Coevolution of longevity and female germline maintenance.

An often-overlooked aspect of life-history optimization is the allocation of resources to protect the germline and secure safe transmission of genetic information. While failure to do so renders significant fitness consequences in future generations, germline maintenance comes with substantial costs. Thus, germline allocation should trade off with other life-history decisions and be optimized in accordance with an organism's reproductive schedule. Here, we tested this hypothesis by studying germline maintenance in lines of seed beetle, selected for early (E) or late (L) reproduction for 350 and 240 generations, respectively. Female animals provide maintenance and screening of male gametes in their reproductive tract and oocytes. Here, we reveal the ability of young and aged E- and L-females to provide this form of germline maintenance by mating them to males with ejaculates with artificially elevated levels of protein and DNA damage. We find that germline maintenance in E-females peaks at young age and then declines, while the opposite is true for L-females, in accordance with the age of reproduction in the respective regime. These findings identify the central role of allocation to secure germline integrity in life-history evolution and highlight how females can play a crucial role in mitigating the effects of male germline decisions on mutation rate and offspring quality.

Maternal Care under Large Clutches with Small Eggs: The Evolution of Life History Traits in Shield Bugs.

AbstractPatterns in the correlated evolution of parental care and life history traits are long established but controversial. Although parental care is related to large egg size in many taxa, conflicting results have also been reported. To test the evolutionary relationships between parental care and life history traits, we performed phylogenetic comparative analyses using shield bugs (Heteroptera: Acanthosomatidae), in which maternal guarding of eggs and young has repeatedly evolved. Our analyses revealed that female body size affected reproductive resource allocation. Contrary to the expectations of current theories, the acquisition of maternal care was associated with small eggs, large clutches, and large egg resource allocation. There was a greater trade-off between egg size and clutch size in caring species than in noncaring species. Egg and hatchling developmental rates were not correlated with egg size but were slower in caring species than in noncaring species. Analyses of evolutionary transitions suggest that the establishment of large clutches, small eggs, and large egg resource allocation preceded the evolution of maternal care. To our knowledge, this is the first study clarifying the evolution of parental care linked with small eggs in invertebrates.

Exploring the Unique and Interactive Effects Between Callous-Unemotional and Autistic Traits with Parental Practices, Care, and Distress in a Community Sample.

Parental practices and stress are associated with both CU and autistic traits, with parents of children with these traits facing challenges that other parents do not encounter. However, the majority of available studies focused mainly on the unique effects of CU and autistic traits with parental stress and practices without exploring their interaction. The current study examines the distinct associations and interactions between CU and autistic traits with parental practices (parental involvement, poor monitoring, inconsistent discipline, and corporal punishment), care, and distress after considering the effect of conduct problems (CPs), age and sex in a Greek-Cypriot sample (N = 146, Mage = 7.30, SD = 1.43). Hierarchical multiple regression analysis revealed that children with CU traits were more likely to experience negative parenting, while parents showed heightened levels of distress. Notably, the study found no association between CU traits and positive parental practices. Further analysis indicated no significant relation between autistic traits and interactions with the target variables, signifying that these traits are not associated with difficulties in parenting and distress. No sex differences were found in all analyses. Age was negatively significant only in relation to parental distress These findings provide valuable insights into the impact of CU traits and underscore the need for additional studies investigating the impact of autistic traits, possibly within clinical samples.

Understanding forms of childhood adversities and associations with adult health outcomes: A regression tree analysis.

