Coloration and the Evolution of Live Birth

Organisms have a finite amount of energy with which to invest in survival, growth, and reproduction. Reproductive strategies can range from those that require minimal energy to produce eggs (oviparity) that then develop unassisted, those that require some energy to produce eggs that then hatch internally (ovoviviparity), and those that require significant energy to fully develop internally before birth (viviparity). Females of species that invest large amounts of energy to give birth to live young (viviparous species) may thus have more to lose in choosing low-quality mates than females of species that lay eggs (oviparous species). These females may therefore invest more energy in choosing high-quality males, increasing the competition between males for mates selecting for males with traits that advertise quality. Female choosiness is known to lead to more male-male competition and thus larger males, as well as more colorful and more ornamented males. Thus, we used coloration and body size as a proxy for female mate choice to investigate the correlation between female choosiness and the evolution of viviparity. However, oviparity and viviparity are nearly ubiquitous in birds and mammals, respectively, making it difficult to resolve questions about the evolution of viviparity. Squamate reptiles (lizards and snakes) present a unique opportunity to assess the evolution of live birth because viviparity appears to have evolved multiple times within these groups. Using phylogenetically controlled methods and a well-resolved but diverse group of squamate reptiles, we assessed whether the evolution of viviparity led to more colorful males across 248 species. For a subset of individuals for which sexual size dimorphism was quantified, we also determined whether the evolution of viviparity impacted the degree of size dimorphism. Finally, we determined the average estimated length of time required for males to evolve ornaments and estimated the rate of evolution of coloration across reptiles. These data are important for understanding the evolution of color across multiple groups of animals, as well as for understanding the consequences of viviparity in endothermic groups such as mammals. For example, viviparous lineages have significantly higher speciation and extinction rates than oviparous lineages, and our study suggests that sexual selection for male colorfulness may be one of the drivers of these high rates

No apparent benefits of allonursing for recipient offspring and mothers in the cooperatively breeding meerkat.

Cooperative behaviours by definition are those that provide some benefit to another individual. Allonursing, the nursing of non-descendent young, is often considered a cooperative behaviour and is assumed to provide benefits to recipient offspring in terms of growth and survival, and to their mothers, by enabling them to share the lactation load. However, these proposed benefits are not well understood, in part because maternal and litter traits and other ecological and social variables are not independent of one another, making patterns hard to discern using standard univariate analyses. Here, we investigate the potential benefits of allonursing in the cooperatively breeding Kalahari meerkat, where socially subordinate females allonurse the young of a dominant pair without having young of their own. We use structural equation modelling to allow us to account for the interdependence of maternal traits, litter traits and environmental factors. We find no evidence that allonursing provides benefits to pups or mothers. Pups that received allonursing were not heavier at emergence and did not have a higher survival rate than pups that did not receive allonursing. Mothers whose litters were allonursed were not in better physical condition, did not reconceive faster and did not reduce their own nursing investment compared to mothers who nursed their litters alone. These patterns were not significantly influenced by whether mothers were in relatively good, or poor, condition. We suggest that allonursing may persist in this species because the costs to allonurses may be low. Alternatively, allonursing may confer other, more cryptic, benefits to pups or allonurses, such as immunological or social benefits.KJM was supported by a research grant from the Cambridge Philosophical Society. KEM was supported by a US National Science Foundation grant to Alison Bell and KEM (NSF IOS 1121980).This is the accepted manuscript. The final version is available at http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12343/abstract

Social context-dependent provisioning rules in red-winged fairy-wrens do not vary with signals of increased chick need

Individuals should adjust investment in parental care in order to maximize current and future reproductive success. In cooperative breeders, where helpers assist with raising offspring, larger groups may allow for a reduction in investment (load lightening) of each individual. Additionally, the type of individual, and thus the social context, can play an important role in individual investment. Less attention has been paid to how provisioning rules vary across ecological contexts, although theory suggests that individuals can only afford to reduce their investment when nestling starvation is unlikely, thus under mild conditions. Here, we tested whether previously reported provisioning rules based on social context vary with ecological conditions, by experimental manipulation of signals of chick need, in the cooperatively breeding red-winged fairy-wren, Malurus elegans. Previous work in this species has shown that all group members load-lighten with additional male helpers, but not in response to the number of female helpers in the group (additive care). We show that experimental begging playback resulted in all individuals increasing their provisioning rates, indicating that our treatment was perceived as increased chick need. However, in contrast to our prediction that load lightening should only occur when individuals can afford to do so, signals of increased chick need did not stop individuals from reducing their investment with an increasing number of male helpers in the group. These results suggest that despite some flexibility in parental effort, individuals use strict rules with respect to group composition, suggesting that individual provisioning effort is based on multiple integrated cues, and responses to changes in the environment are highly context dependent.This work was supported by an Association for the Study of Animal Behaviour research grant to K.J.M., and by an Australian Research Council DECRA fellowship to L.B. (DE130100174)

Do mothers bias offspring sex ratios in carotenoid-rich environments?

