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1.
Evol Med Public Health ; 11(1): 397-414, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37954982

RESUMO

Background and objectives: Epigenetic estimators based on DNA methylation levels have emerged as promising biomarkers of human aging. These estimators exhibit natural variations across human groups, but data about indigenous populations remain underrepresented in research. This study aims to investigate differences in epigenetic estimators between two distinct human populations, both residing in the Gran Chaco region of Argentina, the Native-American Wichí, and admixed Criollos who are descendants of intermarriages between Native Americans and the first European colonizers, using a population genetic approach. Methodology: We analyzed 24 Wichí (mean age: 39.2 ± 12.9 yo) and 24 Criollos (mean age: 41.1 ± 14.0 yo) for DNA methylation levels using the Infinium MethylationEPIC (Illumina) to calculate 16 epigenetic estimators. Additionally, we examined genome-wide genetic variation using the HumanOmniExpress BeadChip (Illumina) to gain insights into the genetic history of these populations. Results: Our results indicate that Native-American Wichí are epigenetically older compared to Criollos according to five epigenetic estimators. Analyses within the Criollos population reveal that global ancestry does not influence the differences observed, while local (chromosomal) ancestry shows positive associations between specific SNPs located in genomic regions over-represented by Native-American ancestry and measures of epigenetic age acceleration (AgeAccelHannum). Furthermore, we demonstrate that differences in population ecologies also contribute to observed epigenetic differences. Conclusions and implications: Overall, our study suggests that while the genomic history may partially account for the observed epigenetic differences, non-genetic factors, such as lifestyle and ecological factors, play a substantial role in the variability of epigenetic estimators, thereby contributing to variations in human epigenetic aging.

2.
Int J Mol Sci ; 23(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35743173

RESUMO

The high number of matching haplotypes of the most common mitochondrial (mt)DNA lineages are considered to be the greatest limitation for forensic applications. This study investigates the potential to solve this constraint by massively parallel sequencing a large number of mitogenomes that share the most common West Eurasian mtDNA control region (CR) haplotype motif (263G 315.1C 16519C). We augmented a pilot study on 29 to a total of 216 Italian mitogenomes that represents the largest set of the most common CR haplotype compiled from a single country. The extended population sample confirmed and extended the huge coding region diversity behind the most common CR motif. Complete mitogenome sequencing allowed for the detection of 163 distinct haplotypes, raising the power of discrimination from 0 (CR) to 99.6% (mitogenome). The mtDNAs were clustered into 61 named clades of haplogroup H and did not reveal phylogeographic trends within Italy. Rapid individualization approaches for investigative purposes are limited to the most frequent H clades of the dataset, viz. H1, H3, and H7.


Assuntos
DNA Mitocondrial , Genoma Mitocondrial , DNA Mitocondrial/genética , Genética Populacional , Haplótipos/genética , Núcleo Familiar , Projetos Piloto , Análise de Sequência de DNA
3.
Biology (Basel) ; 10(12)2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34943238

RESUMO

The Asian Central Steppe, consisting of current-day Kazakhstan and Russia, has acted as a highway for major migrations throughout history. Therefore, describing the genetic composition of past populations in Central Asia holds value to understanding human mobility in this pivotal region. In this study, we analyse paleogenomic data generated from five humans from Kuygenzhar, Kazakhstan. These individuals date to the early to mid-18th century, shortly after the Kazakh Khanate was founded, a union of nomadic tribes of Mongol Golden Horde and Turkic origins. Genomic analysis identifies that these individuals are admixed with varying proportions of East Asian ancestry, indicating a recent admixture event from East Asia. The high amounts of DNA from the anaerobic Gram-negative bacteria Tannerella forsythia, a periodontal pathogen, recovered from their teeth suggest they may have suffered from periodontitis disease. Genomic analysis of this bacterium identified recently evolved virulence and glycosylation genes including the presence of antibiotic resistance genes predating the antibiotic era. This study provides an integrated analysis of individuals with a diet mostly based on meat (mainly horse and lamb), milk, and dairy products and their oral microbiome.

