American Journal of Human Biology最新文献

{"title":"Developmental Influences on Racial Inequities in Cardiovascular Health: The Push–Pull Forces That Uncouple Cardiovascular Disease From Birth Weight","authors":"Christopher W. Kuzawa,&nbsp;Elizabeth Sweet","doi":"10.1002/ajhb.70125","DOIUrl":"https://doi.org/10.1002/ajhb.70125","url":null,"abstract":"<div>\u0000 \u0000 <p>In 2009 we published an article in the <i>American Journal of Human Biology</i> arguing for a developmental contribution to US racial inequities in cardiovascular disease (CVD), inspired by emerging evidence that stress during pregnancy reduces birth weight (BW) while also elevating offspring CVD risk. The 15 years since our piece was published provide an opportunity to update the status of the hypothesis. Although relevant studies are sparse, work to date has revealed an apparent paradox: although Black Americans have lower BWs and higher CVD rates, and even though lower BW elevates future CVD risk, studies generally report stronger inverse BW–CVD relationships in white compared to Black samples. Drawing on current understandings of intergenerational pathways, we propose an updated model that could help explain the weakening of BW–CVD relationships in Black Americans: Structural racism not only elevates CVD risk through pathways that reduce BW, as we originally emphasized, but also increases the likelihood of maternal weight gain and elevated glucose, which elevate offspring CVD risk but <i>increase</i> BW. We review newer evidence that these offsetting, “push–pull” effects on BW operate across the full BW spectrum. As a result, when BW is used as a marker, a dimension of CVD risk is rendered invisible, with the degree of invisibility proportionate to the strength of these opposing pathways. BW will thus be particularly uncoupled from CVD risk in minoritized US populations, who often face psychosocial stress but are also more likely to be exposed to environments that lead to weight gain and metabolic dysregulation.</p>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144894265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Son Preference and Third-Birth Interval Comparative Analysis of Polygynous Versus Monogamous Families in Pakistan","authors":"Juan Wu,&nbsp;Athar Ali Shah","doi":"10.1002/ajhb.70127","DOIUrl":"https://doi.org/10.1002/ajhb.70127","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>Son preference remains a deeply rooted sociocultural phenomenon in Pakistan and plays a critical role in shaping fertility behavior. The study investigates the influence of son preference on fertility behavior, with a specific focus on birth intervals and the sex composition of existing children, within the context of marital structure (monogamous vs. polygynous unions) in Pakistan.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>Using nationally representative data from the Pakistan Demographic and Health Survey (2012–2013 and 2017–2018), data are analyzed using Cox proportional hazards regression to assess the timing of subsequent births at parity three and linear regression to measure son preference. The sample size included 100 733 women of reproductive age (15–49 years), of whom 96 975 were in monogamous unions and 3758 were in polygynous unions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The results demonstrate a persistent and significant son preference in fertility decisions. Women with fewer or no sons are more likely to proceed to another birth, as evidenced by shorter birth intervals. A key finding is that polygynous marriages are associated with both higher son preference and shorter birth intervals compared to monogamous unions. While rural polygynous women exhibit stronger son preference, urban polygynous women tend to have quicker transitions to the next birth. In contrast, monogamous women generally report longer birth intervals and lower levels of son preference, regardless of residence.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The study finds that polygynous marriages are associated with stronger son preference compared to their monogamous counterparts. While rural polygynous women exhibit a stronger son preference than urban polygynous women, the latter have shorter birth intervals.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144894266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of Possible Allometric Interactions in Human Hand Digit Lengths on Sexual Dimorphism of Digit Ratios","authors":"Görel Aksoy,&nbsp;Barış Özener","doi":"10.1002/ajhb.70126","DOIUrl":"https://doi.org/10.1002/ajhb.70126","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>This study was conducted to determine whether possible allometries in hand digit lengths have an effect on the observed sexual dimorphism in digit ratios.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The lengths of four digits from the second to the fifth digits on the right and left hands of 500 adult participants (250 males, 250 females) were measured and six different ratios were calculated. ANCOVA and regression analyses were used to examine the allometry effect.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The findings revealed that the sexual dimorphism that emerged in the right and left 2D:4D ratios was independent of the allometry effect. On the other hand, it was observed that the allometry effect emerged in the three digit ratios (right and left 2D:5D, left 3D:5D).