If environmental or maternal factors favor the fitness of one sex over the other, theory predicts that mothers should produce more offspring of the sex most likely to benefit from prevailing conditions. For species where males depend on carotenoid-based colorful ornaments to secure territory or attract mates, carotenoid availability in the environment could be one such component: mothers experiencing high availability of carotenoids should produce more sons. Here, we test this hypothesis by providing carotenoids to a wild population of a sexually dimorphic passerine, the hihi (stitch bird: Notiomystis cincta). Access to carotenoids during early life influences the color of male hihi plumage, which improves territory acquisition as adults. Therefore, carotenoid availability when young may influence male fitness. However, we found no evidence of sex ratio bias in treated or untreated groups, either before or after hatching. First-laid eggs, where carotenoid concentrations are usually highest, were also unbiased. For hihi, access to carotenoids during egg laying does not appear to encourage mothers to alter sex ratios of offspring. Alternatively, the fitness of daughters may also benefit from increased carotenoids during development. Disentangling these alternatives requires further work

The influence of maternal glucocorticoids on offspring phenotype in high-and low-risk environments

Elevated maternal glucocorticoid levels during gestation can lead to phenotypic changes in offspring via maternal effects. Although such effects have traditionally been considered maladaptive, maternally derived glucocorticoids may adaptively prepare offspring for their future environment depending upon the correlation between maternal and offspring environments. Nevertheless, relatively few studies test the effects of prenatal glucocorticoid exposure across multiple environments. We tested the potential for ecologically relevant increases in maternal glucocorticoids in the eastern fence lizard (Sceloporus undulatus) to induce adaptive phenotypic changes in offspring exposed to high or low densities of an invasive fire ant predator. Maternal treatment had limited effects on offspring morphology and behavior at hatching, but by 10 days of age, we found maternal treatment interacted with offspring environment to alter anti-predator behaviors. We did not detect differences in early-life survival based on maternal treatment or offspring environment. Opposing selection on anti-predator behaviors from historic and novel invasive predators may confound the potential of maternal glucocorticoids to adaptively influence offspring behavior. Our test of the phenotypic outcomes of transgenerational glucocorticoid effects across risk environments provides important insight into the context-specific nature of this phenomenon and the importance of understanding both current and historic evolutionary pressures

Increasing uptake of hepatitis C virus infection case- finding, testing, and treatment in primary care: evaluation of the HepCATT (Hepatitis C Assessment Through to Treatment) trial

Background Hepatitis C virus (HCV) infection is a key cause of liver disease but can be cured in more than 95% of patients. Around 70 000 people in England may have undiagnosed HCV infection and many more will not have been treated. Interventions to increase case-finding in primary care are likely to be cost-effective; however, evidence of effective interventions is lacking. The Hepatitis C Assessment Through to Treatment (HepCATT) trial assessed whether a complex intervention in primary care could increase case-finding, testing, and treatment of HCV.Aim To investigate the feasibility and acceptability of the HepCATT intervention.Design and setting A qualitative study with primary care practice staff from practices in the south west of England taking part in the HepCATT trial.Method Semi-structured interviews were carried out with GPs, nurses, and practice staff to ascertain their views of the HepCATT intervention at least 1 month after implementing the intervention in their practice. Normalisation process theory, which outlines the social processes involved in intervention implementation, informed thematic data analysis.Results Participants appreciated the HepCATT intervention for increasing knowledge and awareness of HCV. Although some initial technical difficulties were reported, participants saw the benefits of using the audit tool to systematically identify patients with HCV infection risk factors and found it straightforward to use. Participants valued the opportunity to discuss HCV testing with patients, especially those who may not have been previously aware of HCV risk. Future implementation should consider fully integrating software systems and additional resources to screen patient lists and conduct tests.Conclusion When supported by a complex intervention, primary care can play a crucial role in identifying and caring for patients with HCV infection, to help stem the HCV epidemic, and prevent HCV-related illnes

Increasing uptake of Hepatitis C virus infection case-finding, testing and treatment in primary care:HepCATT (Hepatitis C Assessment Through to Treatment Trial) qualitative evaluation

Hepatitis C virus (HCV) infection is a key cause of liver disease but can be cured in more than 95% of patients. Around 70 000 people in England may have undiagnosed HCV infection and many more will not have been treated. Interventions to increase case-finding in primary care are likely to be cost-effective; however, evidence of effective interventions is lacking. The Hepatitis C Assessment Through to Treatment (HepCATT) trial assessed whether a complex intervention in primary care could increase case-finding, testing, and treatment of HCV

A randomised controlled trial comparing opt-in and opt-out home visits for tracing lost participants in a prospective birth cohort study

