Posts
There is an interesting article at Science Daily today that adds important information for one of the discussions that have arisen in Leherensuge recently: did humans caused megafauna extinctions?
The answer is clearly no. Not directly at least. Woolly mammoths are known to have existed in the Iberian peninsula, specially but not only in the North, not just in the Neanderthal (Middle Paleolithic) period but specially in the Upper Paleolithic period, when modern humans were already established and thriving in the region.
These species lived alongside different human cultures. There is evidence in some sites of the Basque country, Navarra and Catalonia that the Neanderthals coexisted with the mammoths and the reindeer at specific times. However, the majority of evidence of these faunae coincides with the periods of the Gravettian, Solutrean and Magdalenian cultures.
The most important detail for me is the word Magdalenian. We know with some certainty that population grew quickly in the Magdalenian period, after the Last Glacial Maximum, yet megafauna was still there and seems rather abundant.
The key element for the vanishing of these large herbivores in Iberia was the end of the Ice Age, when forests became the dominant feature of a warmed up landscape in which these animals, adapted to cold and steppe, could not survive.
There is however an ill-understood gap in the 31-26 Ka period (Aurignacian period, which in Iberia lasts from c. 30 Ka to c. 22 Ka. BP uncalibrated), when the megafauna findings are lacking.
Ref. Diego J. Álvarez-Lao and Nuria García, Chronological distribution of Pleistocene cold-adapted large mammal faunas in the Iberian Peninsula. Quaternary International, 2010. Pay per view.
23 comments:
"The answer is clearly no".
Not so fast Maju. From the link:
"Some species such as the reindeer and the arctic fox found their new habitat in the arctic regions of the planet, where they still survive today. Others, such as the woolly mammoth and the woolly rhinoceros weren't so lucky"
Why did just those two species die out?
"These species lived alongside different human cultures"
We've known that for years.
"The most important detail for me is the word Magdalenian. We know with some certainty that population grew quickly in the Magdalenian period, after the Last Glacial Maximum, yet megafauna was still there and seems rather abundant".
But (coincidently?) That's when the megafauna died out.
"According to the team, the last findings of these cold species date back some 10,000 years"
The authors don't actually specify that woolly mammoths and rhinos survived until that time, but let's suppose they did. We already know that the two species lasted in southern France longer than they had further east. So, presumably, the mammoths in the region were able to replenish their numbers from outside the region. Probably from somewhere to the north or east that humans had been unable to colonise before about 12,000 years ago.
"Why did just those two species die out?"
I think that largely because they were bigger, needed more resources and could support lesser numbers.
"We've known that for years".
You're saying all the time that when humans arrive anywhere the first thing they do is to massacre all the fauna that has some size or something, specially elephants.
It is not that way at all.
"But (coincidently?) That's when the megafauna died out".
The article says that "the last findings of these cold species date back some 10,000 years, and coincide with the end of the glaciations". This is the beginning of Epipaleolithic (Azilian, etc.) and the end of the Ice Age. It heralded radical changes all around but the driving force was climatic, nothing that humans could affect at their numbers and technological level.
"We already know that the two species lasted in southern France longer than they had further east. So, presumably, the mammoths in the region were able to replenish their numbers from outside the region. Probably from somewhere to the north or east that humans had been unable to colonise before about 12,000 years ago".
That's twisting the facts beyond recognition. We just do not know that much. But if they lasted longer in all the Franco-Cantabrian Region, precisely the area with densest human occupation of all Europe, it seems to me that it's fair to conclude that humans and mammoths lived side by side all the time without bothering.
Anyhow, Paleolithic meals are mostly deer, horse, goat and bovid. I even know of tools made of whale barb and other evidence of sea mammals being exploited in Magdalenian times but I can't recall anywhere reading, Homo sapiens here or there were specialized in hunting mammoths or ate a lot of mammoth. Maybe in Eastern Europe, where mammoth bones were at times used instead of the scarce wood for hut construction, but not in the SW.
"That's twisting the facts beyond recognition. We just do not know that much".
Is that really so? But many of us know quite a bit about ecology, and know that species can easily move from regions where they are not hunted into regions where they are. This is why many countries are so keen to establish no-fishing reserves for example. It's is much more than just 'possible' that something similar was at work in the megafauna extinctions, although I doubt that any 'no-take reserve' was human directed. just that they were unable to access it with the technology they possessed.
"I think that largely because they were bigger, needed more resources and could support lesser numbers".
That argument doesn't actually stack up at all as the reason for the extinction. It is probably relevant as a factor increasing the likelihood of human-induced extinction though.
"You're saying all the time that when humans arrive anywhere the first thing they do is to massacre all the fauna that has some size or something, specially elephants".
You love making things up to suit your purpose. I'm sure I've even used the term 'saturation point' for when the human population was sufficient to cause extinctions.
"It heralded radical changes all around but the driving force was climatic, nothing that humans could affect at their numbers and technological level".
