Recent studies on the common J1 Y chromosome suggest it arrived over ten thousand years ago in North Africa, and M81/E3b2 is a Y chromosome specific to North African ancestry, dating to the Neolithic. A thorough study by Arredi et al. (2004) which analyzed populations from Algeria concludes that the North African pattern of Y-chromosomal variation (including both E3b2 and J haplogroups is largely of Neolithic origin, which suggests that the Neolithic transition in this part of the world was accompanied by demic diffusion of Afro-Asiatic–speaking pastoralists from the Middle East. This Neolithic origin was later confirmed by Myles et al. (2005) which suggest that "contemporary Berber populations possess the genetic signature of a past migration of pastoralists from the Middle East",