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These results reveal that the allometry effect is not observed on the ratios calculated from the digits (2D and 4D) that are claimed to have formed under the influence of prenatal steroids, but it can be observed on the other digits.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144897498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing Threats to Research and Global Engagement in Human Biology","authors":"William R. Leonard,&nbsp;Noël Cameron","doi":"10.1002/ajhb.70116","DOIUrl":"https://doi.org/10.1002/ajhb.70116","url":null,"abstract":"<p>Human Biology is a young science asking the oldest of questions: Who are we? From what did we evolve? How did we deal with threats to our existence? What physiological and morphological adaptations did we develop that allowed our survival and fitness through evolutionary time? In the 21st century, after over three million years of human evolutionary change, what biological characteristics allow us to deal with the existential onslaught that is now affecting our daily lives?</p><p>These questions are not just interesting in their own right, but their answers are fundamental to the future of our species and are critically important to addressing long-standing inequities in health outcomes among human populations around the world. Arguably, the most important characteristic of <i>Homo sapiens</i> is our ability to acquire and use knowledge to understand the world around us. In that acquisition, it is the identification of the problem, the sharing of the search, and the answers that allows our onward existence. Threats to the research that targets those specific questions are a threat to humanity.</p><p>Since the dawn of the enlightenment in the 17th century, the speed with which we have been able to acquire and use knowledge has gathered pace, requiring ever more sophisticated methods of the sharing and transfer of knowledge through education so that the next generation profits from our endeavors and continues the journey.</p><p>We believe that threats exist to the educational and research methods that are the basis of our academic freedom to explore existential questions. These threats to science and promotion of conspiracy theories must be identified and rejected.</p><p>The consequences of the actions by the Trump administration are being felt across academia, research institutions, international development agencies, and in the broader global scientific community. As international organizations of Human Biologists, we believe that our collective voice must be heard at this time of crisis to argue for and create a constructive future pathway and not one that destroys the very advantages that have made our species so successful. We believe that government policies that emphasize deregulation, budget cuts, and restrictions on research and global engagement in the health and life sciences are ultimately destructive and must be objected to at every juncture.</p><p>We join the voices of our colleagues internationally and through the American National Academies of Sciences, Engineering, and Medicine when we agree that while we hold diverse political beliefs, we are united as researchers in wanting to protect independent scientific inquiry for the future of our species.</p><p>Statement of Editorial Independence: The views expressed here are solely those of the authors and do not necessarily represent those of the publisher.</p>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.70116","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contributions of Roy J. Shephard to the Study of Circumpolar Human Biology and Health","authors":"William R. Leonard,&nbsp;Peter T. Katzmarzyk","doi":"10.1002/ajhb.70123","DOIUrl":"https://doi.org/10.1002/ajhb.70123","url":null,"abstract":"<p>More than any other scholar in our field, Professor Roy J. Shephard's research has shaped and transformed our understanding of the biology and health of circumpolar populations. His long-term research among the Inuit of Igloolik, Canada has provided the field of human biology with foundational insights into how human populations adapt to arctic climates, and how the transition to a market-oriented lifestyle erodes fitness and metabolic health. Shephard was the prime architect of early research done in the Canadian Arctic as part of the Human Adaptability Program (HAP) of the International Biological Programme (IBP) in the 1960s and early 1970s. After the original IBP studies, Shephard and collaborator Andris Rode continued their research in Igloolik through the early 1990s. This long-term research provided some of the first clear evidence on how the process of acculturation and lifestyle change erodes physical development and metabolic health among Indigenous populations of the north. This paper provides an overview of the major findings and insights from Roy Shephard and colleagues' research in Igloolik and highlights how these contributions are shaping ongoing research on the biology and health of circumpolar populations.