I'm sure you will not take this seriously because it conflicts with your belief, and it's quite old now. It's from July this year.
http://www.reuters.com/article/idUSTRE66E17R20100715
I presume you won't even read these extracts let alone the whole article. But, from the article:
"The end of the last Ice Age, marked by a worldwide rise in temperatures and the dramatic retreat of glaciers that once covered much of the Northern Hemisphere, was already under way when the extinction of woolly mammoths began".
And:
"The Earth already was warming at the time when mammoths were disappearing, but there is evidence that dramatic growth of vegetation in the far North followed the large animals' demise rather than preceded it, Field said".
"The flourishing of plant life as the voracious, vegetarian beasts were disappearing about 15,000 years ago helped warm the Arctic and boreal regions in what is now Siberia and North America by 0.2 degrees Celsius over a period of several centuries, though certain spots saw a temperature rise of up to 1 degree Celsius, the study found".
"The research attributes about a fourth of the Arctic's vegetation-driven warming to the decline of the woolly mammoth. If human hunters helped kill off the large mammals, they bear some responsibility for warming the climate, the scientists concluded".
This link dodges around the issue of human contribution to extinction but the evidence they quote is actually pretty convincing:
http://doc.rero.ch/lm.php?url=1000,43,39,20091210000402-ZZ/PAL_E278.pdf
"I'm sure I've even used the term 'saturation point' for when the human population was sufficient to cause extinctions".
I don't recall you using that sentence. It changes your position a lot in fact.
"I presume you won't even read these extracts let alone the whole article".
I did read it though. The whole tone is speculative, contrary to your usual hyper-affirmative one. For that article the effect of human hunt in extinction (and therefore in warming) is conjectural and not proven, for you it's a 'fact' like the force of gravity.
You don't seem aware of the emphasis and alleged certainty you add to your claims (not just this one), never suggestions nor speculations but always absolutist claims.
Your quotes from the article:
"The end of the last Ice Age, marked by a worldwide rise in temperatures and the dramatic retreat of glaciers that once covered much of the Northern Hemisphere, was already under way when the extinction of woolly mammoths began".
Precisely. That's why global warming could not have been caused by mammoth extinction -- the opposite remains a strong possibility. In association with human pressure? Could be but it does not look at all like the sole cause.
"... there is evidence that dramatic growth of vegetation in the far North followed the large animals' demise rather than preceded it"...
Ok, that's something. It is limited to the restricted environment of the Far North and there is no comparison with previous interglacial periods but it's a hint for a limited region.
""The research attributes about a fourth of the Arctic's vegetation-driven warming"...
This I do not understand. It should be "warming-driven vegetation change", not the other way around. After all, our Interglacial is not much different from previous interglacial periods, maybe kept warmer for long because of anthropogenic forces (farming, herding) but that was about it (before industrialization, it seems).
I'll read later Stuart's paper but I understand these various viewpoints are all part of an ongoing debate.
In any case, it's obvious that mammoths vanish from Europe (where there was always more people than in Siberia) at the time of the collapse of the Ice Age, not before. However I notice on quick look that the latest dates for East Europe and Scandinavia are somewhat older than those for West Europe (in spite of West Europe being warmer and less apt for cold steppe/tundra beasts), what may indeed have an anthropogenic explanation.
Possibly the peoples living there, were more dependent on mammoth or just used to hunt it and that caused maybe their destructive derive (if correct). This is no evidence for any sort of universal pattern but for varied patterns in different situations in fact.
From Stuart 2005:
Why large mammals in particular?
"Analyses presented by Johnson (2002) indicate that vulnerability to extinction was correlated with low fecundity, not directly with body size, although large mammals are also slow-breeders".
Why the extinction in Europe?
"Shortly before ca.12 kyr, mammoth disappeared entirely and rather suddenly from Europe and most of northern Asia (...). Significantly, this
dramatic event does not correlate with the marked warming and spread of shrub-grassland vegetation over much of Europe, which occurred at the beginning of the Late Glacial Interstadial (LGI) ca. 13–12.6 kyr (earlier in some regions), but does correlate with the major loss of open biomes at the onset of the rather cooler Allerød (later part of the LGI) when boreal birch and pine woodland became widely established".
So it were the trees after all, yes!
This passage let me wondering:
"... it is not at all clear why
mammoth did not reoccupy all of the steppe-tundra biome that once again covered most of central and northern Europe".
Obviously, would only have been human presence directly, they would have needed to re-occupy the area before becoming a prey, what would have left evidence in form of bones (hunted or naturally dead), so this sounds rather an unlikely explanation.
There could be ecological barriers of some sort effectively blocking the rediscovery and recolonization by these elephants. For example if horses and oxen ate all the tall grass they could not eat anything.If there were conifer forests, that's a resource very hard to bite for any herbivore (they are rather toxic).
Recolonizing for elephants may have been something to do slowly, generation after generation (they are cultural), as new opportunities appear or new needs demand it. But if there were barriers they could not overcome, at least not easily, and no enough time to recover numbers ("only" 2000 years passed between forest expansion and temporary steppe restoration) so there was any immediate need (demic pressure), this simply would not (and did not) happen.
...
