Mechanisms of equality and inequality in mammalian societies.

The extent of (in)equality is highly diverse across species of social mammals, but we have a poor understanding of the factors that produce or inhibit equitable social organizations. Here, we adopt a comparative evolutionary perspective to test whether the evolution of social dominance hierarchies, a measure of social inequality in animals, exhibits phylogenetic conservatism and whether interspecific variation in these traits can be explained by sex, age or captivity. We find that hierarchy steepness and directional consistency evolve rapidly without any apparent constraint from evolutionary history. Given this extraordinary variability, we next consider multiple factors that have evolved to mitigate social inequality. Social networks, coalitionary support and knowledge transfer advantage to privilege some individuals over others. Nutritional access and prenatal stressors can impact the development of offspring, generating health disparities with intergenerational consequences. Intergenerational transfer of material resources (e.g. stone tools, food stashes, territories) advantage those who receive. Nonetheless, many of the same social species that experience unequal access to food (survival) and mates (reproduction) engage in levelling mechanisms such as food sharing, adoption, revolutionary coalitions, forgiveness and inequity aversion. Taken together, mammals rely upon a suite of mechanisms of (in)equality to balance the costs and benefits of group living. This article is part of the theme issue 'Evolutionary ecology of inequality'.

Galectin-3 is Associated with Heart Failure Incidence: A Meta-Analysis.

INTRODUCTION: Heart failure (HF) is a leading cause of death worldwide. The global prevalence of heart failure is projected to increase rapidly in the coming decades, and significant attention has turned to improving biomarker-based risk prediction of incident HF. This paper aimed to qualitatively and quantitatively evaluate the evidence associating levels of galectin-3 with the risk of incident HF. METHODS: A review of PUBMED-indexed peer-reviewed literature was performed. Nine studies met the inclusion criteria, and all nine had data eligible for conversion and pooling. A randomeffects meta-analysis was performed using hazard ratios and 95% confidence intervals from a minimally adjusted model, a further adjusted model, and from subgroups within the further-adjusted model. RESULTS: The minimally-adjusted model provided an HR of 1.97 (95% CI 1.74-2.23) when comparing the top quartile of log-gal-3 to the bottom quartile. The further-adjusted model provided an HR of 1.32 (95% CI 1.21-1.44) for the same comparison. The positive, significant association was conserved during sensitivity analysis. CONCLUSION: There is a significant positive association between circulating galectin-3 and the risk of incident heart failure. Given the complex mechanistic relationship between galectin-3 and cardiovascular pathophysiology, further investigation is recommended for the possible implementation of galectin-3 into clinical risk prediction models.

Did giraffe cardiovascular evolution solve the problem of heart failure with preserved ejection fraction?

The evolved adaptations of other species can be a source of insight for novel biomedical innovation. Limitations of traditional animal models for the study of some pathologies are fueling efforts to find new approaches to biomedical investigation. One emerging approach recognizes the evolved adaptations in other species as possible solutions to human pathology. The giraffe heart, for example, appears resistant to pathology related to heart failure with preserved ejection fraction (HFpEF)-a leading form of hypertension-associated cardiovascular disease in humans. Here, we postulate that the physiological pressure-induced left ventricular thickening in giraffes does not result in the pathological cardiovascular changes observed in humans with hypertension. The mechanisms underlying this cardiovascular adaptation to high blood pressure in the giraffe may be a bioinspired roadmap for preventive and therapeutic strategies for human HFpEF.

Manipulating the exposome to enable better ageing.

The sum total of life course exposures creates an exposome that has a significant impact on age-related health. Understanding the interplay between exposome factors and the (epi) genome, offers pertinent insights into the ageing process and its relationship with the accumulation of allostatic load. We propose to exploit this to develop a biomimetic approach that will provide insight into how evolution through natural selection in other species has solved many age related human health issues. In particular, we will emphasise the need to reconnect a more mechanistic approach to medical science with a broader natural sciences approach, using biomimetics to mitigate the global burden of age related ill health. In particular, we will discuss how such an approach indicates leverage of the activities of the Nrf 2 gene to enhance health span via reintroduction of the classical 'Food as Medicine' concept, including modulation of the microbiome and the creation of more salutogenic and biophilic environments. Additionally, we will discuss how this approach integrates with novel and developing senotherapies.

