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Noncommunicable diseases (NCDs) are on the rise worldwide. Obesity, cardiovascular disease, and type 2 diabetes are among a long list of lifestyle diseases that were rare throughout human history but are now common. The evolutionary mismatch hypothesis posits that humans evolved in environments that radically differ from those we currently experience; consequently, traits that were once advantageous may now be mismatched and disease causing. At the genetic level, this hypothesis predicts that loci with a history of selection will exhibit genotype by environment (GxE) interactions, with different health effects in ancestral versus modern environments. To identify such loci, we advocate for combining genomic tools in partnership with subsistence-level groups experiencing rapid lifestyle change. In these populations, comparisons of individuals falling on opposite extremes of the matched to mismatched spectrum are uniquely possible. More broadly, the work we propose will inform our understanding of environmental and genetic risk factors for NCDs across diverse ancestries and cultures.

Research among non-industrial societies suggests that body kinematics adopted during running vary between groups according to the cultural importance of running. Among groups in which running is common and an important part of cultural identity, runners tend to adopt what exercise scientists and coaches consider to be good technique for avoiding injury and maximising performance. In contrast, among groups in which running is not particularly culturally important, people tend to adopt suboptimal technique. This paper begins by describing key elements of good running technique, including landing with a forefoot or midfoot strike pattern and leg oriented roughly vertically. Next, we review evidence from non-industrial societies that cultural attitudes about running associate with variation in running techniques. Then, we present new data from Tsimane forager-horticulturalists in Bolivia. Our findings suggest that running is neither a common activity among the Tsimane nor is it considered an important part of cultural identity. We also demonstrate that when Tsimane do run, they tend to use suboptimal technique, specifically landing with a rearfoot strike pattern and leg protracted ahead of the knee (called overstriding). Finally, we discuss processes by which culture might influence variation in running techniques among non-industrial societies, including self-optimisation and social learning.

Equations for predicting body mass from stature and bi‐iliac (maximum pelvic) breadth have been developed, but have had variable success when applied to living or recently deceased individuals, calling into question their general applicability. Here we test these equations on a large, ethnically diverse sample. Skeletal and anthropometric data for 507 recently deceased Indigenous, Hispanic, and non‐Hispanic White adults were obtained from the New Mexico Decedent Image Database. The body mass of individuals with a "normal" body mass index (BMI = 18.5–24.9) is very accurately predicted, with an average directional bias of about 1% and an average random error of less than 8%. Underweight individuals (BMI < 18.5) are overpredicted, while overweight (BMI = 25–29.9) and especially obese (BMI≥30) individuals are underpredicted. Within BMI categories, there is a strong and isometric relationship between predicted and true body mass. Individual body mass prediction errors using the stature/bi‐iliac method are mainly dependent on variation in BMI. Because earlier humans were more likely to fall within or close to the normal BMI range, the equations should be applicable, on an individual basis, in archeological and paleontological contexts. Because of the prevalence of obesity in many modern populations, these equations are not applicable in a general forensic context. We derive new equations from nonobese individuals in our sample (n = 338), which produce reasonable average prediction errors. If obese individuals can be identified using other skeletal parameters, these equations may be useful in estimating body mass in nonobese forensic cases. [ABSTRACT FROM AUTHOR]

The convergent evolution of the human pygmy phenotype in tropical rainforests is widely assumed to reflect adaptation in response to the distinct ecological challenges of this habitat (e.g. high levels of heat and humidity, high pathogen load, low food availability, and dense forest structure), yet few precise adaptive benefits of this phenotype have been proposed. Here, we describe and test a biomechanical model of how the rainforest environment can alter gait kinematics such that short stature is advantageous in dense habitats. We hypothesized that environmental constraints on step length in rainforests alter walking mechanics such that taller individuals are expected to walk more slowly due to their inability to achieve preferred step lengths in the rainforest. We tested predictions from this model with experimental field data from two short-statured populations that regularly forage in the rainforest: the Batek of Peninsular Malaysia and the Tsimane of the Bolivian Amazon. In accordance with model expectations, we found stature-dependent constraints on step length in the rainforest and concomitant reductions in walking speed that are expected to compromise foraging efficiency. These results provide the first evidence that the human pygmy phenotype is beneficial in terms of locomotor performance and highlight the value of applying laboratory-derived biomechanical models to field settings for testing evolutionary hypotheses.

The deposition of cellulose is a defining aspect of plant growth and development, but regulation of this process is poorly understood. Here, we demonstrate that the protein kinase BRASSINOSTEROID INSENSITIVE2 (BIN2), a key negative regulator of brassinosteroid (BR) signaling, can phosphorylate Arabidopsis cellulose synthase A1 (CESA1), a subunit of the primary cell wall cellulose synthase complex, and thereby negatively regulate cellulose biosynthesis. Accordingly, point mutations of the BIN2-mediated CESA1 phosphorylation site abolished BIN2-dependent regulation of cellulose synthase activity. Hence, we have uncovered a mechanism for how BR signaling can modulate cellulose synthesis in plants.

