challenge. Our work focused on carrion nest preparation pairs burying beetles

Abstract We examined seasonal prevalence of a haematozoan parasite (Haemoproteus velans) the Red-bellied Woodpecker (Melanerpes carolinus) in Apalachicola National Forest, northern Florida. also investigated how infection with H. velans was associated host mass, body condition, and overwinter survival. Analysis blood smears taken from individual woodpeckers between May 2000 July 2001 indicated that peaked 2000, at ∼80% individuals sampled, decreased to 0% January February 2001, again ∼50%...

The evolution of viviparity increases the potential for genomic conflicts between mothers and offspring over level maternal investment. viviparity‐driven‐conflict hypothesis predicts that such will drive asymmetrical reproductive isolation populations with divergent mating systems. We tested this using crosses a poeciliid fish differ in their polyandry. Our results support prediction an asymmetry rate spontaneous abortion reciprocal crosses, highest occurring females from relatively...

The evolution of matrotrophy introduces the potential for genomic conflicts between mothers and embryos. These are hypothesized to accelerate reproductive isolation influence life‐history traits, structures, imprinting. hypotheses assume offspring can amount maternal investment they receive that there is a trade‐off into individual survival or fecundity. We used field data laboratory crosses test whether these assumptions met in matrotrophic poeciliid fish Heterandria formosa. Comparisons...

Population density is an ecological variable that hypothesized to be a major agent of selection on offspring size. In high-density populations, high levels intraspecific competition are expected favor the production larger offspring. contrast, lower and for large should weaker more easily overridden by direct increased fecundity in low-density populations. Some studies have found associations between population size consistent with this hypothesis. However, their interpretations often...

Cryptic evolution occurs when evolutionary change is masked by concurrent environmental change. In most cases, changes in the phenotype are changing abiotic factors. However, one trait might also be another trait, a phenomenon referred to as deterioration. Nevertheless, detecting this second type of cryptic challenging and there few compelling examples. Here, we describe likely case deterioration occurring experimental burying beetle (Nicrophorus vespilloides) populations that adapting novel...

Many inferences about contemporary rates of gene flow are based on the assumption that observed genetic structure among populations is stable. Recent studies have uncovered several cases in which this tenuous. Most those focused effects regular environmental fluctuations can and patterns. Occasional catastrophic disturbances could also alter either distribution habitat or spatial organisms a way affects population structure. However, evidence such sparse literature because it difficult to...

Asymmetric sibling competition arises when siblings with different competitive abilities share a limited resource. Such occurs in species postnatal parental care and may also occur mothers provision embryos between fertilization birth (matrotrophy). We hypothesized that the combination of matrotrophy simultaneous provisioning stages development (superfetation) leads to asymmetric embryos. Moreover, we expect intensity this increase level superfetation as high levels result greater temporal...

We used data from a long-term field study of two populations the Least Killifish, Heterandria formosa, to examine whether genetically based population differences in offspring size at birth are mainly due pre-fertilization provisioning (i.e., egg mass) or post-fertilization degree matrotrophy). found between and larger provisioning. These results establish variation H. formosa as potential model for studying costs benefits that could modulate evolution matrotrophy. In addition, our...

Abstract It is often assumed that there a positive relationship between egg size and offspring fitness. However, recent studies have suggested has greater effect on fitness in low‐quality environments than high‐quality environments. Such observations suggest mothers may compensate for poor posthatching by increasing size. In this paper we test whether limit the extent to which increased can removal of parental care burying beetle, Nicrophorus vespilloides . Previous experiments with N. an...

Several recent hypotheses suggest that parental care can influence the extent of phenotypic variation within populations; however, there have been few tests these ideas. We exploited facultative nature posthatching in burying beetle, Nicrophorus vespilloides, to test whether influences expression an important fitness trait (body size). found and brood size (which sibling competition) had positive independent effects on body size. First, mean coefficient (CV) was significantly greater broods...

Matrotrophy, the provisioning of embryos between fertilization and birth, creates potential for conflict mothers over level maternal investment. This is predicted to drive evolution reproductive isolation populations with different mating systems. In this study, we examine whether density-driven system differences explain patterns asymmetric observed in previous studies involving four matrotrophic least killifish, Heterandria formosa. Minimum sire number reconstructions suggested that two...

Crosses between populations or species often display an asymmetry in the fitness of reciprocal F1 hybrids. This pattern, referred to as isolation Darwin's Corollary Haldane's Rule, has been observed taxa from plants vertebrates, yet we still know little about which factors determine its magnitude and direction. Here, show that differences offspring size predict direction crosses a placental fish, Heterandria formosa. In with size, high rates hybrid inviability occur only when mother is...

The presence of stable color polymorphisms within populations begs the question how genetic variation is maintained. Consistent among in coloration, especially when correlated with environmental variation, raises questions about whether conditions affect either fulcrum those balanced polymorphisms, plastic expression or both. Color patterns male bluefin killifish provoke both types questions. Red and yellow morphs are common all populations. Blue males more tannin-stained swamps relative to...

We investigated patterns of seasonal variation in body weight six populations five resident species temperate-zone woodpeckers: Acorn Woodpecker (Melanerpes formicivorus), Red-bellied (M. carolinus), Red-cockaded (Picoides borealis), Downy (P. pubescens), and Great Spotted (Dendrocopos major). After controlling for time day overall size, annual was small generally not statistically significant. However, analysis revealed evidence significant "winter fattening," comparable magnitude to other...

Abstract Parental care has been shown to reduce the magnitude of inbreeding depression in some species with facultative care. However, parents often vary quality or amount they provide their offspring, and it is less clear whether this variation also impacts depression. Here, we tested age‐related changes parental modulate expression burying beetle, Nicrophorus orbicollis . Consistent previous studies, found that older produced larger broods offspring than younger without sacrificing mean...

Seventy-four red-bellied woodpeckers (Melanerpes carolinus) from the Apalachicola National Forest (30°10′N, 84°40′W) in northwest Florida were examined for helminths. The most prevalent parasites nematode Aproctella stoddardi (11%) and acanthocephalan Mediorhynchus centurorum (11%). New host records include Pseudaprocta samueli, A. stoddardi, Tridentocapillaria tridens, Diplotriaena americana, Dispharynx nasuta, Procyrnea pileata, Orthoskrjabinia rostellata, Brachylaima fuscatum. helminth...

In organisms that provision young between fertilization and birth, mothers their developing embryos are expected to be in conflict over embryonic growth. mammalian embryos, the expression of Insulin-like growth factor II (IGF2) plays a key role maternal-fetal interactions is thought focus conflict. Recent studies have suggested IGF2 also placental fish family Poeciliidae. However, whether influences offspring size, trait which likely conflict, has not been assessed poeciliid. We tested...