Human Biology最新文献

Thirty-eight skull samples of ancient children were analyzed that were excavated from the Zaghunluq cemetery, which dates between 2600 and 1900 cal yr BP. The orbit features of children during age changes and growth spurt periods were explored by comparing the orbital height, orbital breadth, orbital area, orbital index, and other measurements among different age groups: 2 years, 3-5 years, 6-8 years, 9-11 years, and 12-15 years. The analysis showed significant differences in orbital breadth across the five age groups, while differences in orbital height, orbital area, and orbital index were not significant. The growth spurt period of orbital breadth I was during 3-5 years of age, and the growth spurt period of orbital breadth II occurred during 6-8 years. Notably, the orbital height of a 2-year-old child has reached 92.7% of adult size. This may elucidate changes in the orbits of children due to age in ancient Xinjiang, China.

Social norms regarding who marries whom have changed dramatically in the United States across the 20th century. These changes may influence the level of genetic similarity between spouses. This study investigates whether genetic similarity in height between husband and wife was influenced by a historical transition in spouse selection criteria. The great transition from the companionate marriage to the individualized marriage occurred in the 1960s. In the companionate marriage, husband and wife chose each other as companions, and the emphasis was on playing marital roles well: husbands being good breadwinners and wives being good homemakers. In the individualized marriage, the emphasis switched to individual feelings, and as a result, when choosing their partners people tended to pay less attention to height, suggesting a smaller genetic correlation for height between spouses. Using data from the Health and Retirement Study, we found that the genetic correlation for height declined substantially in the individualized marriage. We conducted a number of analyses to test for the confounding effects of cohort and age and to address population stratification, selection issues, and genetic relatedness between spouses. Evidence suggests that the effect of this transition is robust.

The Austronesian Diaspora is a 5,000-year account of how a small group of Taiwanese farmers expanded to occupy territories reaching halfway around the world. Reconstructing their detailed history has spawned many academic contests across many disciplines. An outline orthodox version has eventually emerged but still leaves many unanswered questions. The remarkable power of whole-genome technology has now been applied to people across the entire region. This review gives an account of this era of genetic investigation and discusses its many achievements, including revelation in detail of many unexpected patterns of population movement and the significance of this information for medical genetics.

Recent studies have produced a variety of advances in the investigation of genetic similarities and differences among human populations. In this reprinted article, originally published in Human Biology in 2011 (vol. 83, no. 6, pp. 659-684), I pose a series of questions about human population-genetic similarities and differences, and I then answer these questions by numerical computation with a single shared population-genetic data set. The collection of answers obtained provides an introductory perspective for understanding key results on the features of worldwide human genetic variation. A new foreword discusses the original article in light of the research that has followed.

Isolation-by-distance models are part of the institutional creed of antiracialism used to critique claims of biological race concepts (BRCs). Proponents of antiracialism appeal to isolation-by-distance models to describe patterns of human genetic differences among and between groups as a function of distance. Isolation by distance has been referred to as the pattern that human genetic variation fits, distributing the differences we see as race throughout geographic space as a series of Gaussian gradients. Contemporary scientific critiques of BRCs fuse social constructionist race concepts with a description of the distribution of proportions of human genetic variation in geographic space as a function of distance. These two points are often followed by statements noting that there is only one human race. How these two concepts connect to each other, and whether or not they connect at all, is unclear in both academic and nonacademic spaces. Consequently, scientists and the public lack an understanding of human population structure and its relationships to varying systems of human interactions. This article reviews isolation-by-distance models in population genetics and the use of these models in the modern problem of human difference. The article presents a historical and conceptual review of isolation-by-distance models and contemporary scientific critiques of BRCs, followed by examples of the use of isolation-by-distance models in studies of human genetic variation. To address the shortcomings in the scientific critique of race, the author proposes combining Du Boisian demography with Darwinian evolutionary biology. From a Du Boisian demographic perspective, race is a product of racism, or race/ism, and is a heredity and inheritance system based on rules of partus sequitur ventrem and hypodescent. Race marks individuals and groups them to reproduce unequal relationships into which Europeans co-opted them. This synthesis propounds a new racial formation theory to understand the more general consequences of racism on genes and health outcomes.

Geneticists have argued that the linear decay in within-population genetic diversity with increasing geographic distance from East Africa is best explained by a phylogenetic process of repeated founder effects, growth, and isolation. However, this serial founder effect (SFE) process has not yet been adequately vetted against other evolutionary processes that may also affect geospatial patterns of diversity. Additionally, studies of the SFE process have been largely based on a limited 52-population sample. In this modestly updated article, originally published in Human Biology in 2016 (vol. 88, no. 3, pp. 219-231), we assess the effects of founder effect, admixture, and localized gene flow processes on patterns of global and regional diversity using a published data set of 645 autosomal microsatellite genotypes from 5,415 individuals in 248 widespread populations. We used a formal tree-fitting approach to explore the role of founder effects. The approach involved fitting global and regional population trees to extant patterns of gene diversity and then systematically examining the deviations in fit. We also informally tested the SFE process using linear models of gene diversity versus waypoint geographic distances from Africa. We tested the role of localized gene flow using partial Mantel correlograms of gene diversity versus geographic distance controlling for the confounding effects of treelike genetic structure. We corroborate previous findings that global patterns of diversity, both within and between populations, are the product of an out-of-Africa SFE process. Within regions, however, diversity within populations is uncorrelated with geographic distance from Africa. Here, patterns of diversity have been largely shaped by recent interregional admixture and secondary range expansions. Our detailed analyses of the pattern of diversity within and between populations reveal that the signatures of different evolutionary processes dominate at different geographic scales. These findings have important implications for recent publications on the biology of race. Our new foreword situates these findings in a long line of anthropological research that categorically rejects racial interpretations of analyses of human diversity.