BACKGROUND: Empirical studies have demonstrated associations between ten original adverse childhood experiences (ACEs) and multiple health outcomes. Identifying expanded ACEs can capture the burden of other childhood adversities that may have important health implications. OBJECTIVE: We sought to identify childhood adversities that warrant consideration as expanded ACEs. We hypothesized that experiencing expanded and original ACEs would be associated with poorer adult health outcomes compared to experiencing original ACEs alone. PARTICIPANTS: The 11,545 respondents of the National Longitudinal Surveys (NLS) and Child and Young Adult Survey were 48.9 % female, 22.7 % Black, 15.8 % Hispanic, 36.1 % White, 1.7 % Asian/Native Hawaiian/Pacific Islander/Native American/Native Alaskan, and 7.5 % Other. METHODS: This study used regression trees and generalized linear models to identify if/which expanded ACEs interacted with original ACEs in association with six health outcomes. RESULTS: Four expanded ACEs-basic needs instability, lack of parental love and affection, community stressors, and mother's experience with physical abuse during childhood -significantly interacted with general health, depressive symptom severity, anxiety symptom severity, and violent crime victimization in adulthood (all p-values <0.005). Basic needs instability and/or lack of parental love and affection emerged as correlates across multiple outcomes. Experiencing lack of parental love and affection and original ACEs was associated with greater anxiety symptoms (p = 0.022). CONCLUSIONS: This is the first study to use supervised machine learning to investigate interaction effects among original ACEs and expanded ACEs. Two expanded ACEs emerged as predictors for three adult health outcomes and warrant further consideration in ACEs assessments.

Puppy whines mediate maternal behavior in domestic dogs.

In mammals, offspring vocalizations typically encode information about identity and body condition, allowing parents to limit alloparenting and adjust care. But how do these vocalizations mediate parental behavior in species faced with the problem of rearing not one, but multiple offspring, such as domestic dogs? Comprehensive acoustic analyses of 4,400 whines recorded from 220 Beagle puppies in 40 litters revealed litter and individual (within litter) differences in call acoustic structure. By then playing resynthesized whines to mothers, we showed that they provided more care to their litters, and were more likely to carry the emitting loudspeaker to the nest, in response to whine variants derived from their own puppies than from strangers. Importantly, care provisioning was attenuated by experimentally moving the fundamental frequency (fo, perceived as pitch) of their own puppies' whines outside their litter-specific range. Within most litters, we found a negative relationship between puppies' whine fo and body weight. Consistent with this, playbacks showed that maternal care was stronger in response to high-pitched whine variants simulating relatively small offspring within their own litter's range compared to lower-pitched variants simulating larger offspring. We thus show that maternal care in a litter-rearing species relies on a dual assessment of offspring identity and condition, largely based on level-specific inter- and intra-litter variation in offspring call fo. This dual encoding system highlights how, even in a long-domesticated species, vocalizations reflect selective pressures to meet species-specific needs. Comparative work should now investigate whether similar communication systems have convergently evolved in other litter-rearing species.

The evolution of sex roles: The importance of ecology and social environment.

Males and females often have different roles in reproduction, although the origin of these differences has remained controversial. Explaining the enigmatic reversed sex roles where males sacrifice their mating potential and provide full parental care is a particularly long-standing challenge in evolutionary biology. While most studies focused on ecological factors as the drivers of sex roles, recent research highlights the significance of social factors such as the adult sex ratio. To disentangle these propositions, here, we investigate the additive and interactive effects of several ecological and social factors on sex role variation using shorebirds (sandpipers, plovers, and allies) as model organisms that provide the full spectrum of sex role variation including some of the best-known examples of sex-role reversal. Our results consistently show that social factors play a prominent role in driving sex roles. Importantly, we show that reversed sex roles are associated with both male-skewed adult sex ratios and high breeding densities. Furthermore, phylogenetic path analyses provide general support for sex ratios driving sex role variations rather than being a consequence of sex roles. Together, these important results open future research directions by showing that different mating opportunities of males and females play a major role in generating the evolutionary diversity of sex roles, mating system, and parental care.

Androgen and glucocorticoid profiles throughout extended uniparental paternal care in the eastern hellbender salamander (Cryptobranchus a. alleganiensis).

