Oppenheimer says they reached south asia at 60kya. Then they migrated from South Asia to Europe 40 to 25 kya. So another westward migration is entirely plausible.
Human migrations out of Africa, Stephen Oppenheimer
dnalc.cshl.edu
Essentially there are only two or perhaps three routes out of Africa. One is across the mouth of the Red Sea, the other is across the Suez, and the third is across the Straits of Gibraltar. And really there's very little evidence that the original modern human migration went across Gibraltar, although other migrations certainly did. And so it's a choice of two, between the mouth of the Red Sea and the Suez. And to determine which route was taken, we really have to look at the descendant lineages, or descendant haplogroups or genetic lines, which are on the other side of that gate. And if we look in southern Arabia in India, we find all of the early branches of M and N [two human lineages] in great profusion. If on the other hand, we look in the Near East, all we find is N. And not only do we only find N, we only find highly derived groups of N, which are characteristic of Europeans and Near Easterners. And so the diversity of lineages that are found outside the gate, northern gate, are very much less than the diversity of lineages which are found to the east of the southern gate.
African mitochondrial DNA tree, Stephen Oppenheimer
dnalc.cshl.edu
Interviewee: Stephen Oppenheimer. Geneticist Stephen Oppenheimer talks about the mitochondrial DNA and Y chromosome lineages of our ancestors. (DNAi Location: Applications > Human origins> Migrations> Videos > Paths out of Africa)
There's only one branch of the African mitochondrial DNA tree, that's called L3 [a human lineage], which is related to all non-African populations. And it appears that L3, split into two outside Africa, around 80,000 years ago, and these two branches have been called M and N, and if you look at all well populations, you'll find either one or both of these, in fact in European populations there's only N, and in all other non-African populations there are both M and N descendants. In the case of the Y chromosome, there's one mutation, M168, which was discovered in Peter Underhill's laboratory, and M168 again, accounts for all non-African populations.
