Possible Demise of the Neanderthals?...

[Rockhopper]

Apparently Toba Volcano in Sumatra erupted about 70,000 years ago and plunged the world into a volcanic winter that last for around 10 years. Plants died and with them many animals. Our Sapiens ancestors were decimated too although they were in Africa at that time. Europe was plunged into a deep Ice Age that spread around the world after the eruption. That could have been the reason the Neaderthals disappeared. The remaining few that did survive were assimilated into us.

The Toba super-volcano has erupted explosively a number of times over the past 1.2 million years. By far the largest and most destructive of these occurred around 74,000 years ago, and it is this ‘Youngest Toba Tuff’ or YTT eruption that forms the focus of this research project. At least 2800 cubic kilometres of volcanic material was ejected during this super-eruption, dwarfing historical eruptions such as Krakatoa and Pinatubo.

The YTT explosion instantly destroyed all life in its immediate area, with intensely hot flows comprised of billions of tonnes of ash and rock, accompanied by a deafening noise and powerful tsunamis. It also sent hundreds of cubic kilometers of ash and gases high into the atmosphere, even as the volcano itself collapsed inwards to form a huge sunken caldera (now Lake Toba). The gases, including sulfur, circled the globe on air currents, while the ash spread out to the north and west fanned by prevailing winds. When the ash began to fall, it covered the Indian subcontinent and rained down into oceans from the Arabian Sea in the west to the South China Sea in the east (the figure above shows all the locations from which YTT desposits have been recovered to date). Gradually the earth cooled as the sun’s heat was reflected by the suspended gases, affecting rainfall and climates across the globe. Around this time the earth slipped rapidly into a dramatically cold portion of the ice ages, and while this was underway before Toba’s eruption, the super-volcano undoubtedly had an important influence.

From Here.

Tim.

[Kaere]

I hadn't heard this theory before but truth be told, it seems (to me) to be the most plausible. Thanks for posting

[Rogue]

Yes, and historically other Volcanic events have also played out their roles on our planet in various ways. Sorry to quote Wiki but it is interesting..

Historic examples

Pinatubo early eruption, 1991
The effects of volcanic eruptions on recent winters are modest in scale, but historically have been significant.

Most recently, the 1991 explosion of Mount Pinatubo, a stratovolcano in the Philippines, cooled global temperatures for about 2–3 years.[2]

In 1883, the explosion of Krakatoa (Krakatau) created volcanic winter-like conditions. The four years following the explosion were unusually cold, and the winter of 1887-1888 included powerful blizzards.[3] Record snowfalls were recorded worldwide.

The 1815 eruption of Mount Tambora, a stratovolcano in Indonesia, occasioned mid-summer frosts in New York State and June snowfalls in New England and Newfoundland and Labrador in what came to be known as the "Year Without a Summer" of 1816.

A paper written by Benjamin Franklin in 1783[4] blamed the unusually cool summer of 1783 on volcanic dust coming from Iceland, where the eruption of Laki volcano had released enormous amounts of sulfur dioxide, resulting in the death of much of the island's livestock and a catastrophic famine which killed a quarter of the Icelandic population. Northern hemisphere temperatures dropped by about 1 °C in the year following the Laki eruption.

In 1600, the Huaynaputina in Peru erupted. Tree ring studies show that 1601 was cold. Russia had its worst famine in 1601-1603. From 1600 to 1602, Switzerland, Latvia and Estonia had exceptionally cold winters. The wine harvest was late in 1601 in France, and in Peru and Germany, wine production collapsed. Peach trees bloomed late in China, and Lake Suwa in Japan froze early.[5]

In 1452 or 1453, a cataclysmic eruption of the submarine volcano Kuwae caused worldwide disruptions.

The Great Famine of 1315–1317 in Europe may have been precipitated by a volcanic event,[6] perhaps that of Mount Tarawera, New Zealand, lasting about five years.[7]

The extreme weather events of 535–536 are most likely linked to a volcanic eruption. The latest theorised explanation is the Tierra Blanca Joven (TBJ) eruption of the Ilopango caldera in central El Salvador.[8]

One proposed volcanic winter occurred around 73,000–71,000 years ago following the supereruption of Lake Toba on Sumatra island in Indonesia. In the following 6 years there was the highest amount of volcanic sulphur deposited in the last 110,000 years, possibly causing significant deforestation in Southeast Asia and the cooling of global temperatures by 1 °C.[9] Some scientists hypothesize that the eruption caused an immediate return to a glacial climate by accelerating an ongoing continental glaciation, causing massive population reduction among animals and human beings. Others argue that the climatic effects of the eruption were too weak and brief to impact early human populations to the degree proposed.[9]

This, combined with the abrupt occurrence of most human differentiations in that same period, is a probable case of bottleneck linked to volcanic winters (see Toba catastrophe theory). On average, super-eruptions with total eruptive masses of at least 1015 kg (Toba eruptive mass = 6.9 × 1015 kg) occur every 1 million years.[10]

However, archaeologists who in 2013 found a microscopic layer of glassy volcanic ash in sediments of Lake Malawi, and definitively linked the ash to the 75,000-year-old Toba super-eruption, went on to note a complete absence of finding the change in fossil type close to the ash layer that would be expected following a severe volcanic winter. This result led the archaeologists to conclude that the largest known volcanic eruption in the history of the human species did not significantly alter the climate of East Africa.

http://en.wikipedia.org/wiki/Volcanic_winter

Effects on life

The supervolcano Caldera Lake Toba
The causes of the population bottleneck— a sharp decrease in a species' population, immediately followed by a period of great genetic divergence (differentiation) among survivors—is attributed to volcanic winters by some researchers. According to anthropologist Stanley Ambrose, such events diminish populations to "levels low enough for evolutionary changes, which occur much faster in small populations, to produce rapid population differentiation". With the Toba bottleneck, many species show massive effects of narrowing of the gene pool, and it is believed Toba nearly exterminated humankind.

Link as above.

[Kaere]

Fascinating, thanks Rogue

[Agartha]

Very interesting theory!! However, even if the Neanderthal population was reduced, fossil record shows that many still lived....... until we arrived.....

[Rockhopper]

Yep Ags. They were probably assimilated into Sapiens. We all carry Neanderthal genes.

Wiki is good for just general info but not so good for accurate stuff. Your quotes Rogue, show how we know what the climate has done over the centuries. Ice cores tell us about things that happened 100,000's of years ago.

There were apparently little clusters of Humans that survived the eruptions in various places: India, Spain, Africa and Indonesia (Flores). I suppose that they all mixed in and we are the result.

Tim.

[Rogue]

Apologies for quoting wiki, but I thought I had already said that.

[Rockhopper]

You did and apologies accepted!

Seriously, there have been many extinction events throughout history.

Tim.

[Rogue]

Of course there have and they will continue to happen.

[Rockhopper]

We are our own worst enemies Rugue.

Tim.

[Rogue]

Yes we are, but we can't have any control over events like volcanic eruptions. We are insignificant when it comes to nature.

[Kaere]

Watching/listening to this right now...

[Agartha]

Man, all these amazing documentaries that I can't watch yet!!!!

[Kaere]

Well, to be fair... you can skip through a lot of that one and still get the gist of it

[Agartha]

Oh no, documentaries have to watched properly!!
lol

[Rockhopper]

Download 'em and then watch at your leisure Ags!

Tim.

[Agartha]

I know, but it's lack of proper 'nothing else to do' time that I don't have right now.....

But I will watch them eventually......

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