© 2015 Bray et al. Background: Attrition is an important problem in cohort studies. Tracing cohort members who have moved or otherwise lost contact with the study is vital. There is some debate about the acceptability and relative effectiveness of opt-in versus opt-out methods of contacting cohort members to re-engage them in this context. We conducted a randomised controlled trial to compare the two approaches in terms of effectiveness (tracing to confirm address and consenting to continue in the study), cost-effectiveness and acceptability. Methods: Participants in this trial were individuals (young people and mothers) recruited to the Avon Longitudinal Study of Parents and Children (ALSPAC), who had not engaged with the study in the previous 5 years and for whom mail had been returned from their last known address. The sampling frame was restricted to those for whom database searching led to a potential new address being found in the Bristol area. 300 participants were randomly selected and assigned using stratified randomisation to the opt-in or opt-out arm. A tailored letter was sent to the potential new address, either asking participants to opt in to a home visit, or giving them the option to opt out of a home visit. Fieldworkers from Ipsos MORI conducted home visits to confirm address details. Results: The proportion who were traced was higher in the opt-out arm (77/150∈=∈51 %) than the opt-in arm (6/150∈=∈4 %), as was the proportion who consented to continue in ALSPAC (46/150∈=∈31 % v 4/150∈=∈3 %). The mean cost per participant was £8.14 in the opt-in arm and £71.93 in the opt-out arm. There was no evidence of a difference in acceptability between the opt-in and opt-out approaches. Conclusion: Since the opt-in approach yielded very low response rates, and there were no differences in terms of acceptability, we conclude that the opt-out approach is the most effective method of tracing disengaged study members. The gains made in contacting participants must be weighed against the increase in cost using this methodology

Hepatitis C – Assessment to Treatment Trial (HepCATT) in primary care:study protocol for a cluster randomised controlled trial

BACKGROUND: Public Health England (PHE) estimates that there are upwards of 160,000 individuals in England and Wales with chronic hepatitis C virus (HCV) infection, but until now only around 100,000 laboratory diagnoses have been reported to PHE and of these 28,000 have been treated. Targeted case-finding in primary care is estimated to be cost-effective; however, there has been no robust randomised controlled trial evidence available of specific interventions. Therefore, this study aims to develop and conduct a complex intervention within primary care and to evaluate this approach using a cluster randomised controlled trial. METHODS/DESIGN: A total of 46 general practices in South West England will be randomised in a 1:1 ratio to receive either a complex intervention comprising: educational training on HCV for the practice; poster and leaflet display in the practice waiting rooms to raise awareness and encourage opportunistic testing; a HCV risk prediction algorithm based on information on possible risk markers in the electronic patient record run using Audit + software (BMJ Informatica). The audit will then be used to recall and offer patients a HCV test. Control practices will follow usual care. The effectiveness of the intervention will be measured by comparing number and rates of HCV testing, the number and proportion of patients testing positive, onward referral, rates of specialist assessment and treatment in control and intervention practices. Intervention costs and health service utilisation will be recorded to estimate the NHS cost per new HCV diagnosis and new HCV patient initiating treatment. Longer-term cost-effectiveness of the intervention in improving quality-adjusted life years (QALYs) will be extrapolated using a pre-existing dynamic health economic model. Patients' and health care workers' experiences and acceptability of the intervention will be explored through semi-structured qualitative interviews. DISCUSSION: This trial has the potential to make an important impact on patient care and will provide high-quality evidence to help general practitioners make important decisions on HCV testing and onward referral. If found to be effective and cost-effective the intervention is readily scalable and can be used to support the implementation of NICE recommendations on HCV case-finding. TRIAL REGISTRATION: ISRCTN61788850 . Registered on 24 April 2015; Protocol Version: 2.0, 22 May 2015

A lower to middle Eocene astrochronology for the Mentelle Basin (Australia) and its implications for the geologic time scale

The geologic time scale for the Cenozoic Era has been notably improved over the last decades by virtue of integrated stratigraphy, combining high-resolution astrochronologies, biostratigraphy and magnetostratigraphy with high-precision radioisotopic dates. However, the middle Eocene remains a weak link. The so-called “Eocene time scale gap” reflects the scarcity of suitable study sections with clear astronomically-forced variations in carbonate content, primarily because large parts of the oceans were starved of carbonate during the Eocene greenhouse. International Ocean Discovery Program (IODP) Expedition 369 cored a carbonate-rich sedimentary sequence of Eocene age in the Mentelle Basin (Site U1514, offshore southwest Australia). The sequence consists of nannofossil chalk and exhibits rhythmic clay content variability. Here, we show that IODP Site U1514 allows for the extraction of an astronomical signal and the construction of an Eocene astrochronology, using 3-cm resolution X-Ray fluorescence (XRF) core scans. The XRF-derived ratio between calcium and iron content (Ca/Fe) tracks the lithologic variability and serves as the basis for our U1514 astrochronology. We present a 16 million-year-long (40-56 Ma) nearly continuous history of Eocene sedimentation with variations paced by eccentricity and obliquity. We supplement the high-resolution XRF data with low-resolution bulk carbon and oxygen isotopes, recording the long-term cooling trend from the Paleocene-Eocene Thermal Maximum (PETM – ca. 56 Ma) into the middle Eocene (ca. 40 Ma). Our early Eocene astrochronology corroborates existing chronologies based on deep-sea sites and Italian land sections. For the middle Eocene, the sedimentological record at U1514 provides a single-site geochemical backbone and thus offers a further step towards a fully integrated Cenozoic geologic time scale at orbital resolution