The genetic bottleneck around the time of the eruption was not as “near” as all that—in part since there were Neanderthals around at that time as an additional backup mechanism, complementing the surviving humans. Plus, of course, Homo floresiensis! ;-)
Figures from before the eruption appear to have not been dramatically higher:
Scientists from the University of Utah in Salt Lake City in the U.S. have calculated that 1.2 million years ago, at a time when our ancestors were spreading through Africa, Europe and Asia, there were probably only around 18,500 individuals capable of breeding (and no more than 26,000).
True. I had forgotten the genetic bottleneck. Also I think I conflated the risks that will increase with technology (Nukes, Bio, Totalitarian) with the risks that were the actual closest near misses—the anthropic principle doesn’t care.
The proposed genetic bottleneck around the time of the eruption was long ago—when the human population may have been very small anyway. Today, we have six billion humans. There are better defenses against such things—in terms of stocked underground bunkers. So: a modern volcanic eruption would have to be vastly more destructive to kill all humans. The probabilities involved are miniscule, and shrink with every passing day. It is only because of a “Pascal’s wager”-style argument that people can be made to consider such risks.
Toba supereruption and genetic bottleneck probably strongest example of near-miss.
The genetic bottleneck around the time of the eruption was not as “near” as all that—in part since there were Neanderthals around at that time as an additional backup mechanism, complementing the surviving humans. Plus, of course, Homo floresiensis! ;-)
http://en.wikipedia.org/wiki/Toba_catastrophe_theory estimates we got down to the last 5,000-10,000 backup copies of the human genome.
Figures from before the eruption appear to have not been dramatically higher:
http://www.physorg.com/news183278038.html
There just weren’t that many homos around at the time.
True. I had forgotten the genetic bottleneck. Also I think I conflated the risks that will increase with technology (Nukes, Bio, Totalitarian) with the risks that were the actual closest near misses—the anthropic principle doesn’t care.
The proposed genetic bottleneck around the time of the eruption was long ago—when the human population may have been very small anyway. Today, we have six billion humans. There are better defenses against such things—in terms of stocked underground bunkers. So: a modern volcanic eruption would have to be vastly more destructive to kill all humans. The probabilities involved are miniscule, and shrink with every passing day. It is only because of a “Pascal’s wager”-style argument that people can be made to consider such risks.