4.
Ann Hum Biol ; 48(3): 260-269, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34459343

RESUMO

BACKGROUND: Thanks to the availability of rich surname, linguistic and genetic information, together with its geographic and cultural complexity, Trentino (North-Eastern Italy) is an ideal place to test the relationships between genetic and cultural traits. AIM: We provide a comprehensive study of population structures based on surname and dialect variability and evaluate their relationships with genetic diversity in Trentino. SUBJECTS AND METHODS: Surname data were collected for 363 parishes, linguistic data for 57 dialects and genetic data for different sets of molecular markers (Y-chromosome, mtDNA, autosomal) in 10 populations. Analyses relied on different multivariate methods and correlation tests. RESULTS: Besides the expected isolation-by-distance-like patterns (with few local exceptions, likely related to sociocultural instances), we detected a significant and geography-independent association between dialects and surnames. As for molecular markers, only Y-chromosomal STRs seem to be associated with the dialects, although no significant result was obtained. No evidence for correlation between molecular markers and surnames was observed. CONCLUSION: Surnames act as cultural markers as do other words, although in this context they cannot be used as reliable proxies for genetic variability at a local scale.


Assuntos
DNA/análise , Variação Genética , Idioma , Nomes , Cultura , Humanos , Itália
5.
Am J Phys Anthropol ; 175(3): 665-679, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33969895

RESUMO

OBJECTIVES: Genetic drift and admixture are driving forces in human evolution, but their concerted impact to population evolution in historical times and at a micro-geographic scale is poorly assessed. In this study we test a demographic model encompassing both admixture and drift to the case of social-cultural isolates such as the so-called "Commons." MATERIALS AND METHODS: Commons are peculiar institutions of medieval origins whose key feature is the tight relationship between population and territory, mediated by the collective property of shared resources. Here, we analyze the Y-chromosomal genetic structure of four Commons (for a total of 366 samples) from the Central and Eastern Padana plain in Northern Italy. RESULTS: Our results reveal that all these groups exhibit patterns of significant diversity reduction, peripheral/outlier position within the Italian/European genetic space and high frequency of Common-specific haplogroups. By explicitly testing different drift-admixture models, we show that a drift-only model is more probable for Central Padana Commons, while additional admixture (~20%) from external population around the same time of their foundation cannot be excluded for the Eastern ones. DISCUSSION: Building on these results, we suggest central Middle Ages as the most probable age of foundation for three of the considered Commons, the remaining one pointing to late antiquity. We conclude that an admixture-drift model is particularly useful for interpreting the genetic structure and recent demographic history of small-scale populations in which social-cultural features play a significant role.


Assuntos
Cromossomos Humanos Y , Deriva Genética , Cromossomos Humanos Y/genética , Variação Genética/genética , Genética Populacional , Haplótipos , Humanos , Itália
6.
Elife ; 102021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33941312

RESUMO

Extreme longevity is the paradigm of healthy aging as individuals who reached the extreme decades of human life avoided or largely postponed all major age-related diseases. In this study, we sequenced at high coverage (90X) the whole genome of 81 semi-supercentenarians and supercentenarians [105+/110+] (mean age: 106.6 ± 1.6) and of 36 healthy unrelated geographically matched controls (mean age 68.0 ± 5.9) recruited in Italy. The results showed that 105+/110+ are characterized by a peculiar genetic background associated with efficient DNA repair mechanisms, as evidenced by both germline data (common and rare variants) and somatic mutations patterns (lower mutation load if compared to younger healthy controls). Results were replicated in a second independent cohort of 333 Italian centenarians and 358 geographically matched controls. The genetics of 105+/110+ identified DNA repair and clonal haematopoiesis as crucial players for healthy aging and for the protection from cardiovascular events.