</p>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.70123","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144869896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Relationship Between Body Mass Index, Socioeconomic and Geographic Factors With Somatic Maturation in Mexican Children","authors":"Luis Alberto Flores,&nbsp;Liliana Aracely Enríquez-del Castillo,&nbsp;Sudip Datta Banik,&nbsp;Damian Laborde-Daisson,&nbsp;Natanael Cervantes-Hernández,&nbsp;Estefanía Quintana-Mendias,&nbsp;Cinthia Verónica Villegas-Balderrama,&nbsp;Judith Margarita Rodríguez-Villalobos","doi":"10.1002/ajhb.70121","DOIUrl":"https://doi.org/10.1002/ajhb.70121","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>To analyze the influence of sociodemographic factors and BMI-based nutritional status on the somatic maturity of Mexican children.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>BMI-based nutritional status and maturity offset by the Moore-II method were estimated. Information on age, sex, weight, height of 2- to 18-year-old children and adolescents, household socioeconomic status, and geographic region were obtained from the 2012 and 2018 databases of the National Health and Nutrition Survey (ENSANUT), National Institute of Public Health (INSP), and the National Institute of Statistics and Geography (INEGI) in Mexico. Saturated log-linear and logistic regression models were used to evaluate the associations among the variables. The association between the prevalence of excess weight (BMI-based overweight and obesity) and age, transforming the logistic model to a linear model using the logit function, was estimated.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The prevalence of overweight and obesity showed a cubic correlation with age and maturity offset in both sexes. In boys, the highest prevalence was observed at ages 12–14 years, which coincides with the peak height velocity. In girls, the highest prevalence occurred at ages 14–15 years, with this trend being stronger than in boys; additionally, overweight and obesity prevalence peaks at −2 and −1 years from APHV in boys, and between 0 and 2 years from APHV in girls. Children from rural areas, lower socioeconomic levels, and those from the southern region had a higher probability of late somatic maturity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Socioeconomic and geographic factors play important roles in shaping nutritional status and somatic maturation patterns in Mexican children. Health and nutrition intervention programs and strategies for children and adolescents, based on these factors, are recommended.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144881280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biological Benchmarks for Adult Bone Mass Proportions in Young Females: A Prospective Longitudinal Analysis","authors":"Jodi N. Dowthwaite,&nbsp;Stephanie A. Kliethermes,&nbsp;Tamara A. Scerpella","doi":"10.1002/ajhb.70118","DOIUrl":"https://doi.org/10.1002/ajhb.70118","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>In growing humans, densitometric scans of whole-body bone mass “less head” are recommended to circumvent the excessive contribution of youths' proportionally larger heads but potentially inflate inter-scan variation and least significant change due to measurement error. We aimed to determine biological benchmarks for achievement of adult head-body proportions in a sample of US females.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Annual whole-body dual energy x-ray absorptiometry (DXA) scans tracked growth, maturation, and bone mass accrual in a prospective longitudinal cohort of girls for up to 19 years (baseline age 7–15 years). We used cubic smoothing spline mixed effects models to generate chronological and gynecological age-based curves for head versus whole-body bone mass proportions (ratios). Females with ≥ 3 annual scans were included (<i>n</i> = 148, age 7–30 years).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Models yielded trajectories extending beyond observed age at peak bone mass for our sample. From age 18 years, “adult” mean of means for head vs. whole-body bone mass proportions was 0.204 (<i>n</i> = 66: 95% confidence interval = 0.198–0.210). Individual proportions stabilized to “adult” mean levels circum-menarche (<i>n</i> = 124: mean = 0.198; 95% confidence interval = 0.194–0.202). The minimum age for 95% confidence intervals overlapping with adult values was 12 years, circum-peak height velocity (<i>n</i> = 120: mean = 0.211; 95% confidence interval = 0.207–0.216).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>In US girls with diverse activity exposures, head vs. whole-body bone mass proportions are “adult” from menarche onward; an “adult” age threshold of 12 years, or age at peak height velocity, may be used in the absence of extreme maturational delay to evaluate whole-body bone mass including the head.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.70118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Species-Specific Helminth Effects, Ecoimmunology, and Indigenous Health: Commentary on Cepon-Robins et al. (2025)","authors":"Nathkapach Kaewpitoon Rattanapitoon,&nbsp;Kornmaneethana Punnasirimangmee,&nbsp;Pattharasedthi Pholyiam,&nbsp;Schawanya Kaewpitoon Rattanapitoon","doi":"10.1002/ajhb.70117","DOIUrl":"https://doi.org/10.1002/ajhb.70117","url":null,"abstract":"","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association Between Motor Competence, Executive Functions, and Self-Regulation: A Complex Systems Approach","authors":"Morgana Alves Correia da Silva,&nbsp;Clarice Maria de Lucena Martins,&nbsp;Michelly Alencar Alencar,&nbsp;Paulo Renato Alves Firmino,&nbsp;Paulo Felipe Ribeiro Bandeira","doi":"10.1002/ajhb.70110","DOIUrl":"https://doi.org/10.1002/ajhb.70110","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Background&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;There are several associated factors that have an impact on a child's development, including the cognitive and motor domains. Motor competence is intrinsically linked to executive functioning, even though the causal links between the development of motor skills and the development of cognitive skills are not always obvious. Even in early childhood, with advances in cognitive processes in the child's development, processes emerge that make the child capable of regulating their own behavior.