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1. The cultural evolution of witchcraft beliefs

   https://doi.org/10.1016/j.evolhumbehav.2024.106610  

   Peacey, Sarah; Wu, Baihui; Grollemund, Rebecca; Mace, Ruth (July 2024, Evolution and Human Behavior)

   Witchcraft beliefs are historically and geographically widespread, but little is known about the cultural inheritance processes that may explain their variation between populations. A core component of witchcraft belief is that certain people (‘witches’) are thought to harm others using supernatural means. Various traits, which we refer to as the ‘witchcraft phenotype’ accompany these beliefs. Some can be classified as ‘symbolic culture’, including ideas about the typical behaviour of witches and concepts such as familiars (witches’ magical helpers), and demographic traits such as the age and sex of those likely to be accused. We conducted an exploratory study of the cultural evolution of 31 witchcraft traits to examine their inferred ancestry and associations with historic population movements. We coded a dataset from ethnographic accounts of Bantu and Bantoid-speaking societies in sub-Saharan Africa (N = 84) and analysed it using phylogenetic comparative methods (PCMs). Our results estimate that while some traits, such as an ordeal to test for witchcraft, have deep history, others, such as accusations of children, may have evolved more recently, or are limited to specific clusters of societies. Demographic and symbolic cultural traits do not typically co-evolve. Our findings suggest traits have different transmission patterns, and these may result from benefits they provide or from universal psychological mechanisms that produce their recurrent evolution. 

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2. Population structure drives cultural diversity in finite populations: A hypothesis for localized community patterns on Rapa Nui (Easter Island, Chile)

   https://doi.org/10.1371/journal.pone.0250690  

   Lipo, Carl P.; DiNapoli, Robert J.; Madsen, Mark E.; Hunt, Terry L. (May 2021, PLOS ONE)

   Esteve-Altava, Borja (Ed.)

   Understanding how and why cultural diversity changes in human populations remains a central topic of debate in cultural evolutionary studies. Due to the effects of drift, small and isolated populations face evolutionary challenges in the retention of richness and diversity of cultural information. Such variation, however, can have significant fitness consequences, particularly when environmental conditions change unpredictably, such that knowledge about past environments may be key to long-term persistence. Factors that can shape the outcomes of drift within a population include the semantics of the traits as well as spatially structured social networks. Here, we use cultural transmission simulations to explore how social network structure and interaction affect the rate of trait retention and extinction. Using Rapa Nui (Easter Island, Chile) as an example, we develop a model-based hypothesis for how the structural constraints of communities living in small, isolated populations had dramatic effects and likely led to preventing the loss of cultural information in both community patterning and technology. 

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3. Population Genomics of Premature Termination Codons in Cavefish With Substantial Trait Loss

   https://doi.org/10.1093/molbev/msaf012  

   Roback, Emma_Y; Ferrufino, Estephany; Moran, Rachel_L; Shennard, Devin; Mulliniks, Charlotte; Gallop, Josh; Weagley, James; Miller, Jeffrey; Fily, Yaouen; Ornelas-García, Claudia_Patricia; et al (January 2025, Molecular Biology and Evolution)

   Abstract Loss-of-function alleles are a pertinent source of genetic variation with the potential to contribute to adaptation. Cave-adapted organisms exhibit striking loss of ancestral traits such as eyes and pigment, suggesting that loss-of-function alleles may play an outsized role in these systems. Here, we leverage 141 whole genome sequences to evaluate the evolutionary history and adaptive potential of single nucleotide premature termination codons (PTCs) in Mexican tetra. We find that cave populations contain significantly more PTCs at high frequency than surface populations. We also find that PTCs occur more frequently in genes with inherent relaxed evolutionary constraint relative to the rest of the genome. Using SLiM to simulate PTC evolution in a cavefish population, we show that the smaller population size and increased genetic drift is sufficient to account for the observed increase in PTC frequency in cave populations without positive selection. Using CRISPR-Cas9, we show that mutation of one of these genes, pde6c, produces phenotypes in surface Mexican tetra that mimic cave-derived traits. Finally, we identify a small subset of candidate genes that contain high-frequency PTCs in cave populations, occur within selective sweeps, and may contribute to beneficial traits such as reduced energy expenditure, suggesting that a handful of PTCs may be adaptive. Overall, our work provides a rare characterization of PTCs across wild populations and finds that they may have an important role in loss-of-function phenotypes, contributing to a growing body of literature showing genome evolution through relaxed constraint in subterranean organisms. 

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4. Individual dietary specialization in a generalist bee varies across populations but has no effect on the richness of associated microbial communities

   https://doi.org/10.1086/721023  

   Gaiarsa, Marilia Palumbo; Rehan, Sandra; Barbour, Matthew A.; McFrederick, Quinn S. (May 2022, The American Naturalist)

   Despite the increasingly documented occurrence of individual specialization, the relationship between individual consumer interactions and diet-related microbial communities in wild populations is still unclear. Using data from nests of the bee Ceratina australensis from three different wild populations, we combine metabarcoding and network approaches to explore the existence of individual variation in resource use within and across populations, and whether dietary specialization affects the richness of pollen-associated microbes. We reveal the existence of marked dietary specialization. In the most specialized population, we also show that individuals' diet breadth was positively related to the richness of fungi, but not bacteria. Overall, individual specialization appeared to have a weak or negligible effect on the microbial richness of nests, suggesting that different mechanisms beyond environmental transmission may be at play regarding microbial acquisition in wild bees. 

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5. Reclaiming Our Identity Through Indigenous Cultural Generative Acts to Improve Mental Health of All Generations

   Lewis, J (May 2022, Springer Publishing)

   Danto, D; Zangeneh, M (Ed.)

   “Generativity” represents an important stage of human development, when you share your knowledge and skills with younger people to pass on your legacy. Very little research has been conducted with Indigenous populations regarding their understanding of generativity and its role in well-being and mental health, but Indigenous Peoples refer to this as caring for the future or Seventh Generation. Indigenous Peoples engage in generative behaviors and act to preserve the history and culture of their community to ensure that youth can lead healthy lives, which is in direct contrast to Western understanding and reasons for being generative. Throughout our lives, we engage in healthy and unhealthy behaviors, which may or may not contribute to a healthy identity; this chapter discusses four cultural factors, or Indigenous cultural generative acts, used by Alaska Native Elders both to achieve sobriety and to fill the role of an Elder in their family and community. Also discussed is how these cultural factors can be used to guide the development of culture-specific mental health treatment approaches, and more broadly, prevention strategies for all ages. This intergenerational healing can result in pride and improved mental health for Indigenous Peoples of all ages. 

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