Assuntos
Hematopoiese Clonal/genética , Reparo do DNA , Longevidade/genética , Sequenciamento Completo do Genoma/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Patrimônio Genético , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Mutação , Sequenciamento Completo do Genoma/métodos
7.
Evol Appl ; 14(2): 297-313, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33664777

RESUMO

Adoption of diets based on some cereals, especially on rice, signified an iconic change in nutritional habits for many Asian populations and a relevant challenge for their capability to maintain glucose homeostasis. Indeed, rice shows the highest carbohydrates content and glycemic index among the domesticated cereals and its usual ingestion represents a potential risk factor for developing insulin resistance and related metabolic diseases. Nevertheless, type 2 diabetes and obesity epidemiological patterns differ among Asian populations that rely on rice as a staple food, with higher diabetes prevalence and increased levels of central adiposity observed in people of South Asian ancestry rather than in East Asians. This may be at least partly due to the fact that populations from East Asian regions where wild rice or other cereals such as millet have been already consumed before their cultivation and/or were early domesticated have relied on these nutritional resources for a period long enough to have possibly evolved biological adaptations that counteract their detrimental side effects. To test such a hypothesis, we compared adaptive evolution of these populations with that of control groups from regions where the adoption of cereal-based diets occurred many thousand years later and which were identified from a genome-wide dataset including 2,379 individuals from 124 East Asian and South Asian populations. This revealed selective sweeps and polygenic adaptive mechanisms affecting functional pathways involved in fatty acids metabolism, cholesterol/triglycerides biosynthesis from carbohydrates, regulation of glucose homeostasis, and production of retinoic acid in Chinese Han and Tujia ethnic groups, as well as in people of Korean and Japanese ancestry. Accordingly, long-standing rice- and/or millet-based diets have possibly contributed to trigger the evolution of such biological adaptations, which might represent one of the factors that play a role in mitigating the metabolic risk of these East Asian populations.

8.
Sci Rep ; 11(1): 3045, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542324

RESUMO

Calabrian Greeks are an enigmatic population that have preserved and evolved a unique variety of language, Greco, survived in the isolated Aspromonte mountain area of Southern Italy. To understand their genetic ancestry and explore possible effects of geographic and cultural isolation, we genome-wide genotyped a large set of South Italian samples including both communities that still speak Greco nowadays and those that lost the use of this language earlier in time. Comparisons with modern and ancient populations highlighted ancient, long-lasting genetic links with Eastern Mediterranean and Caucasian/Near-Eastern groups as ancestral sources of Southern Italians. Our results suggest that the Aspromonte communities might be interpreted as genetically drifted remnants that departed from such ancient genetic background as a consequence of long-term isolation. Specific patterns of population structuring and higher levels of genetic drift were indeed observed in these populations, reflecting geographic isolation amplified by cultural differences in the groups that still conserve the Greco language. Isolation and drift also affected the current genetic differentiation at specific gene pathways, prompting for future genome-wide association studies aimed at exploring trait-related loci that have drifted up in frequency in these isolated groups.


Assuntos
Cromossomos Humanos Y/genética , DNA Mitocondrial/genética , Genética Populacional , Genoma Humano/genética , DNA Antigo/análise , Deriva Genética , Genótipo , Grécia , Haplótipos/genética , História Antiga , Humanos , Itália , Idioma , População Branca/genética
9.
BMC Biol ; 18(1): 51, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32438927

RESUMO

BACKGROUND: The cline of human genetic diversity observable across Europe is recapitulated at a micro-geographic scale by variation within the Italian population. Besides resulting from extensive gene flow, this might be ascribable also to local adaptations to diverse ecological contexts evolved by people who anciently spread along the Italian Peninsula. Dissecting the evolutionary history of the ancestors of present-day Italians may thus improve the understanding of demographic and biological processes that contributed to shape the gene pool of European populations. However, previous SNP array-based studies failed to investigate the full spectrum of Italian variation, generally neglecting low-frequency genetic variants and examining a limited set of small effect size alleles, which may represent important determinants of population structure and complex adaptive traits. To overcome these issues, we analyzed 38 high-coverage whole-genome sequences representative of population clusters at the opposite ends of the cline of Italian variation, along with a large panel of modern and ancient Euro-Mediterranean genomes. RESULTS: We provided evidence for the early divergence of Italian groups dating back to the Late Glacial and for Neolithic and distinct Bronze Age migrations having further differentiated their gene pools. We inferred adaptive evolution at insulin-related loci in people from Italian regions with a temperate climate, while possible adaptations to pathogens and ultraviolet radiation were observed in Mediterranean Italians. Some of these adaptive events may also have secondarily modulated population disease or longevity predisposition. CONCLUSIONS: We disentangled the contribution of multiple migratory and adaptive events in shaping the heterogeneous Italian genomic background, which exemplify population dynamics and gene-environment interactions that played significant roles also in the formation of the Continental and Southern European genomic landscapes.


