La evidencia molecular del poblamiento humano de América

Se revisan someramente los aportes de la arqueología, la lingüística histórica y la bioantropología al estudio del origen de las poblaciones nativas americanas, y se profundiza en aquellos aspectos derivados del estudio de la información albergada en macromoléculas biológicas, recuperada tanto a partir de individuos contemporáneos como de individuos antiguos. Diversas líneas de evidencia confirman el origen asiático y reciente de las poblaciones indígenas americanas, como así también su escasa diversidad genética relativaThe contributions of Archaeology, Historical Linguistics and Bioanthropology to the study of the origin of Native Americans are briefly reviewed, and a more deep coverage is given to those studies based on information retrieved from biological macromolecules derived from both extant and extinct individuals. Different lines of evidence confirm the Asiatic affinities and the recent origin of the indigenous American populations, as well as its relatively low genetic diversity.Fil: Bravi, Claudio Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

Beringian standstill and spread of native American founders

Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the intial colonization of the Americas remain unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic.La lista completa de autores que integran el documento puede consultarse en el archivo.Instituto Multidisciplinario de Biología CelularFacultad de Ciencias Naturales y Muse

Beringian standstill and spread of native American founders

Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the intial colonization of the Americas remain unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic.La lista completa de autores que integran el documento puede consultarse en el archivo.Instituto Multidisciplinario de Biología CelularFacultad de Ciencias Naturales y Muse

La evidencia molecular del poblamiento humano de América

Se revisan someramente los aportes de la arqueología, la lingüística histórica y la bioantropología al estudio del origen de las poblaciones nativas americanas, y se profundiza en aquellos aspectos derivados del estudio de la información albergada en macromoléculas biológicas, recuperada tanto a partir de individuos contemporáneos como de individuos antiguos. Diversas líneas de evidencia confirman el origen asiático y reciente de las poblaciones indígenas americanas, como así también su escasa diversidad genética relativa.The contributions of Archaeology, Historical Linguistics and Bioanthropology to the study of the origin of Native Americans are briefly reviewed, and a more deep coverage is given to those studies based on information retrieved from biological macromolecules derived from both extant and extinct individuals. Different lines of evidence confirm the Asiatic affinities and the recent origin of the indigenous American populations, as well as its relatively low genetic diversity.Facultad de Ciencias Naturales y Muse

Beringian standstill and spread of native American founders

Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the intial colonization of the Americas remain unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic.La lista completa de autores que integran el documento puede consultarse en el archivo.Instituto Multidisciplinario de Biología CelularFacultad de Ciencias Naturales y Muse

The Simons Genome Diversity Project : 300 genomes from 142 diverse populations.

Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioural modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that of other non-Africans.Facultad de Ciencias Naturales y Muse

La evidencia molecular del poblamiento humano de América

Se revisan someramente los aportes de la arqueología, la lingüística histórica y la bioantropología al estudio del origen de las poblaciones nativas americanas, y se profundiza en aquellos aspectos derivados del estudio de la información albergada en macromoléculas biológicas, recuperada tanto a partir de individuos contemporáneos como de individuos antiguos. Diversas líneas de evidencia confirman el origen asiático y reciente de las poblaciones indígenas americanas, como así también su escasa diversidad genética relativa.The contributions of Archaeology, Historical Linguistics and Bioanthropology to the study of the origin of Native Americans are briefly reviewed, and a more deep coverage is given to those studies based on information retrieved from biological macromolecules derived from both extant and extinct individuals. Different lines of evidence confirm the Asiatic affinities and the recent origin of the indigenous American populations, as well as its relatively low genetic diversity.Facultad de Ciencias Naturales y Muse

¿Convergencia o polifiletismo en la evidencia mitocondrial del poblamiento americano?

El ADN mitocondrial es quizás el locus más frecuentemente utilizado en estudios de filogeografía humana. Más de 2000 secuencias de la Región Hipervariable I se han obtenido en poblaciones indígenas o criollas americanas, distribuidas en 5 grupos de linajes maternos, los haplogrupos ABCD y X. El análisis de otras ~800 secuencias mitocondriales (casi)completas ha permitido establecer una filogenia absoluta del árbol mitocondrial humano. El análisis de la información disponible ha permitido establecer que, contra las interpretaciones prevalentes, las secuencias americanas atribuibles al haplogrupo D pertenecen a cuatro grupos monofiléticos de distribución recíprocamente disyunta: dos linajes sólo se hallan en poblaciones Na-Denes y Eskimo-Aleutianas, mientras que los otros dos están restringidos a las amerindias.En esta contribución se discute el hallazgo de un grupo de linajes mitocondriales que bien puede ser tan sólo una diferenciación regional de uno de los cuatro grupos mencionados antes o bien constituír un quinto linaje fundador para el haplogrupo D en América.Asociación de Antropología Biológica de la República Argentin

¿Convergencia o polifiletismo en la evidencia mitocondrial del poblamiento americano?

El ADN mitocondrial es quizás el locus más frecuentemente utilizado en estudios de filogeografía humana. Más de 2000 secuencias de la Región Hipervariable I se han obtenido en poblaciones indígenas o criollas americanas, distribuidas en 5 grupos de linajes maternos, los haplogrupos ABCD y X. El análisis de otras ~800 secuencias mitocondriales (casi)completas ha permitido establecer una filogenia absoluta del árbol mitocondrial humano. El análisis de la información disponible ha permitido establecer que, contra las interpretaciones prevalentes, las secuencias americanas atribuibles al haplogrupo D pertenecen a cuatro grupos monofiléticos de distribución recíprocamente disyunta: dos linajes sólo se hallan en poblaciones Na-Denes y Eskimo-Aleutianas, mientras que los otros dos están restringidos a las amerindias.En esta contribución se discute el hallazgo de un grupo de linajes mitocondriales que bien puede ser tan sólo una diferenciación regional de uno de los cuatro grupos mencionados antes o bien constituír un quinto linaje fundador para el haplogrupo D en América.Asociación de Antropología Biológica de la República Argentin

What is a 'novel' mtDNA mutation - And does 'novelty' really matter?

The hunt for pathogenic mitochondrial DNA (mtDNA) mutations is often fueled by the seeming novelty of mutations that are either nonsynonymous or affect the protein synthesis machinery in patients. In order to determine the novelty of a detected mutation, the working geneticist nearly always consults MITOMAP - often exclusively. By reanalyzing some case studies of refractory anemia with ring sideroblasts, prostate cancer, and hearing impairment, we demonstrate that the practice of solely relying on MITOMAP can be most misleading. A notorious example is the T1243C mutation, which was assessed to be novel and deemed to be associated with some (rare) disease simply because researchers did not realize that T1243C defines a deep branch in the Eurasian mtDNA phylogeny. The majority of 'novel' mutations suspected of being pathogenic are in actual fact known (and presumably neutral) polymorphisms (although unknown to MITOMAP), and this becomes glaringly evident when proper database searches and straightforward Internet queries are carried out.Instituto Multidisciplinario de Biología Celula