The Toba "supereruption" is first off, a way for volcanologists to stay in the game -- they were blindsided and thrown out the front door by the bouncers when the Alvarez model took hold. Dewey Mclean (may he rest in peace) got dragged along out of his uniformitarian gradualist fantasyland, became the de facto leader of the opposition to the insurgent theory, and eventually wound up in a downward spiral, blaming Luis Alvarez for the sudden decline of his previously obscure career. Alvarez probably tried to give him some friendlly advice in private, that hey, Dewey, you're making yourself look bad, which Dewey then publically branded a threat. He found out that there was a level of discontent among others in his department and at the university at his overall performance.
The second thing the Toba "supereruption" did was try to plug a few holes in the Out-of-Africa/Replacement Model, which is the quintessential master race model of the modern sciences. Our various ancestors spent much of the past two million years emerging from whatever came before, and that time was mostly spent on the now-submerged continental shelf, as what we now regard as the Earth was ice-covered. Use of watercraft is at least 800,000 years old, so they got around without much impediment. /pedantic off
That is a very startling claim.
Were they constructed and used by Homo Erectus?
Are there real artifacts to confirm this?
Thanks for clarifying.