The behavioral endocrinology associated with reproduction and uniparental male care has been studied in teleosts, but little is known about hormonal correlates of uniparental male care in other ectotherms. To address this gap, we are the first to document the seasonal steroid endocrinology of uniparental male hellbender salamanders during the transition from pre-breeding to nest initiation, and through the subsequent eight months of paternal care. In doing so, we investigated the correlates of nest fate and clutch size, exploring hellbenders' alignment with several endocrinological patterns observed in uniparental male fish. Understanding the endocrinology of hellbender paternal care is also vital from a conservation perspective because high rates of nest failure were recently identified as a factor causing population declines in this imperiled species. We corroborated previous findings demonstrating testosterone and dihydrotestosterone (DHT) to be the primary androgens in hellbender reproduction, and that cortisol circulates as the most abundant glucocorticoid. However, we were unable to identify a prolactin or a "prolactin-like" peptide in circulation prior to or during parental care. We observed âˆ¼ 80 % declines in both primary androgens during the transition from pre-breeding to nest initiation, and again as paternal care progressed past its first month. In the days immediately following nest initiation, testosterone and DHT trended higher in successful individuals, but did not differ with males' clutch size. We did not observe meaningful seasonality in baseline glucocorticoids associated with breeding or nesting. In contrast, stress-induced glucocorticoids were highest at pre-breeding and through the first two months of care, before declining during the latter-most periods of care as larvae approach emergence from the nest. Neither baseline nor stress-induced glucocorticoids varied significantly with either nest fate or clutch size. Both stress-induced cortisol and corticosterone were positively correlated with total length, a proxy for age in adult hellbenders. This is consistent with age-related patterns in some vertebrates, but the first such pattern observed in a wild amphibian population. Generally, we found that nesting hellbenders adhere to some but not all of the endocrinological patterns observed in uniparental male teleosts prior to and during parental care.

Short-term heat waves have long-term consequences for parents and offspring in stickleback.

Extreme temperature events, such as heat waves, can have lasting effects on the behavior, physiology, and reproductive success of organisms. Here, we examine the impact of short-term exposure to a simulated heat wave on condition, parental care, and reproductive success in a population of threespine stickleback (Gasterosteus aculeatus), a small fish with exclusive paternal care, currently experiencing regular heat waves. Males were either exposed to a simulated heat wave (23 °C) for 5 d or held at an ideal temperature (18 °C). Following this 5-d treatment, all males were transferred to 18 °C, where they completed a full parenting cycle. Offspring were raised at 18 °C. We found that while mass and body condition were unaffected in males exposed to a heat wave, cortisol responses were dampened across the nesting cycle compared to control males. In addition, heat wave males had longer latency for eggs to hatch, lower hatching success, and showed lower levels of parental care behavior compared to control males. Offspring of heat wave males had lower body condition, affecting swimming performance. Altogether, our results highlight the long-term impact that even short-term events can have on reproductive success, parental behavior, and subsequent generations, providing insight into population responses to rapid environmental change.

Exploring the role of OXTR gene methylation in attachment development: A longitudinal study.

The current study explored longitudinally whether oxytocin receptor gene methylation (OXTRm) changes moderated the association between parental sensitivity changes and children's attachment changes over three waves. Six hundred six Flemish children (10-12 years, 42.8%-44.8% boys) completed attachment measures and provided salivary OXTRm data on seven CpG sites. Their parents reported their sensitive parenting. Results suggest that OXTRm changes hardly link to attachment (in)security changes after the age of 10. Some support was found for interaction effects between parental sensitivity changes and OXTRm changes on attachment changes over time. Effects suggest that for children with increased OXTRm in the promotor region and decreased methylation in the inhibitor region over time, increased parental sensitivity was associated with increased secure attachment and decreased insecure attachment over time.

Prolactin is associated with proximity to incubating partner rather than parental care in black-headed gulls.

The peptide hormone prolactin plays an important role in the expression of parental care behaviours across bird and mammal taxa. While a great deal is known about how plasma prolactin concentrations vary across the reproductive cycle, the few studies that investigate how prolactin relates to individual-level variation in parental care have reported mixed results. We argue that, since parental care is also affected by social interactions and environmental constraints, prolactin may better reflect behaviours that are indirectly related to parenting than the absolute level of care that is eventually expressed. In this study, we tested for associations between plasma prolactin and the expression of both parental care and proximity to the partner in incubating black-headed gulls, Chroicocephalus ridibundus. Baseline prolactin levels increased with calendar date but were unrelated to incubation behaviours. However, parents who showed a weaker decrease in prolactin to an acute stressor spent more time in close proximity to their incubating partner while not on the nest themselves, suggesting that individual variation in stress-induced prolactin changes reflect differences in parents' tendency to be closely associated with their partner and the joint nesting attempt. Baseline and stress-induced levels of the stress hormone corticosterone were unrelated to both prolactin levels and parental behaviours, suggesting that this hormone is not a strong moderator of parental care in black-headed gulls. One potential explanation for the link between prolactin dynamics and partner proximity is that prolactin reflects parental motivation to provide parental care or retain contact with the breeding partner, but further work is needed to directly test this hypothesis.

