R. Gutenkunst, Ryan D. Hernandez, S. Williamson
et al.
Demographic models built from genetic data play important roles in illuminating prehistorical events and serving as null models in genome scans for selection. We introduce an inference method based on the joint frequency spectrum of genetic variants within and between populations. For candidate models we numerically compute the expected spectrum using a diffusion approximation to the one-locus, two-allele Wright-Fisher process, involving up to three simultaneous populations. Our approach is a composite likelihood scheme, since linkage between neutral loci alters the variance but not the expectation of the frequency spectrum. We thus use bootstraps incorporating linkage to estimate uncertainties for parameters and significance values for hypothesis tests. Our method can also incorporate selection on single sites, predicting the joint distribution of selected alleles among populations experiencing a bevy of evolutionary forces, including expansions, contractions, migrations, and admixture. We model human expansion out of Africa and the settlement of the New World, using 5 Mb of noncoding DNA resequenced in 68 individuals from 4 populations (YRI, CHB, CEU, and MXL) by the Environmental Genome Project. We infer divergence between West African and Eurasian populations 140 thousand years ago (95% confidence interval: 40–270 kya). This is earlier than other genetic studies, in part because we incorporate migration. We estimate the European (CEU) and East Asian (CHB) divergence time to be 23 kya (95% c.i.: 17–43 kya), long after archeological evidence places modern humans in Europe. Finally, we estimate divergence between East Asians (CHB) and Mexican-Americans (MXL) of 22 kya (95% c.i.: 16.3–26.9 kya), and our analysis yields no evidence for subsequent migration. Furthermore, combining our demographic model with a previously estimated distribution of selective effects among newly arising amino acid mutations accurately predicts the frequency spectrum of nonsynonymous variants across three continental populations (YRI, CHB, CEU).
Ancient migrations in Southeast Asia The past movements and peopling of Southeast Asia have been poorly represented in ancient DNA studies (see the Perspective by Bellwood). Lipson et al. generated sequences from people inhabiting Southeast Asia from about 1700 to 4100 years ago. Screening of more than a hundred individuals from five sites yielded ancient DNA from 18 individuals. Comparisons with present-day populations suggest two waves of mixing between resident populations. The first mix was between local hunter-gatherers and incoming farmers associated with the Neolithic spreading from South China. A second event resulted in an additional pulse of genetic material from China to Southeast Asia associated with a Bronze Age migration. McColl et al. sequenced 26 ancient genomes from Southeast Asia and Japan spanning from the late Neolithic to the Iron Age. They found that present-day populations are the result of mixing among four ancient populations, including multiple waves of genetic material from more northern East Asian populations. Science, this issue p. 92, p. 88; see also p. 31 Ancient genomes reveal four layers of human migration into Southeast Asia. The human occupation history of Southeast Asia (SEA) remains heavily debated. Current evidence suggests that SEA was occupied by Hòabìnhian hunter-gatherers until ~4000 years ago, when farming economies developed and expanded, restricting foraging groups to remote habitats. Some argue that agricultural development was indigenous; others favor the “two-layer” hypothesis that posits a southward expansion of farmers giving rise to present-day Southeast Asian genetic diversity. By sequencing 26 ancient human genomes (25 from SEA, 1 Japanese Jōmon), we show that neither interpretation fits the complexity of Southeast Asian history: Both Hòabìnhian hunter-gatherers and East Asian farmers contributed to current Southeast Asian diversity, with further migrations affecting island SEA and Vietnam. Our results help resolve one of the long-standing controversies in Southeast Asian prehistory.
Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood. Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago. We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of ‘Ancient North Siberians’ who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to ‘Ancient Palaeo-Siberians’ who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name ‘Neo-Siberians’, and from whom many contemporary Siberians are descended. Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas. Analyses of 34 ancient genomes from northeastern Siberia, dating to between 31,000 and 600 years ago, reveal at least three major migration events in the late Pleistocene population history of the region.
Abstract This study is a content analysis of K–12 U.S. history curriculum standards from 50 states regarding curricular re/presentation of Asian Americans. The guiding research questions are as follows: (1) What is the frequency of Asian American content covered in K–12 U.S. history standards from 50 states? (2) How do the standards depict Asian Americans in U.S. history? I analyzed U.S. history curriculum standards from all states using AsianCrit as a theoretical lens. The findings reveal that except for Japanese incarceration and anti-Asian immigration laws, Asian Americans are largely invisible in the state standards and, when included, they are primarily depicted as victims of nativist racism with a lack of civic agency as well as new immigrants with little contribution to nation-building. Being the first work to uncover curricular messages about Asian Americans across 50 states’ standards, this study presents a necessary empirical basis for disrupting curriculum violence.
