Trade-Offs Between Hepatic Host Defense and Metabolic Programs Underlie Sex-Biased Diseases

Current concepts in evolutionary medicine propose that trade-offs and mismatches with a shifting environment increase disease risk. While biological sex also impacts disease prevalence, contributions of environmental pressures to sex-biased diseases remain unexplored. Here, we show that sex-dependent hepatic programs confer a robust (~300%) survival advantage for male mice during lethal bacterial infection. The transcription factor BCL6, which masculinizes hepatic gene expression at puberty, is essential for this advantage. However, protection by BCL6 comes at a cost following dietary excess, resulting in overt fatty liver and glucose intolerance in males. Deleting hepatic BCL6 reverses these phenotypes but markedly lowers male fitness during infection, thus establishing a sex-dependent tradeoff between host defense and metabolic systems. We suggest that these tradeoffs, coupled with current environmental pressures, drive metabolic disease in males.

The Impact of Direct Challenges to Student Endorsement of Teleological Reasoning on Understanding and Acceptance of Natural Selection

Background: Teleological reasoning is a cognitive bias purported to disrupt student ability to understand natural selection. Few studies have described pedagogical efforts to decrease student endorsement of teleological reasoning and measure the effects of this attenuation on the understanding and acceptance of evolution. This study examined the influence of explicit instructional activities directly challenging student endorsement of teleological explanations for evolutionary adaptations on their learning of natural selection over a semester-long undergraduate course in evolutionary medicine. In a convergent mixed-methods design this study combined pre- and post-semester survey data (N = 83) on understanding natural selection, student endorsement of teleological reasoning, and acceptance of evolution, with thematic analysis of student reflective writing on their understanding and acceptance of natural selection and teleological reasoning.Results: Student endorsement of teleological reasoning decreased and understanding and acceptance of natural selection increased during a course on human evolution with teleological intervention (p£0.0001), compared to a control course. Endorsement of teleological reasoning was predictive of understanding of natural selection prior to the semester. Thematic analysis revealed that students were largely unaware of the concept of teleological reasoning prior to the course, but perceived attenuation of their own teleological reasoning by the end of the semester. Conclusions: Students are unaware of their high levels of endorsement of teleological reasoning upon entrance into the undergraduate human evolution course, which is consequential because teleological reasoning is a predicter of natural selection understanding. We developed class activities to directly challenge student endorsement of unwarranted design teleological reasoning. As a result, students had decreased unwarranted teleological reasoning and increased acceptance and understanding of natural selection over the course of the semester. The data presented show that students are receptive to explicit instructional challenges to their teleological reasoning and that attenuation of this bias is associated with gains in natural selection understanding and acceptance.

Evolutionary transcriptomics implicates new genes and pathways in human pregnancy and adverse pregnancy outcomes

Evolutionary changes in the anatomy and physiology of the female reproductive system underlie the origins and diversification of pregnancy in Eutherian ('Placental') mammals. This developmental and evolutionary history constrains normal physiological functions and biases the ways in which dysfunction contributes to reproductive trait diseases and adverse pregnancy outcomes. Here, we show that gene expression changes in the human endometrium during pregnancy are associated with the evolution of human-specific traits and pathologies of pregnancy. We found that hundreds of genes gained or lost endometrial expression in the human lineage. Among these are genes that may contribute to human-specific maternal-fetal communication (HTR2B) and maternal-fetal immunotolerance (PDCD1LG2) systems, as well as vascular remodeling and deep placental invasion (CORIN). These data suggest that explicit evolutionary studies of anatomical systems complement traditional methods for characterizing the genetic architecture of disease. We also anticipate our results will advance the emerging synthesis of evolution and medicine ('evolutionary medicine') and be a starting point for more sophisticated studies of the maternal-fetal interface. Furthermore, the gene expression changes we identified may contribute to the development of diagnostics and interventions for adverse pregnancy outcomes.

Overview of Research on Skeletal System And The Related Functional Structures Based on Evolutionary Medicine

The combination of evolutionary medicine and biomedicine is a breakthrough development direction in the field of medical research in recent years, and the connection between the occurrence and development of diseases of the skeletal system and its related functional structures and biological evolution has been a topic of discussion and research. In this paper, we systematically summarize the relevant domestic and foreign literature in this field over the past few years, from the theory of Darwinian medicine, clarify the research ideas of domestic and foreign scholars on the combination of diseases of the skeletal system and evolutionary medicine, review the mechanisms of related diseases that have been revealed, clarify the unique ideas of the current research methods and theories of scholars in this field that are different from traditional science, and then propose relevant reference theories for the clinical diagnosis and treatment of diseases of the skeletal system. We will present the relevant referential theories for the clinical management of skeletal system diseases to provide reference for further research.

Evolutionary medicine

In recognition that evolutionary theory is critical for understanding modern human health, eLife is publishing a special issue on evolutionary medicine to showcase recent research in this growing and increasingly interdisciplinary field.

Cognitive Behavior Therapy for Depression From an Evolutionary Perspective

Evolutionary medicine attempts to solve a problem with which traditional medicine has struggled historically; how do we distinguish between diseased states and “healthy” responses to disease states? Fever and diarrhea represent classic examples of evolved adaptations that increase the likelihood of survival in response to the presence of pathogens in the body. Whereas, the severe mental disorders like psychotic mania or the schizophrenias may involve true “disease” states best treated pharmacologically, most non-psychotic “disorders” that revolve around negative affects like depression or anxiety are likely adaptations that evolved to serve a function that increased inclusive fitness in our ancestral past. What this likely means is that the proximal mechanisms underlying the non-psychotic “disorders” are “species typical” and neither diseases nor disorders. Rather, they are coordinated “whole body” responses that prepare the individual to respond in a maximally functional fashion to the variety of different challenges that our ancestors faced. A case can be made that depression evolved to facilitate a deliberate cognitive style (rumination) in response to complex (often social) problems. What this further suggests is that those interventions that best facilitate the functions that those adaptations evolved to serve (such as rumination) are likely to be preferred over those like medications that simply anesthetize the distress. We consider the mechanisms that evolved to generate depression and the processes utilized in cognitive behavior therapy to facilitate those functions from an adaptationist evolutionary perspective.