Prehistoric contacts over the Straits of Gibraltar indicated by genetic analysis of Iberian Bronze Age cattle

Abstract

The geographic situation of the Iberian Peninsula makes it a natural link between Europe and North Africa. However, it is a matter of debate to what extent African influences via the Straits Gibraltar have affected Iberia's prehistoric development. Because early African pastoralist communities were dedicated to cattle breeding, a possible means to detect prehistoric African-Iberian contacts might be to analyze the origin of cattle breeds on the Iberian Peninsula. Some contemporary Iberian cattle breeds show a mtDNA haplotype, T1, that is characteristic to African breeds, generally explained as being the result of the Muslim expansion of the 8th century A.D., and of modern imports. To test a possible earlier African influence, we analyzed mtDNA of Bronze Age cattle from the Portalón cave at the Atapuerca site in northern Spain. Although the majority of samples showed the haplotype T3 that dominates among European breeds of today, the T1 haplotype was found in one specimen radiocarbon dated 1800 calibrated years B.C. Accepting T1 as being of African origin, this result indicates prehistoric African-Iberian contacts and lends support to archaeological finds linking early African and Iberian cultures. We also found a wild ox haplotype in the Iberian Bronze Age sample, reflecting local hybridization or backcrossing or that aurochs were hunted by these farming cultures.

Fig. 1.

Map shows sites sampled in this study. 1, Portalón cave of the Atapuerca site and the medieval site of San Pablo Burgos, both in Spain; 2, Valparasio de Abajo, Cuenca, Spain; 3, Cueva de Joaquin, Teruel, Spain; 4, Cueva Mosset, Mallorca, Escorca, Spain; 5, the Central European sites of Zauschwitz and Werben, both in Germany.

Fig. 2.

Reduced median network [Network 4.109 (30); threshold set for 2] of 313 sequences downloaded from GenBank and 30 ancient Bos sequences presented in this study. Six haplogroups, T, T1, T2, T3, the Asian haplogroup T4 (38), and the primigenius haplogroup, are labeled. The position for the ancient sequences presented here that do not fall within the center of the T3 cluster are also labeled. The ancient sequences in the T3 cluster, marked with an asterisk, are MAD2, MAD3, MAD5, MAD6, MAD8, MAD11, MAD14, MAD17, MAD18, MAD20, MAD23, MAD45, MAD46, MAD49, MAD50, DD24, DD25, DD27, DD29, DD36, DD83, and DD85.