Cyril Sajan, Varunsingh Saggu, Maitri Mahant
et al.
Cerebral venous sinus thrombosis (CVST) is a relatively uncommon but important cause of stroke-like disease, accounting for fewer than 1% of all strokes. CVST is more common in females and infants. CVST patients are most common in the third decade, with a female-to-male ratio of 5:1.5. The incidence of CVST has been found to be high in developing countries, particularly in South-East Asia. Headache is the most prevalent clinical sign of CVST, occurring in 88% to 93% of patients, followed by a seizure in 37% to 71%, focal neurological deficit in 20% to 54%, and isolated increased intracranial pressure in 23%.[1] A 34-year-old male came to the tertiary care hospital with complaints of headache, vomiting, and vertigo for 1 day. Headache is insidious, progressive, nonradiating, holocephalic, severe in intensity and associated with vertigo and dizziness, and giddiness, he also complained about nausea and vomiting (10–12 episodes/day) containing food and water. The patient had no family history but has been chronic tobacco chewer for 10 years. Past medical history revealed that he was admitted to the hospital before for the same complaints and he also had right lower vein deep-vein thrombosis 6 months back. His magnetic imaging resonance reports and protein S and C deficiency reports revealed that he was suffering from CVST. He was prescribed with anticoagulants and other supportive treatments that include antiemetic, analgesics, and multivitamins, which cause faster and better recovery of patients.
Este texto pretende construir nuevas miradas no eurocéntricas de la historia mundial al recuperar el legado de Ibn Khaldūn (1332-1406) e incorporarlo al escenario de la discusión poscolonial. Se plantea la necesidad de rescatar referentes no europeos y no occidentales para la conformación de una filosofía de la historia que reconozca la pluralidad de experiencias, epistemologías y cosmovisiones. Se proponen líneas de reflexión para una historia del mundo pensada desde la experiencia mediterránea occidental.
Diyendo Massilani, Laurits Skov, M. Hajdinjak
et al.
DNA analyses of an early East Asian Ancient, anatomically modern humans interbred with the archaic hominins Neanderthals and Denisovans. However, the extent of this interbreeding and how it affects modern populations is not well understood. Massilani et al. generated genome-wide data from a 34,000-year-old female individual from the Salkhit Valley in eastern Mongolia and conducted a detailed modeling of her ancestry with regard to other Pleistocene human genomes. They found evidence for Denisovan ancestry in ancient human genomes from at least 6000 years before the Salkhit individual lived and determined that the Denisovan contribution differed from that of another ancient Asian individual, as well as from the ancient Denisovan contribution to extant Australasians. This reference point helps us to understand the early history of our species in Eurasia, especially Eastern Eurasia, for which genomic evidence remains scarce. Science, this issue p. 579 A human skull from 34,000 years ago found in Mongolia elucidates the genetics of early East Asians and Denisovan admixture. We present analyses of the genome of a ~34,000-year-old hominin skull cap discovered in the Salkhit Valley in northeastern Mongolia. We show that this individual was a female member of a modern human population that, following the split between East and West Eurasians, experienced substantial gene flow from West Eurasians. Both she and a 40,000-year-old individual from Tianyuan outside Beijing carried genomic segments of Denisovan ancestry. These segments derive from the same Denisovan admixture event(s) that contributed to present-day mainland Asians but are distinct from the Denisovan DNA segments in present-day Papuans and Aboriginal Australians.
Stéphanie Sherpa, M. Blum, Thibaut Capblancq
et al.
Multiple introductions are key features for the establishment and persistence of introduced species. However, little is known about the contribution of genetic admixture to the invasive potential of populations. To address this issue, we studied the recent invasion of the Asian tiger mosquito (Aedes albopictus) in Europe. Combining genome‐wide single nucleotide polymorphisms and historical knowledge using an approximate Bayesian computation framework, we reconstruct the colonization routes and establish the demographic dynamics of invasion. The colonization of Europe involved at least three independent introductions in Albania, North Italy and Central Italy that subsequently acted as dispersal centres throughout Europe. We show that the topology of human transportation networks shaped demographic histories with North Italy and Central Italy being the main dispersal centres in Europe. Introduction modalities conditioned the levels of genetic diversity in invading populations, and genetically diverse and admixed populations promoted more secondary introductions and have spread farther than single‐source invasions. This genomic study provides further crucial insights into a general understanding of the role of genetic diversity promoted by modern trade in driving biological invasions.
