Biggest earthquake in 40 years hits Southeast Asia - Part 2

[Ned]

John T, the problem with your measure is that the casualties took place over years. The question should be, what event in history cost the most human life in one day.

[JohnT]

T'wasn't my measure ( ), and I only posted that in reply to Che's assertion of a million killed in Verdun and not as part of the larger discussion.

[Bosh]

Originally posted by Ned
John T, the problem with your measure is that the casualties took place over years. The question should be, what event in history cost the most human life in one day.

Well as far as %'s go there was a volcanic eruption way way back in the Stone Age that killed off easily the majority of the human population (from mitochondrial DNA analysis its believed that we are all descended from only a handful of females who survived it and were able to reporduce.

[Ned]

Bosko, handful? In the whole world?

[chequita guevara]

Bosko's a drink.

[chequita guevara]

Originally posted by Ned
Bosko, handful? In the whole world?

The volcano Krakatoa explodes with disturbing regularity, about every 150 years. With some of it's more massive explosions, it's put enough particiluate matter into the atmosphere to lower temperatures globally. An eruption in 550AD is believed to be responsible for the fall of Justinian's Empire, as well as the Olmec and others, and caused famine througout much of the world.

There is evidence of a catastrophic volcanic eruption that basically caused a global winter.

[Bosh]

Originally posted by chegitz guevara
Bosko's a drink.

Wha?????


Ned: Look here http://www.andaman.org/book/app-r/ch...eck/textr5.htm

It was the Toba volcano about 75,000 I believe, at least that's what my ecology prof told me in college.

[chequita guevara]

Originally posted by Boshko

Wha?????

You've never heard of Bosko? Can't seem to find it on google, but I seem to remember a canned drink called Bosko that was like Yoohoo.

[Bosh]

Originally posted by chegitz guevara


You've never heard of Bosko? Can't seem to find it on google, but I seem to remember a canned drink called Bosko that was like Yoohoo.

Never heard of it. I thought Bosko was a cartoon character.

[Jon Miller]

I haven't done anything for these peoplse yet

but they have been in my prayers

I don't really know what the best way to help is, and didn't really have money until a copule of days ago

Jon Miller
(was jobless for a bit)

[Ned]

Bosko, thanks for the link. Fascinating that Hobbits lived on Flores at late as 12,000 years ago; and may still live there even today.

As to the thesis that humans were reduced to a handful by Toba, thus explaining our lack of genetic diversity, there is another possibility is there not?

[Bosh]

Originally posted by Ned
Bosko, thanks for the link. Fascinating that Hobbits lived on Flores at late as 12,000 years ago; and may still live there even today.

As to the thesis that humans were reduced to a handful by Toba, thus explaining our lack of genetic diversity, there is another possibility is there not?

There are other explanations, but Toba's the best. It was a really really really big-ass volcano. Also before Toba we find some homo sapiens outside of Africa (mid-east area generally) and then no evidence of homo sapien remains outside of Africa for quite a bit after that (again, according to my old ecology prof).

Also, by looking at mitochondrial DNA we can make a pretty good guess as to when the bottleneck occored and it lines up pretty well to the Toba eruption.

[Ned]

Question: when a new species evolves, its genetic makup has to be somewhat limited, not so? It is not clear to me that our own lack of genetic diversity vis-a-vis the chimps, for example, is not because we are a realtively new species compared to them even though the chart on the link suggests that chimps are a newer species than humans.

Still, it is interesting that the volcanic eruption of Toba brought on a new ice age. If there was a mass extinction of humans at that time, I think it had to occur in the immediate years after the erruption caused by sever cold. The chart indicates that the population collapse occured over thousands of years. I find that to be unlikely.

[Bosh]

Originally posted by Ned
Question: when a new species evolves, its genetic makup has to be somewhat limited, not so? It is not clear to me that our own lack of genetic diversity vis-a-vis the chimps, for example, is not because we are a realtively new species compared to them even though the chart on the link suggests that chimps are a newer species than humans.

Still, it is interesting that the volcanic eruption of Toba brought on a new ice age. If there was a mass extinction of humans at that time, I think it had to occur in the immediate years after the erruption caused by sever cold. The chart indicates that the population collapse occured over thousands of years. I find that to be unlikely.

Again, the paraphrase my old ecology prof, the level of genetic diversity (especially mitochondrial which is only passed on from the mother and mutates at a pretty predictable rate) is low enough to suggest a pretty big bottle-neck at around the time of the Toba eruption. It is not at all consistent with the existance of a relatively large human population all the way back to the older homo sapien remains that we have.

Also the chart you're looking at is just a schematic, we obviously don't when and how fast the human population dropped to cause the bottleneck. Again, all we basically know is:

A. Before the toba eruption there were human populations in the mid-east area and after the toba eruption is seems that humans were knocked back to Africa.

B. Due to the diversity of human mitochondrial DNA it was probable that the human population bottlenecked hard at around the time of the toba eruption. Other scenarios are possible, such as a longer and more gentle bottleneck, but having the toba eruption and the subsequent ice age resulting in a bottle neck in the human population seems the most probable.

C. The toba eruption was very very very big.

[Ned]

What I find shocking, as well, is that Toba is so very, very close to the recent 9.0 earthquake that caused the massive tidal wave. Gives one pause. Could this earthquake portend another massive volcanic event in that area?

Back to DNA. Is there a way to calculate the timing of the so-called bottleneck by some other form of analysis that looks only to the human genome? For example, if we know humans arrived in Australia 50,000 years ago, we can measure the genetic diversity of Australian natives and determine, roughly, the rate of diversification of a population. We can then take the African population and calculate the date of the origin of our species using the Australian metric.