Flexible females: nutritional state influences biparental cooperation in a burying beetle.

In species that provide biparental care, there is a sexual conflict between parents over how much each should contribute toward caring for their joint offspring. Theoretical models for the resolution of this conflict through behavioral negotiation between parents assume that parents cannot assess their partner's state directly but do so indirectly by monitoring their partner's contribution. Here, we test whether parents can assess their partner's state directly by investigating the effect of nutritional state on cooperation between parents in the burying beetle Nicrophorus vespilloides. We used a two-by-two factorial design, in which a well-fed or food-deprived female was paired with a well-fed or food-deprived male. We found that females adjusted their level of care in response to both their own nutritional state and that of their partner and that these decisions were independent of their partner's contribution. We found no evidence that males responded directly to the nutritional state. Males instead responded indirectly based on the contribution of their partner. Our results suggest that parents are able to assess the state of their partner, in contrast to what has been assumed, and that these assessments play an important role in the mediation of sexual conflict between caring parents.

Listening to the voices of mothers in Indonesia: Qualitative content analysis of experiences in parenting children with down syndrome.

INTRODUCTION: Generally, mothers provide the majority of caring for children who have Down syndrome. They pose challenges not only with regard to the acceptability of the child situation but also with regard to the provision of care for children with DS. AIM: To explore the experiences of mothers parenting children with DS in Indonesia, to give a better understanding of their needs, which is necessary for the delivery of treatment. METHODS: A descriptive qualitative research with content analysis was used. Study participants (15 mothers) were purposively sampled from attendees of a State Special School for students with disabilities. Data was collected via semi-structure interviews and were audio recorded. Participant's statements underwent content analysis, and the principle of trustworthiness was subsequently applied. RESULTS: Five main themes describing participants' experiences were identified: (1) parenting experiences - the impacts, (2) special needs, (3) parenting barriers, (4) parenting facilitators, and (5) mothers' expectations. CONCLUSIONS: The study findings showed that the mothers viewed their situation in both positive and negative ways. Despite the limited sample size in this exploratory study, the results offer new insights into raising a child with DS in a particular cultural setting. IMPLICATIONS FOR PRACTICE: This study offers important information to families and healthcare providers to improve awareness of the disorder and its appropriate management methods. It is important that an exploration of the experiences of mothers will provide healthcare professionals and families with an understanding of the situation. This understanding is essential for the effective management and delivery of treatment.

Reproductive biology of harvestmen (Arachnida: Opiliones): a review of a rapidly evolving research field.

Harvestmen are a major arachnid order that has experienced a dramatic increase in biological knowledge in the 21st century. The publication of the book Harvestmen: The Biology of Opiliones in 2007 stimulated the development of many behavioral studies. Although the book is relatively recent, our understanding of the reproductive biology of harvestmen is already outdated due to the fast accumulation of new data. Our goal is to provide an updated review of the subject to serve as a benchmark for the following years. In the pre-copulatory phase, we explore the evolution of facultative parthenogenesis, the factors that may affect the types of mating system, and the role of nuptial gifts in courtship. Regarding the copulatory phase, harvestmen are unique arachnids because they have aflagellate spermatozoa and a penis with complex morphology. We discuss the implications of these two features for sperm competition and cryptic female choice. In the post-copulatory phase, we connect oviposition site selection and climate conditions to the widespread occurrence of resource defense polygyny, alternative reproductive tactics, and sexual dimorphism in several clades of tropical harvestmen. Finally, we present the different forms of parental care in the order, and discuss the benefits and costs of this behavior, which can be performed either by females or males. Throughout the review, we indicate gaps in our knowledge and subjects that deserve further studies. Hopefully, the information synthesized here will stimulate researchers worldwide to embrace harvestmen as a study system and to improve our effort to unravel the mysteries of their reproductive biology.