Assuntos
Evolução Molecular , Variação Genética , Genoma Humano , Arqueologia , DNA Antigo/análise , Humanos , Itália , População Branca
10.
J Anthropol Sci ; 96: 189-208, 2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31782749

RESUMO

Human populations living at high altitude evolved a number of biological adjustments to cope with a challenging environment characterised especially by reduced oxygen availability and limited nutritional resources. This condition may also affect their gut microbiota composition. Here, we explored the impact of exposure to such selective pressures on human gut microbiota by considering different ethnic groups living at variable degrees of altitude: the high-altitude Sherpa and low-altitude Tamang populations from Nepal, the high-altitude Aymara population from Bolivia, as well as a low-altitude cohort of European ancestry, used as control. We thus observed microbial profiles common to the Sherpa and Aymara, but absent in the low-altitude cohorts, which may contribute to the achievement of adaptation to high-altitude lifestyle and nutritional conditions. The collected evidences suggest that microbial signatures associated to these rural populations may enhance metabolic functions able to supply essential compounds useful for the host to cope with high altitude-related physiological changes and energy demand. Therefore, these results add another valuable piece of the puzzle to the understanding of the beneficial effects of symbiosis between microbes and their human host even from an evolutionary perspective.


Assuntos
Adaptação Fisiológica/fisiologia , Dieta/estatística & dados numéricos , Microbioma Gastrointestinal/fisiologia , Estilo de Vida/etnologia , Montanhismo/fisiologia , Adulto , Altitude , Evolução Biológica , Bolívia/etnologia , Feminino , Humanos , Masculino , Nepal/etnologia , Adulto Jovem
11.
Mol Biol Evol ; 36(6): 1254-1269, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30895292

RESUMO

Extensive European and African admixture coupled with loss of Amerindian lineages makes the reconstruction of pre-Columbian history of Native Americans based on present-day genomes extremely challenging. Still open questions remain about the dispersals that occurred throughout the continent after the initial peopling from the Beringia, especially concerning the number and dynamics of diffusions into South America. Indeed, if environmental and historical factors contributed to shape distinct gene pools in the Andes and Amazonia, the origins of this East-West genetic structure and the extension of further interactions between populations residing along this divide are still not well understood. To this end, we generated new high-resolution genome-wide data for 229 individuals representative of one Central and ten South Amerindian ethnic groups from Mexico, Peru, Bolivia, and Argentina. Low levels of European and African admixture in the sampled individuals allowed the application of fine-scale haplotype-based methods and demographic modeling approaches. These analyses revealed highly specific Native American genetic ancestries and great intragroup homogeneity, along with limited traces of gene flow mainly from the Andes into Peruvian Amazonians. Substantial amount of genetic drift differentially experienced by the considered populations underlined distinct patterns of recent inbreeding or prolonged isolation. Overall, our results support the hypothesis that all non-Andean South Americans are compatible with descending from a common lineage, while we found low support for common Mesoamerican ancestors of both Andeans and other South American groups. These findings suggest extensive back-migrations into Central America from non-Andean sources or conceal distinct peopling events into the Southern Continent.