Objectives: Comparisons between Indigenous peoples over time and within a particular geographic region can shed light on the impact of environmental transitions on the skeleton, including relative bone strength, sexual dimorphism, and age‐related changes. Here we compare long bone structural properties of the inhabitants of the late prehistoric‐early historic Pecos Pueblo with those of present‐day Indigenous individuals from New Mexico. Materials and Methods: Femora and tibiae of 126 adults from Pecos Pueblo and 226 present‐day adults were included in the study. Cross‐sectional diaphyseal properties—areas and second moments of area—were obtained from past studies of the Pecos Pueblo skeletal sample, and from computed tomography scans of recently deceased individuals in the present‐day sample. Results: Femora and tibiae from Pecos individuals are stronger relative to body size than those of present‐day Indigenous individuals. Present‐day individuals are taller but not wider, and this body shape difference affects cross‐sectional shape, more strongly proximally. The tibia shows anteroposterior strengthening among Pecos individuals, especially among males. Sexual dimorphism in midshaft bone shape is stronger within the Pecos Pueblo sample. With aging, Pecos individuals show more medullary expansion but also more subperiosteal expansion than present‐day individuals, maintaining bone strength despite cortical thinning. Discussion: Higher activity levels, carried out over rough terrain and throughout adult life, likely explain the relatively stronger lower limb bones of the Pecos individuals, as well as their greater subperiosteal expansion with aging. Greater sexual dimorphism in bone structure among Pecos individuals potentially reflects greater gender‐based differences in behavioral patterns. [ABSTRACT FROM AUTHOR]

Background Increasing fruit and vegetable (FV) consumption is associated with reduced cardiovascular disease risk in observational studies but with little evidence from randomised controlled trials (RCTs). The impact of concurrent pharmacological therapy is unknown. Objective To pool data from six RCTs to examine the effect of increasing FV intake on blood pressure (BP) and lipid profile, also exploring whether effects differed by medication use. Design Across trials, dietary intake was assessed by diet diaries or histories, lipids by routine biochemical methods and BP by automated monitors. Linear regression provided an estimate of the change in lipid profile or BP associated with a one portion increase in self-reported daily FV intake, with interaction terms fitted for medication use. Results The pooled sample included a total of 554 participants (308 males and 246 females). Meta-analysis of regression coefficients revealed no significant change in either systolic or diastolic BP per portion FV increase, although there was significant heterogeneity across trials for systolic BP (I 2 = 73%). Neither adjusting for change in body mass index, nor analysis according to use of anti-hypertensive medication altered the relationship. There was no significant change in lipid profile per portion FV increase, although there was a significant reduction in total cholesterol among those not on lipid-lowering therapy (P  < 0.05 after Bonferroni correction). Conclusion Pooled analysis of six individual FV trials showed no impact of increasing intake on BP or lipids, but there was a total cholesterol-lowering effect in those not on lipid-lowering therapy. [ABSTRACT FROM AUTHOR]

Objectives: To document frontal sinus volume (FSV) in a sample of sub‐Saharan Africans with a view to evaluating claims that such populations exhibit comparatively small sinuses. This study also addresses questions related to sexual dimorphism, incidence of sinus aplasia, and the possibility that FSV continues to increase through adulthood. Materials and methods: FSV was measured from CT scans of adult crania from the Dart Collection. Sex and age were known for each individual. Linear cranial dimensions were used to compute a geometric mean from which a scaled FSV was computed for each cranium. Results: FSV does not differ significantly between sexes, but females exhibit a higher incidence of aplasia. There is considerable variation in FSV in this sample, with the average ranking among the higher means reported for other population samples. The incidence of FS aplasia falls within the range of values recorded for other population samples. Although our study is cross‐sectional rather than longitudinal, there is strong evidence that FSV continues to increase with age throughout adulthood. Discussion: The FSV mean of our sample contradicts the notion that sub‐Saharan Africans possess small sinuses. In a global context, geography (climate and altitude) does not appear to be related to FSV. The absence of sexual dimorphism in our sample is unexpected, as significant dimorphism has been reported for most other population samples. Our results support other indications that the frontal sinus continues to expand throughout adulthood, especially in females, and that it is likely due to bone resorption. Research Highlights: Frontal sinus volume in black South Africans is comparable to that in samples from other geographic regions.Frontal sinus volume is not sexually dimorphic among South Africans.The frontal sinus continues to expand throughout adulthood in this sample. [ABSTRACT FROM AUTHOR]