Who is supporting the parents during their child's cancer treatment? A qualitative study through the lens of compassion.

PURPOSE: Parents of children/adolescents with cancer are placed in a state of severe suffering due to serious concerns, fears, and radical daily life changes. Human support is an important source of support for successful coping. This study explored fundamental aspects of parents' daily, social, and personal life during their child's treatment to deepen our understanding of 'who' plays a significant role in supporting parents, and how, and to what extent this support is provided. METHODS: This qualitative study was undertaken in a compassion paradigm, designed and guided by Heidegger's and Gadamer's philosophy and compassionate methods. Data were generated through ethnographic observations (144 h), focus group interviews (n = 2), and individual/couple interviews (n = 16) at two Danish hospitals. Inductive content analysis was used to analyse data. RESULTS: Overall, support from peers, health professionals, and social networks constituted significant sources of support. Especially peers and health professionals had a continuous support role, which was fundamental for establishing interpersonal closeness and relieving suffering. Sharing responsibilities between parents and among social networks seemed to ease the emotional and practical burden. However, to ensure effectiveness, social networks must be available, outreach, and responsive to needs. Moreover, parents disclosed little self-awareness and resources and options for self-care due to a combination of lack of awareness, time, and space in the hospitals. CONCLUSION: Safeguarding interpersonal and interparental understanding and closeness in parental care is essential. One way is building resilience and a broader human-to-human-based safety net around the family, including social networks and professional psychosocial support, advantageously using compassion.

Biological Links between Personality and Plasticity: Testing Some Alternative Hypotheses.

AbstractWhen organisms respond behaviorally to a stimulus, they exhibit plasticity, but some individuals respond to the same stimulus consistently differently than others, thereby also exhibiting personality differences. Parent house sparrows express individual differences in how often they feed offspring and how that feeding rate changes with nestling age. Mean feeding rate and its slope with respect to nestling age were positively correlated at median nestling ages but not at hatching, indicating that individuality is primarily in plasticity. Individual differences could arise because of (1) interactions between environmental variables, (2) differences in underlying state or "quality," or (3) differences in the ability to update cues of changing nestling demand. Individual slopes were modestly repeatable across breeding attempts, hinting at the likely action of additional environmental variables, but only brood size was important. I also found few correlates suggesting quality differences. I used short-term brood size manipulations at two nestling ages to test divergent predictions between the three hypotheses. The pattern of correlations between response to the manipulation and individual slope did not fit any single hypothesis. Patterns of sparrow parental care reveal that personality and plasticity are not cleanly separable, and their biology is likely intertwined. New thinking may be needed about the factors parents use in decisions about care and the relevant fitness consequences.

Effects of Parental Care on the Magnitude of Inbreeding Depression: A Meta-Analysis in Fishes.

AbstractInbreeding results from matings between relatives and often leads to a reduction in the fitness of inbred offspring, known as inbreeding depression. There is substantial variation in the magnitude of inbreeding depression among and within species, driven by differences in the biotic and abiotic environment. Recent studies in three species found that parental care has the potential to buffer against inbreeding depression in the offspring, but the generality of this pattern is still unknown. Here, we performed a meta-analysis to test whether variation in the magnitude of inbreeding depression is related to among-species differences in parental care in fishes. We synthesized 536 effect sizes across 56 studies and 18 species, spanning 47 years of research. We found that inbred offspring suffer a smaller reduction in fitness in species that provide biparental care than in species with uniparental or no care. By using a comparative approach, this study provides novel insights into the capacity of parental care to moderate inbreeding depression and suggests that these effects may currently be underappreciated. Considering the potential effects of parental care on inbreeding depression can help us understand why some species avoid inbreeding, whereas others tolerate or even prefer inbreeding, which has important implications for the maintenance of genetic variation within populations.