Assuntos
Genoma Humano , Migração Humana , Indígenas Sul-Americanos/genética , Fluxo Gênico , Variação Genética , Haplótipos , Humanos , Modelos Genéticos , Filogeografia , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal , América do Sul
12.
Am J Phys Anthropol ; 168(4): 717-728, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30693949

RESUMO

OBJECTIVES: The Yaghnobis are an ethno-linguistic minority historically settled along the Yaghnob River in the Upper-Zarafshan Valley in Tajikistan. They speak a language of Old Sogdian origin, which is the only present-day witness of the Lingua Franca used along the Silk Road in Late Antiquity. The aim of this study was to reconstruct the genetic history of this community in order to shed light on its isolation and genetic ancestry within the Euro-Asiatic context. MATERIALS AND METHODS: A total of 100 DNA samples were collected in the Yaghnob and Matcha Valleys during several expeditions and their mitochondrial, Y-chromosome and autosomal genome-wide variation were compared with that from a large set of modern and ancient Euro-Asiatic samples. RESULTS: Findings from uniparental markers highlighted the long-term isolation of the Yaghnobis. Mitochondrial DNA ancestry traced an ancient link with Middle Eastern populations, whereas Y-chromosome legacy showed more tight relationships with Central Asians. Admixture, outgroup-f3, and D-statistics computed on autosomal variation corroborated Y-chromosome evidence, pointing respectively to low Anatolian Neolithic and high Steppe ancestry proportions in Yaghnobis, and to their closer affinity with Tajiks than to Iranians. DISCUSSION: Although the Yaghnobis do not show evident signs of recent admixture, they could be considered a modern proxy for the source of gene flow for many Central Asian and Middle Eastern groups. Accordingly, they seem to retain a peculiar genomic ancestry probably ascribable to an ancient gene pool originally wide spread across a vast area and subsequently reshuffled by distinct demographic events occurred in Middle East and Central Asia.


Assuntos
Povo Asiático/genética , Etnicidade/genética , População Branca/genética , Antropologia Física , Cromossomos Humanos Y/genética , DNA Mitocondrial/genética , Migração Humana , Humanos , Masculino , Metagenômica , Polimorfismo de Nucleotídeo Único/genética , Tadjiquistão
13.
Genome Biol Evol ; 10(11): 2919-2930, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30335146

RESUMO

Although Tibetans and Sherpa present several physiological adjustments evolved to cope with selective pressures imposed by the high-altitude environment, especially hypobaric hypoxia, few selective sweeps at a limited number of hypoxia related genes were confirmed by multiple genomic studies. Nevertheless, variants at these loci were found to be associated only with downregulation of the erythropoietic cascade, which represents an indirect aspect of the considered adaptive phenotype. Accordingly, the genetic basis of Tibetan/Sherpa adaptive traits remains to be fully elucidated, in part due to limitations of selection scans implemented so far and mostly relying on the hard sweep model.In order to overcome this issue, we used whole-genome sequence data and several selection statistics as input for gene network analyses aimed at testing for the occurrence of polygenic adaptation in these high-altitude Himalayan populations. Being able to detect also subtle genomic signatures ascribable to weak positive selection at multiple genes of the same functional subnetwork, this approach allowed us to infer adaptive evolution at loci individually showing small effect sizes, but belonging to highly interconnected biological pathways overall involved in angiogenetic processes.Therefore, these findings pinpointed a series of selective events neglected so far, which likely contributed to the augmented tissue blood perfusion observed in Tibetans and Sherpa, thus uncovering the genetic determinants of a key biological mechanism that underlies their adaptation to high altitude.


Assuntos
Adaptação Biológica , Altitude , Genoma Humano , Herança Multifatorial , Seleção Genética , Humanos , Família Multigênica , Nepal , Fenótipo , Tibet
14.
Aging (Albany NY) ; 10(8): 1947-1963, 2018 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-30089705

RESUMO

The study of the genetics of longevity has been mainly addressed by GWASs that considered subjects from different populations to reach higher statistical power. The "price to pay" is that population-specific evolutionary histories and trade-offs were neglected in the investigation of gene-environment interactions. We propose a new "diachronic" approach that considers processes occurred at both evolutionary and lifespan timescales. We focused on a well-characterized population in terms of evolutionary history (i.e. Italians) and we generated genome-wide data for 333 centenarians from the peninsula and 773 geographically-matched healthy individuals. Obtained results showed that: (i) centenarian genomes are enriched for an ancestral component likely shaped by pre-Neolithic migrations; (ii) centenarians born in Northern Italy unexpectedly clustered with controls from Central/Southern Italy suggesting that Neolithic and Bronze Age gene flow did not favor longevity in this population; (iii) local past adaptive events in response to pathogens and targeting arachidonic acid metabolism became favorable for longevity; (iv) lifelong changes in the frequency of several alleles revealed pleiotropy and trade-off mechanisms crucial for longevity. Therefore, we propose that demographic history and ancient/recent population dynamics need to be properly considered to identify genes involved in longevity, which can differ in different temporal/spatial settings.