History of the National Academies of Sciences, Engineering, and Medicine's Institute for Laboratory Animal Research.

The Institute for Laboratory Animal Research (ILAR) was created within the National Academies of Sciences, Engineering, and Medicine (National Academies) in 1953 when biomedical research using animals was in its infancy in terms of quantity, quality, complexity, sophistication, and care. Over the intervening 69 years, ILAR has witnessed unprecedented growth, followed by unprecedented decline, and then regrowth in usage of specific species and models and an overall shift in experimental burden away from larger to smaller species (ie, mice, fish, and rats). ILAR has contributed much to the evolution of necessary research using animals and animal models for the benefit of humans, animals, and the environment and to the development and implementation of humane principles and standards for care and use of research animals. ILAR has served as a "neutral broker" seeking consensus, solutions, common ground, and pathways forward for all professional constituencies engaged in conduct of animal research. In 2022, ILAR will become the Board on Animal Health Sciences, Conservation, and Research (BAHSCR) within the Division on Earth and Life Studies of the National Academies and the ILAR Journal will pause publication with volume 62. This manuscript recounts the history and accomplishments of ILAR 1953-2022, emphasizing the past 2 decades. The manuscript draws upon ILAR's communications and previously published histories to document ILAR's leaders, reports, publications, conferences, workshops, and roundtables using text, tables, references, and extensive supplemental tables. The authors' intention is to provide the scientific community with a single source document for ILAR, and they apologize for any omissions and errors.

A cross-species approach to disorders affecting brain and behaviour.

Structural and functional elements of biological systems are highly conserved across vertebrates. Many neurological and psychiatric conditions affect both humans and animals. A cross-species approach to the study of brain and behaviour can advance our understanding of human disorders via the identification of unrecognized natural models of spontaneous disorders, thus revealing novel factors that increase vulnerability or resilience, and via the assessment of potential therapies. Moreover, diagnostic and therapeutic advances in human neurology and psychiatry can often be adapted for veterinary patients. However, clinical and research collaborations between physicians and veterinarians remain limited, leaving this wealth of comparative information largely untapped. Here, we review pain, cognitive decline syndromes, epilepsy, anxiety and compulsions, autoimmune and infectious encephalitides and mismatch disorders across a range of animal species, looking for novel insights with translational potential. This comparative perspective can help generate novel hypotheses, expand and improve clinical trials and identify natural animal models of disease resistance and vulnerability.

Incorporating one health into medical education.

One Health is an emerging concept that stresses the linkages between human, animal, and environmental health, as well as the need for interdisciplinary communication and collaboration to address health issues including emerging zoonotic diseases, climate change impacts, and the human-animal bond. It promotes complex problem solving using a systems framework that considers interactions between humans, animals, and their shared environment. While many medical educators may not yet be familiar with the concept, the One Health approach has been endorsed by a number of major medical and public health organizations and is beginning to be implemented in a number of medical schools. In the research setting, One Health opens up new avenues to understand, detect, and prevent emerging infectious diseases, and also to conduct translational studies across species. In the clinical setting, One Health provides practical ways to incorporate environmental and animal contact considerations into patient care. This paper reviews clinical and research aspects of the One Health approach through an illustrative case updating the biopsychosocial model and proposes a basic set of One Health competencies for training and education of human health care providers.

A Systematic Review of Carrion Eaters' Adaptations to Avoid Sickness.

Species that scavenge on dead animals are exposed to enhanced disease risks. Eight hypotheses have been suggested to explain how scavengers avoid becoming sick from their diet. We conducted a systematic review of the literature and found correlative support for four of the eight hypotheses but limited evidence of systematic studies of the hypotheses. We found no support that using urine to sterilize carcasses, having bald heads, eating rapidly, or food-washing behavior reduced disease risk in carrion eaters. With the exception of food washing, none of these hypotheses have been properly evaluated as an adaptation to avoid sickness from carrion. There is some support for having a specialized microbiome, having enhanced immunologic defenses, avoiding rotten food, and maintaining a low gastric pH to eliminate pathogens. Specialized immunologic defenses and having a low pH have the most support, but the diversity of mechanisms suggests that there is a great opportunity for even more detailed study. Increased knowledge in these mechanisms may provide biomimetic insights to help combat foodborne illnesses and enhance health.

