Apellidos, estructura genética y dinámica evolutiva de la Argentina

Los apellidos proporcionan una estimación de la estructura genética de las poblaciones humanas, de su consanguinidad y aislamiento. En este trabajo se analizó la distribución de los apellidos de 22,6 millones de electores, registrados en el Padrón Electoral Nacional (2000-2001) agrupados en 24 distritos, para cada uno de los cuales se calculó el coeficiente de consanguinidad por isonimia al azar (FST), el indicador de migración reciente (ν) y la diversidad de apellidos (α). Se calcularon las distancias isonímicas con las que se construyó un dendograma. Se encontraron 414.441 apellidos diferentes, siendo González el más común. Los apellidos más frecuentes de la Argentina son todos de origen ibérico, sin embargo, sólo 41 de ellos figuran entre los 100 más frecuentes en España. Los valores más elevados de FST se presentaron en La Rioja, Corrientes y Santiago del Estero, y los más bajos en Capital Federal, Río Negro, La Pampa, Buenos Aires y Santa Fé. La distribución geográfica de los valores de α presentó un gradiente decreciente desde el Atlántico hacia el sur y hacia los Andes lo que indicaría un gradiente temporal en el asentamiento de los inmigrantes. Los agrupamientos del dendograma coinciden con las grandes regiones geográficas de la Argentina. Los parámetros isonímicos empleados permiten describir adecuadamente la estructura genética de la Argentina y coinciden con las particularidades de su poblamiento.Asociación de Antropología Biológica de la República Argentin

Apellidos, estructura genética y dinámica evolutiva de la Argentina

Los apellidos proporcionan una estimación de la estructura genética de las poblaciones humanas, de su consanguinidad y aislamiento. En este trabajo se analizó la distribución de los apellidos de 22,6 millones de electores, registrados en el Padrón Electoral Nacional (2000-2001) agrupados en 24 distritos, para cada uno de los cuales se calculó el coeficiente de consanguinidad por isonimia al azar (FST), el indicador de migración reciente (ν) y la diversidad de apellidos (α). Se calcularon las distancias isonímicas con las que se construyó un dendograma. Se encontraron 414.441 apellidos diferentes, siendo González el más común. Los apellidos más frecuentes de la Argentina son todos de origen ibérico, sin embargo, sólo 41 de ellos figuran entre los 100 más frecuentes en España. Los valores más elevados de FST se presentaron en La Rioja, Corrientes y Santiago del Estero, y los más bajos en Capital Federal, Río Negro, La Pampa, Buenos Aires y Santa Fé. La distribución geográfica de los valores de α presentó un gradiente decreciente desde el Atlántico hacia el sur y hacia los Andes lo que indicaría un gradiente temporal en el asentamiento de los inmigrantes. Los agrupamientos del dendograma coinciden con las grandes regiones geográficas de la Argentina. Los parámetros isonímicos empleados permiten describir adecuadamente la estructura genética de la Argentina y coinciden con las particularidades de su poblamiento.Asociación de Antropología Biológica de la República Argentin

What’s in a surname? Physique, aptitude, and sports type comparisons between Tailors and Smiths

Combined heredity of surnames and physique, coupled with past marriage patterns and trade-specific physical aptitude and selection factors, may have led to differential assortment of bodily characteristics among present-day men with specific trade-reflecting surnames (Tailor vs. Smith). Two studies reported here were partially consistent with this genetic-social hypothesis, first proposed by Bäumler (1980). Study 1 (N = 224) indicated significantly higher self-rated physical aptitude for prototypically strength-related activities (professions, sports, hobbies) in a random sample of Smiths. The counterpart effect (higher aptitude for dexterity-related activities among Tailors) was directionally correct, but not significant, and Tailor-Smith differences in basic physique variables were not significant. Study 2 examined two large datasets (Austria/Germany combined, and UK: N = 7001 and 20532) of men’s national high-score lists for track-and-field events requiring different physiques. In both datasets, proportions of Smiths significantly increased from light-stature over medium-stature to heavy-stature sports categories. The predicted counterpart effect (decreasing prevalences of Tailors along these categories) was not supported. Related prior findings, implicit egotism as an alternative interpretation of the evidence, and directions for further inquiry are discussed in conclusion

Twin Town in South Brazil: A Nazi's Experiment or a Genetic Founder Effect?

Cândido Godói (CG) is a small municipality in South Brazil with approximately 6,000 inhabitants. It is known as the “Twins' Town” due to its high rate of twin births. Recently it was claimed that such high frequency of twinning would be connected to experiments performed by the German Nazi doctor Joseph Mengele. It is known, however, that this town was founded by a small number of families and therefore a genetic founder effect may represent an alternatively explanation for the high twinning prevalence in CG. In this study, we tested specific predictions of the “Nazi's experiment” and of the “founder effect” hypotheses. We surveyed a total of 6,262 baptism records from 1959–2008 in CG catholic churches, and identified 91 twin pairs and one triplet. Contrary to the “Nazi's experiment hypothesis”, there is no spurt in twinning between the years (1964–1968) when Mengele allegedly was in CG (P = 0.482). Moreover, there is no temporal trend for a declining rate of twinning since the 1960s (P = 0.351), and no difference in twinning among CG districts considering two different periods: 1927–1958 and 1959–2008 (P = 0.638). On the other hand, the “founder effect hypothesis” is supported by an isonymy analysis that shows that women who gave birth to twins have a higher inbreeding coefficient when compared to women who never had twins (0.0148, 0.0081, respectively, P = 0.019). In summary, our results show no evidence for the “Nazi's experiment hypothesis” and strongly suggest that the “founder effect hypothesis” is a much more likely alternative for explaining the high prevalence of twinning in CG. If this hypothesis is correct, then this community represents a valuable population where genetic factors linked to twinning may be identified

The significance of nitrogen cost minimization in proteomes of marine microorganisms

Marine microorganisms thrive under low levels of nitrogen (N). N cost minimization is a major selective pressure imprinted on open-ocean microorganism genomes. Here we show that amino-acid sequences from the open ocean are reduced in N, but increased in average mass compared with coastal-ocean microorganisms. Nutrient limitation exerts significant pressure on organisms supporting the trade-off between N cost minimization and increased average mass of amino acids that is a function of increased A+T codon usage. N cost minimization, especially of highly expressed proteins, reduces the total cellular N budget by 2.7–10% this minimization in combination with reduction in genome size and cell size is an evolutionary adaptation to nutrient limitation. The biogeochemical and evolutionary precedent for these findings suggests that N limitation is a stronger selective force in the ocean than biosynthetic costs and is an important evolutionary strategy in resource-limited ecosystems