An average Caucasian hair is right at 100 microns in diameter. The hair of all other races are larger.
Now, Toba is a neat story and one fun to reckon with.
I've had my own doubts too when I first read about the Hobbits on Flores Island (very near to Toba) and their dating to 80,000+ years. They would have had to survive the Toba eruption too...so...
Prevailing winds being what they are, the Toba ask would probably have moved toward the east, and landed on Africa after much dispersion. Nevertheless, I am sure that world hominid populations took a significant hit after Toba, although probably less in parts of Africa. I have noticed that while there were a number of finds dated before that period, there was something of a gap until 10 to 20,000 years after Toba.
Temperature charts show a significant drop after Toba in a downward slope that is already noticeable. That being the case, Flores would have been larger because sea water levels would have been lower than today and grown as temperatures continued to drop. If they exploited seafood resources both animal and vegetable, they would not have starved, even if land resources had taken a significant hit.
For another interesting survival story, check out the Kow hominids in Australia. Apparently they were killed off around 12,000 years ago. In the Koch brothers exhibit of skulls and what they show about evolution, a Kow skull is identified as Homo Sapien. It is at the far right of the exhibit wall and in the lower area. However after looking at it very carefully, it seemed to me to have more Heidelbergensis characteristics than either Homo or Neanderthal. This could mean that these hominids arrived in Australia several ice age cycles ago when water was low, but were killed off by the arrival of the current native Australians who arrived around 40,000 years ago.
Here is a link with a long article about the Kow Swamp Homo argument. It even mentions the possibility of a Heidelberg or late Solo relationship.
Here is another find of non modern Australians. http://austhrutime.com/wlh-50.htm
Having read several other articles about this it seems that archaeologists in Australia are having the same problem with wanting to look at new data as we have seen in US regarding the “nothing before Clovis” mind set, or the failure to search under water for ice age shoreline cultural remnants.
Flores Island combines well with the current idea that the Bottlenecks were, in fact, the effects of relatively large migrations out of Africa. I’ve read that also that human tool kits have been found in India immediately on top of the Toba ash.
I’m sure something else will soon come along to again turn things upside down.
That stuff would still be coming back
Should still be detectable.