Evolutionary determinants of polycystic ovary syndrome: part 2.

Polycystic ovary syndrome (PCOS) is a prehistoric complex genetic trait, perhaps dating back at least 50,000 years. The disorder also represents an evolutionary paradox, demonstrating clear reproductive disadvantages (i.e., lack of evolutionary fitness), albeit persisting tens of thousands of years. Here we examine possible explanations for this paradox. We evaluate a variety of possible benefits accruing to women in ancestral populations who possessed this trait, including considerations of whether dramatic changes in environment and lifestyle from the ancestral past to the contemporary present have altered the selection dynamics operating on the trait. Putative benefits include metabolic functioning, immune system dynamics, patterns of child-rearing and mothering, reproductive longevity, in utero or childhood survival, and musculoskeletal advantages. However, there is limited evidence that the persistence and relative homogeneity in the prevalence of PCOS can be accounted for by direct positive selection. Rather, PCOS evolution has likely been driven by nonadaptive evolutionary mechanisms, including genetic drift due to a serial founder effect and population balance due to sexually antagonistic selection. Ultimately, insights into the evolutionary origins of PCOS will emerge through the study not only of unique characteristics of affected individuals and their environments butalso through a broad consideration of the potential adaptive and beneficial aspects of vulnerability to the disorder, importantly including examination of populations whose fertility, disease load, and diet resemble those of ancestral humans.

The evolution of capture myopathy in hooved mammals: a model for human stress cardiomyopathy?

BACKGROUND AND OBJECTIVES: Capture myopathy (CM) syndromes in wildlife may be a model for human stress cardiomyopathy, including Takotsubo cardiomyopathy. Emotional stress or grief may trigger heart attack-like symptoms, and occasionally, sudden death in some humans. Similarly, wildlife exposed to predatory stresses, chase, or capture occasionally results in sudden death. To better understand the nature of vulnerability to stress-induced sudden death, we studied cases of CM in hooved mammals-ungulates-and hypothesized that CM would be associated with a syndrome of longevity-related traits. METHODOLOGY: We reconstructed the evolution of CM in ungulates then determined how a set of life history traits explained variation in the likelihood that CM was reported. RESULTS: CM is broadly reported, but not in all genera, and phylogenetic analyses suggest that it is an evolutionarily labile trait. We found that the following traits were significantly associated with reports of CM: greater brain mass, faster maximum running speed, greater minimum group size and greater maximum longevity. CONCLUSIONS AND IMPLICATIONS: CM may be an unavoidable consequence of adaptations to reduce predation risk that include increased running speed, sociality and having larger brains. Moreover, longer-lived species seem to be more likely to be susceptible to CM. Exploring variable susceptibility to CM highlights the evolutionary origins of the disorder, potential basic mechanisms that underlie vulnerability to the phenomenon, and the potential for reduction of risk through modification of life history trajectory.

A Physician's View of One Health: Challenges and Opportunities.

One Health is one of the most important movements and emerging concepts in health today. The convergence of the fields of human and animal medicine has the potential to generate novel scientific hypotheses, create effective new therapies and potentially transform how physicians, veterinarians and their patients understand health and disease. Despite this potential, One Health has not yet gained significant awareness or traction in human medical communities. From its inception, One Health, sometimes also called One Medicine, has been piloted primarily by leaders from the world of veterinary medicine. Although the specific term was coined perhaps 10 years ago, comparative medicine has been quietly evident on university campuses with veterinary and medical schools for decades longer. Although a few physicians have played major leadership roles in One Health, in the United States, despite over ten years of the movement's robust growth, many have still not heard of it. Furthermore, physicians with some awareness of One Health often believe it to be primarily and exclusively about zoonotic infections and global health. The much broader scope and potential of One Health as also including comparative physiology and medicine is not being communicated effectively. Consequently, the human medical community remains largely disengaged. This is problematic because without significant engagement from physicians, nurses and other human health care professionals, the potential of One Health cannot be realized. To advance One Health it is imperative that we first understand the roots of under-engagement of the human medical community. This, in turn, can guide the development of novel and engaging opportunities for physician which demonstrate the power relevance of One Health's comparative, collaborative and cooperative approach.[...].