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March 16, 2010

The Genetic History of the Americas


This interesting review is part of a special number published on Current Biology, 23 February, 2010 Volume 20, Issue 4. They concluded that:
The Americas, the last continents to be entered by modern humans, were colonized during the late Pleistocene via a land bridge across what is now the Bering strait. However, the timing and nature of the initial colonization events remain contentious. The Asian origin of the earliest Americans has been amply established by numerous classical marker studies of the mid-twentieth century.
More recently, mtDNA sequences, Y-chromosome and autosomal marker studies have provided a higher level of resolution in confirming the Asian origin of indigenous Americans and provided more precise time estimates for the emergence of Native Americans. But these data raise many additional questions regarding source populations, number and size of colonizing groups and the points of entry to the Americas.
Rapidly accumulating molecular data from populations throughout the Americas, increased use of demographic models to test alternative colonization scenarios, and evaluation of the concordance of archaeological, paleoenvironmental and genetic data provide optimism for a fuller understanding of the initial colonization of the Americas.

In the figure, it can see the hypothesized routes for original migration into the Americas.The Beringian and Pacific coastal routes (blue and yellow, respectively) may have been roughly contemporaneous following the Last Glacial Maximum (LGM), although contemporaneity is not certain. The more hypothetical northern migration path (red) implies a pre-LGM population movement. These migration paths need not be considered mutually exclusive.
Complete agreement between mtDNA, Y-chromosomal DNA and autosomal genetic systems has not yet been realized with respect to colonization models, although all three are consistent in failing to support the ‘blitzkrieg’ or ‘three-wave’ migration models. Nevertheless, these models and their underlying assumptions continue to be used as the framework for hypothesis testing in American colonization scenarios. There is an unquestionable need for more genetic data from under-sampled geographic regions, as well as from more, and more widely dispersed, ancient populations. Because of the presumed nature of the colonization, reconstructing the genetic history of the Americas should be relatively simple compared to the challenges presented by other continents, but genetic analyses of American populations continue to be hindered by inadequate geographic (and temporal) sampling, lack of standardization of analytical methods, and the heterogeneous patchwork of diversity resulting from post-contact admixture.
You can see the complete issue at:
Archaeogenetics, Towards a ‘New Synthesis’?
The Evolution of Human Genetic and Phenotypic Variation in Africa
Archaeogenetics of Europe
The Human Genetic History of South Asia
The Human Genetic History of East Asia: Weaving a Complex Tapestry
The Human Genetic History of Oceania: Near and Remote Views of Dispersal
The Genetics of Human Adaptation: Hard Sweeps, Soft Sweeps, and Polygenic Adaptation
A very interesting conclusion, America is a complete challenge in population genetic research...

Latinamerican School of Medical Genetics - ELAG 2010

The 6th Edition of the ELAG is programmed to May 9th to 15th 2010 in Caxias do Sul, RS, Brasil. It counts with 30 lecturers and 70 fellows. The Programme comprises: an inaugural lecture, six symposia (with four lectures each one), one debate, one workshop with two lectures and four practical workshops, in summary, 70 different activities,

You can ask for more information to: Priscila Correa,
elag@ufrgs.br
Medical Genetics Services
Hospital de Clínicas de Porto Alegre
Rua Ramiro Barcelos, 2350, CEP 90035-903
Porto Alegre- Rio Grande do Sul (BRASIL)
Phone: +55-51-3359-8011, Fax: +55-51-3359-8010
Among the themes it will discuss:

Genetic and genomics, The new world of RNAs, Proteomics, Epigenetics, Genetic of Latin-American populations, Poulation genetics and medicine, Bioinformatics, Genetics of development, Neurogenetics, Molecular mechanisn of the skeletal dysplasias, New techniques in genomic analysis, Oncogenetics, Funtional genetics, Prenatal Diagnostic, Population triage, Genetic therapy, Enzimatic reparation, Cell therapy, Pre-syimptomatic diagnostic an predictive medicine, Ethics and genetic revolution
Mini-Curso 1: Genetic epidemiology

Mini-Curso 2: New technologies of genbetic and genomic research

Mini-Curso 3: Genetic counselling

Mini-Curso 4: Therapeutic strategies

Professors - Brasil

Patrícia ASHTON-PROLLA (Porto Alegre), Paulo BISCH (Rio de Janeiro), Eduardo CASTILLA (Rio de Janeiro), Roberto GIUGLIANI (Porto Alegre), José Roberto GOLDIM (Porto Alegre), Laura JARDIM (Porto Alegre), Rafael LINDEN (Rio de Janeiro), Iscia LOPES-CENDES (São Paulo), Ursula MATTE (Porto Alegre), Ieda ORIOLI (Rio de Janeiro), João Bosco PESQUERO (São Paulo), Mariluce RIEGEL (Porto Alegre), Francisco SALZANO (Porto Alegre), Lavinia SCHULER-FACCINI (P. Alegre), Fernando VARGAS (Rio de Janeiro)
Professores - América Latina
Juan Francisco CABELLO (Chile), Jorge LOPEZ-CAMELO (Argentina), Alberto Santiago CORNIER (P. Rico), Juan GILLI (Argentina), Gerardo JIMENEZ ARCE (Costa Rica), Alejandro GIRALDO (Colombia), Hugo KUPRITZKI (Argentina), Jose MINGUELL (Chile), Rocio ORTIZ (México), Cezar PAZ Y MINO (Equador), Augusto ROJAS-MARTINEZ (México), Fernando POLETTA (Argentina), Felix RECILLAS-TARGA (México), Manuel SABORÍO (Costa Rica)