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Objectives&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;These variables are important for child development; however, there are no previous studies that examine the associations of motor competence, executive functions, and self-regulation together. There is also no study that takes a holistic view to better understand the interrelationships of these variables. This study aimed to investigate the association between motor competence, executive functions, and self-regulation in childhood and identify the variables with the highest network influence values.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;The research adopted a cross-sectional design; it is a descriptive and associative study. Two hundred and eighty-three children aged 3–6 years of both sexes, from two of the most populous cities in the interior of northeastern Brazil participated. The instruments used were the TGMD-3 for motor competence, the Early Years Toolbox battery for executive functions, and HTKS-R for self-regulation. The data was analyzed using network analysis.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Results&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;It was observed that motor competence and executive functions were positively related, and self-regulation had an indirect association with motor competence. These findings corroborate previous studies on the relationship between motor competence and executive functions and highlight the importance of self-regulation in this association. The network showed clusters between motor competence skills, executive functions, and self-regulation, which are part of the same construct. The skills of running, receiving, kicking, and inhibitory control had the highest centrality rates, highlighting their importance for the interconnection of variables. The highest values of expected influence were from running, inhibitory control, and kicking, modifications of which can result in significant changes in the overall behavior of the network.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Conclusions&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;These findings reinforce the integrated nature of motor, cognitive, and self-regulat","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144815032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Fertility Effects of the C677T Mutation in the Methylenetetrahydrofolate Reductase Gene: A Cross-Site Systematic Review and Meta-Analysis","authors":"Caroline A. MacLean,&nbsp;Miguel Dimanlig,&nbsp;David Godfrey,&nbsp;Lorena Madrigal","doi":"10.1002/ajhb.70119","DOIUrl":"https://doi.org/10.1002/ajhb.70119","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>In this research, we seek to understand the evolutionary forces which have resulted in the distribution of the MTHFR C677T single nucleotide polymorphism, which is associated with fertility-related, cardiovascular, cancerous, and neurological morbidities. Due to the negative effects of the gene, it is likely frequent due to genetic drift or natural selection.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using secondary data gathered by systematic review, we test proposals stating that under conditions of ample folate, individuals who are heterozygous (CT) and homozygous (TT) for the MTHFR C677T polymorphism would suffer from fewer or no deleterious pregnancy or birth outcomes. Using descriptive and bivariate statistics, we determined if significant differences exist between pregnancy or birth outcomes based on genotype. We then modeled the effects of genotype, folate, cobalamin, and homocysteine (and their interactions) on the frequency of the pregnancy outcomes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Even with ample and high serum folate, CT and TT women sampled had worse pregnancy outcomes. Folate (sometimes interacting with insolation) mediates pregnancy outcomes in a genotype-dependent fashion. For this reason, we caution against the use of a “one size fits all” approach to clinical treatment for CT and TT individuals.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We conclude that natural selection is the primary force of evolution acting on this mutation despite its numerous negative effects. We reject the hypothesis that in conditions of ample folate supply, CT or TT pregnant people might have a fitness advantage. Genotype was a strong predictor of birth outcomes, indicating that for this polymorphism, there is a strong folate-genotypic and genotype-insolation interaction.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"37 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}