Zoo-archaeological and genetic evidence suggest that pigs were domesticated independently in Central China and Eastern Anatolia along with the development of agricultural communities and civilizations. However, the genetic history of domestic pigs, especially in China, has not been fully explored. In this study, we generated 42 complete mitochondrial DNA sequences from ∼7500- to 2750-year-old individuals from the Yellow River basin. Our results show that the maternal genetic continuity of East Asian domestic pigs dates back to at least the Early to Middle Neolithic. In contrast, the Near Eastern ancestry in European domestic pigs saw a near-complete genomic replacement by the European wild boar. The majority of East Asian domestic pigs share close haplotypes, and the most recent common ancestor of most branches dates back to less than 20,000 years before present, inferred using new substitution rates of whole mitogenomes or combined protein-coding regions. Two major population expansion events of East Asian domestic pigs coincided with changes in climate, widespread adoption of introduced crops, and the development of agrarian societies. These findings add to our understanding of the maternal genetic composition and help to complete the picture of domestic pig evolutionary history in East Asia.
Ana Bertha Cuevas Tello, Nora Elena Preciado Caballero
Ante el cambio climático, se sostiene que la disposición a cooperar de los Estados se fundamenta en alguna de las caras que, en el ámbito de lo climático, nos ofrece la geopolítica: las fortalezas o las debilidades (entendidas como vulnerabilidad) de las condiciones geográficas, la ubicación y el territorio, es decir, los factores físicos, geográficos, económicos y demográficos de cada Estado influyen en la toma de decisiones de su política exterior climática, la cual los induce a cooperar o a abstenerse. En este trabajo se abordará, grosso modo, la participación de las principales economías de Asia Pacífico en la institucionalización del cambio climático en la agenda internacional; la importancia de las economías de Asia Pacífico frente al Acuerdo de París, y las fortalezas y las debilidades geopolíticas que explican el comportamiento cooperador o no de la región en la lucha contra el cambio climático.
The paper is devoted to the perception of Kazan and Kazan province as the Russian East by French travelers. Astolphe de Custine and André Durand traveled to Russia in 1839. Custine, following the results of his visit to Russia, wrote the book “Russia in 1839” (La Russie en 1839). Duran captured the images of Russia in lithographs. The relevance of the research is due to the widespread opinion of Custine’s work as the beginning of the collective dislike of the West for Russia. The scientific importance is determined by the source study of the correlation of texts and artistic images on one topic. The study was performed to find out the impressions that Custine could get from Kazan as the oriental locus of the Russian Empire. As a means of verifying the alternative history hypothesis, nine Durand’s lithographs of Kazan were used. The results of the study include: the evolution of Custine’s ideas about Russia from the embodiment of the East to the phenomenon on the border of Asia and Europe; Custine’s emotional and intellectual discomfort as the cause of the hypercriticism of his book; Custine’s refusal to visit Kazan as a missed opportunity to see the eastern nature of Russia; Durand fixing the Islamic, Tatar realities in Kazan and Kazan province. The results obtained are important for the formulation and solution of the following problems: source study of synchronous and monocultural representations of textual and graphic visualization; research on Custine’s book “Russia in 1839” in connection with Durand’s lithographs; study of Kazan local history and everyday life.
History of scholarship and learning. The humanities
What are the characteristics of contemporary Japanese nationalism? And is there a “surge of nationalism in Japan,” as so often claimed (Kitaoka 2001; Sasaki 2001; Hasegawa and Togo 2008; NYT 2013), or even a “drift to the right” in the country (Kato 2014; Nakano 2015)? Distinguishing between elite maneuverings and popular attitudes, in this article I first identify what I consider to be the major topics of current nationalist discourse, and then introduce the chief proponents of strengthening of nationalist attitudes in society. In the final section, I discuss some recent attempts to instill nationalist attitudes in young people through middle-school education, especially the teaching of history and civics, but also through moral education. I conclude that in light of a political establishment tarnished by never-ending scandals, attempts to force moral education into the curriculum as a way of fostering nationalist and patriotic attitudes among young people is a particularly duplicitous undertaking, discrediting the very notions so highly praised by its advocates.