Assuntos
Genótipo , Longevidade/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Dinâmica Populacional
15.
Mob DNA ; 9: 28, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30147753

RESUMO

BACKGROUND: Transposable elements are biologically important components of eukaryote genomes. In particular, non-LTR retrotransposons (N-LTRrs) played a key role in shaping the human genome throughout evolution. In this study, we compared retrotransposon insertions differentially present in the genomes of Anatomically Modern Humans, Neanderthals, Denisovans and Chimpanzees, in order to assess the possible impact of retrotransposition in the differentiation of the human lineage. RESULTS: We first identified species-specific N-LTRrs and established their distribution in present day human populations. These analyses shortlisted a group of N-LTRr insertions that were found exclusively in Anatomically Modern Humans. These insertions are associated with an increase in the number of transcriptional/splicing variants of those genes they inserted in. The analysis of the functionality of genes containing human-specific N-LTRr insertions reflects changes that occurred during human evolution. In particular, the expression of genes containing the most recent N-LTRr insertions is enriched in the brain, especially in undifferentiated neurons, and these genes associate in networks related to neuron maturation and migration. Additionally, we identified candidate N-LTRr insertions that have likely produced new functional variants exclusive to modern humans, whose genomic loci show traces of positive selection. CONCLUSIONS: Our results strongly suggest that N-LTRr impacted our differentiation as a species, most likely inducing an increase in neural complexity, and have been a constant source of genomic variability all throughout the evolution of the human lineage.

16.
Ann Hum Biol ; 45(1): 57-65, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29183201

RESUMO

BACKGROUND: Southern Italy and Sicily played a key role in the peopling history of the Mediterranean. While genetic research showed the remarkable homogeneity of these regions, surname-based studies instead suggested low population mobility, hence potential structuring. AIM: In order to better understand these different patterns, this study (1) thoroughly analysed the surname structure of Sicily and Southern Italy and (2) tested its relationships with a wide set of molecular markers. SUBJECTS AND METHODS: Surname data were collected from 1213 municipalities and compared to uniparental and autosomal genetic markers typed in ∼300 individuals from 8-10 populations. Surname analyses were performed using different multivariate methods, while comparisons with genetic data relied on correlation tests. RESULTS: Surnames were clearly structured according to regional geographic patterns, which likely emerged because of recent isolation-by-distance-like population dynamics. In general, genetic markers, hinting at a pervasive homogeneity, did not correlate with surname distribution. However, long autosomal haplotypes (>5 cM) that compared to genotypic (SNPs) data identify more "recent" relatedness, showing a clear association with surname patterns. CONCLUSION: The apparent contradiction between surname structure and genetic homogeneity was resolved by figuring surnames as recent "ripples" deposited on a vast and ancient homogeneous genetic "surface".


Assuntos
Variação Genética , Haplótipos , Dinâmica Populacional , Marcadores Genéticos , Humanos , Itália , Nomes , Sicília
17.
Sci Rep ; 7(1): 15512, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29138459

RESUMO

While much research attention has focused on demographic processes that enabled human diffusion on the Tibetan plateau, little is known about more recent colonization of Southern Himalayas. In particular, the history of migrations, admixture and/or isolation of populations speaking Tibeto-Burman languages, which is supposed to be quite complex and to have reshaped patterns of genetic variation on both sides of the Himalayan arc, remains only partially elucidated. We thus described the genomic landscape of previously unsurveyed Tibeto-Burman (i.e. Sherpa and Tamang) and Indo-Aryan communities from remote Nepalese valleys. Exploration of their genomic relationships with South/East Asian populations provided evidence for Tibetan admixture with low-altitude East Asians and for Sherpa isolation. We also showed that the other Southern Himalayan Tibeto-Burmans derived East Asian ancestry not from the Tibetan/Sherpa lineage, but from low-altitude ancestors who migrated from China plausibly across Northern India/Myanmar, having experienced extensive admixture that reshuffled the ancestral Tibeto-Burman gene pool. These findings improved the understanding of the impact of gene flow/drift on the evolution of high-altitude Himalayan peoples and shed light on migration events that drove colonization of the southern Himalayan slopes, as well as on the role played by different Tibeto-Burman groups in such a complex demographic scenario.


