Españoles en los mapas genéticos

En estos mapas genéticos se puede visualizar la similud genétcia de entre varias poblaciones  (cuanto más cerca aparecen dos poblaciones en el mapa, más cercanas genéticamente).

Los españoles (del sur o del norte) aparecemos entre Franceses e Italianos del Norte (de Lombardia), algo que se asemeja a nuestra posición geográfica, sin embargo los norte-africanos quedan muy lejanos a nosotros, más emparentados estos últimos con poblaciones del medio-oriente.

Otras poblaciones del mediterráneo, como Italianos del Sur, Sicilianos y algunos Griegos, quedan algo lejanos a nosotros, de hecho hay aproximadamente la misma distancia genética entre ellos y nosotros, que la que hay entre poblaciones del Noroeste de Europa con nosotros.

Hacer click en la imágenes para agrandar :

Sub-Saharan admixture in the Mediterranean basin

González-Pérez et al. (2010) have analyzed populations from the northern and southern shores of the Mediterranean, with Central Europeans and West Africans as external references. In the Discussion section, they admit that the inflated "Alu/STR estimate might be artefactual" and favor the estimate based on the Alu  loci set alone because it's consistent with previous mtDNA, Y-chromosome and 500,000-SNP structure data.
According to the more accurate latter method, Sub-Saharan African admixture is ~13% in North Africa and "imperceptible" or noise (~ 0.01%) in Southern Europe:

ADMIXTURE up to K=20 (Rasmussen et al. 2011)

The recently published paper by Rasmussen et al. is focused on the Aboriginal Australians, and inlcudes a massive ADMIXTURE analysis up to 20 ancestral components (K=20). The Spaniard sample (taken from Behar et al.) in this run is similar-looking to other Western-European populations, showing the dark-blue component (peaks in Lithuanians) at similar levels as the French, and the whiteish-blue component (peaks in Sardinians).

The original size can be found in the supplementary PDF here (page 159) :

Spaniards genetically similar to Western and Northern Europeans

Study from Gayán et al. 2010 , some extracts :
 
In this study we have sampled over 800 unrelated individuals from the population of Spain, and have genotyped them with a genome-wide coverage. We have carried out linkage disequilibrium, haplotype, population structure and copy-number variation (CNV) analyses, and have compared these estimates of the Spanish population with existing data from similar efforts. Conclusions: In general, the Spanish population is similar to the Western and Northern Europeans but has a more diverse haplotypic structure. These results suggest that the general Spanish population, as characterized in the present study by sampling from eight different cities widely-spaced across Spain, is generally similar to other European populations, although more genetically diverse than Western and Northern Europeans. Moreover, the Spanish population is remarkably homogeneous within itself in terms of global genetic structure. In view of these results, the population of Spain is sufficiently genetically similar to the CEU sample (White-Americans from Utah) so that the CEU HapMap dataset could be used to infer genotypes for the Spanish population.