Humans in Asia survived Toba super-eruption 74,000 years ago

Chris Clarkson and company have produced a study arguing that the super volcano Toba eruption of 74,000 years ago did not lead to a population bottleneck in Asia, as has been suggested.  Brook Hays of UPI writes:

For the study, scientists analyzed evidence of human populations and climate change across a significant stratigraphic record -- a column of rock and sediment layers comprising 80,000 years of history -- from the Dhaba dig site in northern India's Middle Son Valley.

The column yielded stone artifacts suggesting Middle Palaeolithic tool-using populations were present in India prior to the Toba eruption.

"Although Toba ash was first identified in the Son Valley back in the 1980s, until now we did not have associated archaeological evidence, so the Dhaba site fills in a major chronological gap," researcher J.N. Pal, professor of ancient history and archaeology at the University of Allahabad in India, said in a news release.

The authors argue that there are stone tools at the Dhaba site the strongly resemble Middle Stone Age tools in Northeast Africa. The occupation levels go down to 48,000 years ago, where Levallois and microlithic tools are found. This suggests continuous occupation of the site by different groups with similar stone tool technologies.

Time to chuck another theory into the dustbin of history.  

Neandertal to Modern Transition Full of Fits and Spurts

New evidence suggests that Neandertals survived longer on the Iberian peninsula than elsewhere in Europe.  The redating of the Zafarraya Neandertal from the late 20k's to between 38 and 40 ky saw a revision of theories about Neandertal extinction. Now more evidence has been unearthed suggesting that this window is more secure.   From The Statesman:

Neanderthals may have survived at least 3,000 years longer than thought in what is now Spain – much after the species had died out everywhere else, a study has found.

The findings suggest that the process of modern human populations absorbing Neanderthal populations through interbreeding was not a regular, gradual wave-of-advance but a “stop-and-go, punctuated, geographically uneven history.”

Over more than ten years of fieldwork, researchers excavated three new sites in southern Spain, where they discovered evidence of distinctly Neanderthal materials dating until 37,000 years ago.

“Technology from the Middle Paleolithic in Europe is exclusively associated with the Neanderthals,” said Joao Zilhao, from the University of Barcelona in Spain.

“In three new excavation sites, we found Neanderthal artefacts dated to thousands of years later than anywhere else in Western Europe,” said Zilhao, lead author of the study published in the journal Heliyon.

It seems pretty clear now that the model of rapid replacement of Neandertals does not hold. This kind of evidence, along with sites such as Lagar Velho, suggest that the transition, at least in this region was long-term, with much hybridization.  We still do not know exactly how long Neandertals persisted in this region.  It makes perfect sense that they would have been the last ones to undergo the transition (however that happened) because the earliest Aurignacian sites, associated with modern humans, occur in far eastern Europe as the wave of moderns came through during the Würm I/Würm II interglacial.

The question that I have is why didn't the earliest modern humans, represented by the Jebel Irhoud remains, come through the Strait of Gibraltar?  North of that, all you find are archaic, all the way down to the Zafarraya remains.  I wonder why this is.