Assuntos
DNA/genética , Etnicidade/genética , Fluxo Gênico , Deriva Genética , Migração Humana/tendências , DNA/classificação , Etnicidade/estatística & dados numéricos , Feminino , Variação Genética , Humanos , Índia , Masculino , Mianmar , Nepal , Filogeografia , Tibet
19.
Proc Natl Acad Sci U S A ; 114(34): 9140-9145, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28784786

RESUMO

Observable patterns of cultural variation are consistently intertwined with demic movements, cultural diffusion, and adaptation to different ecological contexts [Cavalli-Sforza and Feldman (1981) Cultural Transmission and Evolution: A Quantitative Approach; Boyd and Richerson (1985) Culture and the Evolutionary Process]. The quantitative study of gene-culture coevolution has focused in particular on the mechanisms responsible for change in frequency and attributes of cultural traits, the spread of cultural information through demic and cultural diffusion, and detecting relationships between genetic and cultural lineages. Here, we make use of worldwide whole-genome sequences [Pagani et al. (2016) Nature 538:238-242] to assess the impact of processes involving population movement and replacement on cultural diversity, focusing on the variability observed in folktale traditions (n = 596) [Uther (2004) The Types of International Folktales: A Classification and Bibliography. Based on the System of Antti Aarne and Stith Thompson] in Eurasia. We find that a model of cultural diffusion predicted by isolation-by-distance alone is not sufficient to explain the observed patterns, especially at small spatial scales (up to [Formula: see text]4,000 km). We also provide an empirical approach to infer presence and impact of ethnolinguistic barriers preventing the unbiased transmission of both genetic and cultural information. After correcting for the effect of ethnolinguistic boundaries, we show that, of the alternative models that we propose, the one entailing cultural diffusion biased by linguistic differences is the most plausible. Additionally, we identify 15 tales that are more likely to be predominantly transmitted through population movement and replacement and locate putative focal areas for a set of tales that are spread worldwide.


Assuntos
Evolução Cultural , Folclore , Genética Populacional/métodos , Genômica/métodos , África , Ásia , Evolução Biológica , Europa (Continente) , Geografia , Humanos , Linguística , Modelos Teóricos
20.
Sci Rep ; 7(1): 1984, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28512355

RESUMO

The Mediterranean shores stretching between Sicily, Southern Italy and the Southern Balkans witnessed a long series of migration processes and cultural exchanges. Accordingly, present-day population diversity is composed by multiple genetic layers, which make the deciphering of different ancestral and historical contributes particularly challenging. We address this issue by genotyping 511 samples from 23 populations of Sicily, Southern Italy, Greece and Albania with the Illumina GenoChip Array, also including new samples from Albanian- and Greek-speaking ethno-linguistic minorities of Southern Italy. Our results reveal a shared Mediterranean genetic continuity, extending from Sicily to Cyprus, where Southern Italian populations appear genetically closer to Greek-speaking islands than to continental Greece. Besides a predominant Neolithic background, we identify traces of Post-Neolithic Levantine- and Caucasus-related ancestries, compatible with maritime Bronze-Age migrations. We argue that these results may have important implications in the cultural history of Europe, such as in the diffusion of some Indo-European languages. Instead, recent historical expansions from North-Eastern Europe account for the observed differentiation of present-day continental Southern Balkan groups. Patterns of IBD-sharing directly reconnect Albanian-speaking Arbereshe with a recent Balkan-source origin, while Greek-speaking communities of Southern Italy cluster with their Italian-speaking neighbours suggesting a long-term history of presence in Southern Italy.

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