The origin of species remains a central question, and recent research focuses on the role of ecological differences in promoting speciation. Ecological differences create opportunities for divergent selection (i.e. 'ecological' speciation), a Darwinian hypothesis that hardly requires justification. In contrast, 'mutation-order' speciation proposes that, instead of adapting to different environments, populations find different ways to adapt to similar environments, implying that speciation does not require ecological differences. This distinction is critical as it provides an alternative hypothesis to the prevailing view that ecological differences drive speciation. Speciation by sexual selection lies at the centre of debates about the importance of ecological differences in promoting speciation; here, we present verbal and mathematical models of mutation-order divergence by sexual selection. We develop three general cases and provide a two-locus population genetic model for each. Results indicate that alternative secondary sexual traits can fix in populations that initially experience similar natural and sexual selection and that divergent traits and preferences can remain stable in the face of low gene flow. This stable divergence can facilitate subsequent divergence that completes or reinforces speciation. We argue that a mutation-order process could explain widespread diversity in secondary sexual traits among closely related, allopatric species.

There is a paucity of data to support evidence-based practices in the provision of patient/family education in the context of a new childhood cancer diagnosis. Since the majority of children with cancer are treated on pediatric oncology clinical trials, lack of effective patient/family education has the potential to negatively affect both patient and clinical trial outcomes. The Children’s Oncology Group Nursing Discipline convened an interprofessional expert panel from within and beyond pediatric oncology to review available and emerging evidence and develop expert consensus recommendations regarding harmonization of patient/family education practices for newly diagnosed pediatric oncology patients across institutions. Five broad principles, with associated recommendations, were identified by the panel, including recognition that (1) in pediatric oncology, patient/family education is family-centered; (2) a diagnosis of childhood cancer is overwhelming and the family needs time to process the diagnosis and develop a plan for managing ongoing life demands before they can successfully learn to care for the child; (3) patient/family education should be an interprofessional endeavor with 3 key areas of focus: (a) diagnosis/treatment, (b) psychosocial coping, and (c) care of the child; (4) patient/family education should occur across the continuum of care; and (5) a supportive environment is necessary to optimize learning. Dissemination and implementation of these recommendations will set the stage for future studies that aim to develop evidence to inform best practices, and ultimately to establish the standard of care for effective patient/family education in pediatric oncology.

Recent studies show that epigenetic variation in the form of DNA methylation may serve as a substrate for selection. Theory suggests that heritable epigenetic marks that increase fitness should increase in frequency in a population, and these changes may result in novel morphology, behaviour, or physiology, and ultimately reproductive isolation. Therefore, epigenetic variation might provide the first substrate for selection during the course of evolutionary divergence. This hypothesis predicts that populations in the earliest stages of divergence will differentiate in their methylome prior to any genetic differentiation. While several studies have investigated natural epigenetic variation, empirical studies that test predictions about its role in speciation are surprisingly scarce. Here, we investigate DNA methylation variation using an isoschizomeric digest method, Methyl-Sensitive Amplified Polymorphism, across multiple stages of evolutionary divergence in natural populations of North American stream fishes. We show that epigenetic differentiation between methylomes is greater than genetic divergence among closely related populations across two river drainages. Additionally, we demonstrate that epigenetic divergence is a stronger predictor of the strength of behavioural reproductive isolation and suggest that changes in the methylome could influence the evolution of reproductive isolation between species. Our findings suggest a role for epigenetics not only in the initiation of divergence, but also in the maintenance of species boundaries over greater evolutionary timescales.

Providing psychosocial support to parents whose infants are hospitalized in the neonatal intensive care unit (NICU) can improve parents' functioning as well as their relationships with their babies. Yet, few NICUs offer staff education that teaches optimal methods of communication with parents in distress. Limited staff education in how to best provide psychosocial support to families is one factor that may render those who work in the NICU at risk for burnout, compassion fatigue and secondary traumatic stress syndrome. Staff who develop burnout may have further reduced ability to provide effective support to parents and babies. Recommendations for providing NICU staff with education and support are discussed. The goal is to deliver care that exemplifies the belief that providing psychosocial care and support to the family is equal in importance to providing medical care and developmental support to the baby.

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