Evolution of parental care in haploid-diploid plants.

In bryophytes that alternate between haploid gametophytes and diploid sporophytes through sexual reproduction, sporophytes are often attached to and nurtured on the female gametophyte. A similar phenomenon is seen in Florideophyceae (a group of red algae). These systems in which a gametophyte (mother) invests nutrients in sporophytes (offspring) are ideal for studying the evolution of 'parental care' in non-animal organisms. Here, we propose a model of a haploid-diploid life cycle and examine the evolution of maternal investment in sporophytes focusing on two effects: the degree of paternal or maternal control of investment and the number of sporophytes. We find that when the female dominantly controls the investment, the evolutionarily stable level of investment is that which maximizes the expected reproductive success of the female gametophyte. The genomic conflict between maternal and paternal alleles complicates the evolutionary outcome; however, a greater male allelic effect and a higher number of sporophytes favour a higher energy investment, which may lead to evolutionary branching or run-away escalation of the investment level. This suggests that the selfishness of the paternal gene is the evolutionary driver of parental care and that complex structures such as fusion cells in red algae may have evolved to suppress it.

Plumage and eggshell colouration covary with the level of sex-specific parental contributions to nest building in birds.

Interspecific variation in sex-specific contributions to prenatal parental care, including avian nest building, is becoming increasingly better understood as we amass more information on more species. We examined whether sex-specific nest building contributions covary with the colouration of parents and their eggs in 521 species of Western Palearctic birds. Having colourful plumage and laying colourful eggs are costly because of the deposition of pigments in feathers and eggs and/or forming costly nanostructural substrates in feathers, and so it might be expected that those costs covary with the costs of nest building at the level of individuals and/or across species to produce of a suite of codivergent traits. Using a phylogenetically informed approach, we tested the hypothesis that species in which females alone invest energy building nests exhibit less sexual plumage dichromatism. However, we found comparative support for the opposite of this prediction. We then tested that species in which females alone build nests lay more colourful, and costlier, eggs because the dual costs of building nests and laying colourful eggs can only be borne by higher quality individuals. As expected, we found that species in which females build nests alone or together with males are more likely to lay colourfully pigmented eggs relative to species in which only males build nests. Finally, stochastic character mapping provided evidence of the repeated evolution of female-only nest building. Interspecific sex differences in plumage colouration therefore covary in a complex manner with female pre- (nest building) and post-copulatory (egg production) investment in reproduction.

Phenotypic plasticity in mass loss during chick rearing in the European starling (Sturnus vulgaris).

It has long been recognized that mass loss during breeding could be adaptive (e.g., by ameliorating the costs of increased parental activity). However, many studies still commonly interpret mass loss as evidence of "stress" or a cost of reproduction (i.e., a negative effect of high workload during chick provisioning). Despite several studies reporting evidence in support of both hypotheses, the ecological and/or life-history contexts under which mass loss may be viewed as a "cost" or an adaptive strategy are still unclear. Here, we used a long-term dataset from a breeding population of European starlings (Sturnus vulgaris) to investigate natural annual and individual variation in body mass and mass loss and to test whether mass loss during chick rearing represents a phenotypically plastic trait that varies predictably in relation to ecological context and individual quality. While there was significant annual variation in incubation mass, chick-rearing mass, and mass change, there were no systematic relationships between mass loss and current breeding success or future fecundity and survival. In addition, we found no evidence of intra-annual repeatability of mass loss between first and second broods ( = .00) but moderate interannual repeatability of mass loss (R = .61) during first broods, suggesting differences in mass loss under different selective pressures. However, we found no covariation between residual intra-individual variation in mass loss for first broods and other reproductive or life-history traits. We therefore found no support for the idea that mass loss reflects "reproductive stress" in our system: there were no negative relationships between mass loss and either current or future reproduction and survival (local return rate). Our results are consistent with mass loss being an individually plastic trait, with individuals using mass loss to "level the playing field" and individually optimize reproductive effort and fitness within their specific ecological context and relative to their individual quality for a given breeding attempt.