A "Corridor for bidirectional migrations between East Africa and North East Africa" is proposed as a result of the paper's findings:
"E-M78 belongs to clade E3b (E-M215). On the basis of robust phylogeographic considerations, an eastern African origin has been proposed for E-M215 (Underhill et al. 2001; Cruciani et al. 2004), with a coalescence time of 22.4 ky (95% C.I. 20.9-23.9 ky; recalculated from Cruciani et al. 2004, see Materials and Methods). A north-eastern African origin for haplogroup E-M78 implies that E-M215 chromosomes were introduced in north-eastern Africa from eastern Africa in the Upper Paleolithic, between 23.9 ky ago (the upper bound for E-M215 TMRCA in eastern Africa) and 17.3 ky ago (the lower bound for E-M78 TMRCA here estimated, fig. 1). In turn, the presence of EM78 chromosomes in eastern Africa can be only explained through a back migration of chromosomes that had acquired the M78 mutation in north-eastern Africa."
1) E1b1b1a (E-M78) frequencies in East African populations.
(Taken from Fig. 3)
Microsatellite networks of haplogroups E-V12 (A); E-V22 (B); and E-V65 (C). In network (A), a dotted circle includes all of the E-V12 chromosomes carrying the V32 mutation. Branch lengths are proportional to the number of one-repeat mutations separating 2 haplotypes. Each circle area is proportional to the frequency of the sampled haplotype.
4) Comparing Cruciani '07 results to the E3b Project.
Notice on the comparison of the results of Cruciani '04 to the E3b project that there is an imbalance of E-M78 lineages (in favor of the E3b Project), above we can see that this imbalance is further characterized by the marked abundance of E-V13 lineages in the E3b Project, this makes sense because E-V13 is for the most part found only in Europe, and Europeans have better financial and technological access to participate in private DNA testing.
5) Further reading and sources on E-M78.
Hassan et. al 2008:"Y-Chromosome Variation Among Sundanese: Restricted Gene Flow, Concordance with Language, Geography, and History"
Sanchez et. al 2005:"High Frequencies of Y Chromosome Lineages Characterized by E3B1, DYS19-11, DYS392=12 in Somali Males"
Battaglia et al. 2008:
"Y-chromosomal evidence of the cultural diffusion of agriculture in southeast Europe"