One impression I have from what I read is that mammoths became refuged in the tundra (Taimir peninsula, Wrangle Is.), north of the taiga belt of forests. They are mentioned returning to Scandinavia but that would have been more directly connected to the Taiga refuge than other "temperate" areas. This barrier should have kept them out from ever returning to the steppe, at least they would have needed some time and some temporary corridor through the conifer forest.
Maybe in the previous Interglacials, mammoths had also become isolated in the Taiga and reconolonized from there when the cold came back. But in this case they are talking of a short oscilation, not the return of the Ice Age. Not yet. So the conditions that allowed mammoths to recolonize were not yet present, because they need more time to find that opportunity of crossing the conifer forest belt.
"... if the extinctions of these, and other megafaunal species, were driven solely by environmental change, then why did similar extinctions not occur in previous glacial–interglacial cycles?"
Because of human pressure of some sort maybe, specially in their refuges. But they admit above that Siberia is so vast and unexplored that it's very possibly that other refuges, besides Wrangel Island did exist.
It's difficult to imagine a handful of Arctic foragers, living in nuclear family economic units (as the Nganasan or Inuit still do) going around all the Siberian vastness in search of the last mammoth, for which they would need to make a huge organizational effort to hunt, as one or two hunters cannot spear down such a beast. No, they ate other stuff, as they do today, like fish, sea mammals, reindeer, etc.
So I do not really know why mammoths became extinct in Wrangel Is. and Taymir Peninsula this time.
All I say is: look at the big picture, ponder the whats, whens, wheres and whys, and also the not-knowns, and take it easier. The reasons involved were surely complex and it's clear that human presence was a factor. But we do not know what kind of factor, how decisive and if there were variable reasons in different areas.
Climate change happened in any case on its own reasons, reasons that neither humans nor elephants were able to influence much. And this was a huge solo factor on its own right. Furries were hurt and hairless apes favored with warming, at least in the colder parts of Eurasia. But neither one caused that warming.
And whatever the ultimate trigger of the mammoth extinction, human or not, they were already very hardly pressed by global warming alone, specially the expansion of conifer trees that they could not eat for sure.
"It's difficult to imagine a handful of Arctic foragers, living in nuclear family economic units (as the Nganasan or Inuit still do) going around all the Siberian vastness in search of the last mammoth"
I doubt that any 'last' mammoth in any particular region was actually killed by humans. The splintering of their range through hunting would have led to inbreeding and extinction (sorry, but there we go again).
"I don't recall you using that sentence. It changes your position a lot in fact".
I may have simplified so I didn't always have to write a more detailed explanation.
"For that article the effect of human hunt in extinction (and therefore in warming) is conjectural and not proven, for you it's a 'fact' like the force of gravity".
If we actually consider the evidence rationally we can see at once that climate warming cannot possibly have been the cause of megafauna extinction. I'll grant it could have been the case locally in the Iberian peninsular. The less specifically cold-adapted steppe mammoth probably did not have access to the peninsular (and was already extinct anyway).
For a start you have to remember that ecological zones simply move north or south with changing climate. The article you posted originally even admits that several species did simply move north:
"Some species such as the reindeer and the arctic fox found their new habitat in the arctic regions of the planet, where they still survive today".
But the ecological zone able to move north at the time had changed. A major component had been eliminated: the megafauna.
Next, consider the species that did manage to move north that had co-existed with the megafauna in Spain. The reindeer is still extremely common across northern Eurasia and northern North America. Admittedly in a semi-domesticated state in Eurasia. But, surely, if reindeer have survived in such large numbers mammoths and rhinos should have had no trouble doing so either.
And what about the saiga?
http://en.wikipedia.org/wiki/Saiga_Antelope
"During the Ice Age the saiga ranged from the British Isles through Central Asia and the Bering Strait into Alaska and the Yukon".
"Today they are found only in a few areas in Kalmykia (Russia), Kazakhstan, and western Mongolia".
"At the beginning of the 18th century it was still distributed from the shores of the Black Sea, the Carpathian foothills and the northern edge of the Caucasus into Dzungaria and Mongolia".
So their demise was not ice age related. The main threat to their survival was the high-powered rifle. Presumably the saiga was agile enough to escape from spears and arrows, and so it survived until recently.
The other species mentioned in your original link :
"the wolverine (Gulo gulo), the arctic fox (Alopex lagopus), the musk-ox (Ovibos moschatus)"
are reasonably widespread today, able to colonise a variety of semi-arctic habitats. We cannot overlook the possibility that the megafauna had also been capable of colonising a similar variety of habitat. In fact we know that the mammoth, at least, was able to do so. Only in the extreme northern cold did it become the 'woolly' mammoth. Other mammoth species existed to the south in both Eurasia and North America. How could climate warming have caused their extinction? Surely they would simply have moved north with the appropriate ecological zone.
So we are left with no other conclusion than that climate warming was definitely NOT reasponsible for megafauna extinction. We'll have to find some other excuse if (as so many people are) we are desperate to eliminate human expansion (both in range and in numbers) as being responsible.
"If we actually consider the evidence rationally we can see at once that climate warming cannot possibly have been the cause of megafauna extinction. I'll grant it could have been the case locally in the Iberian peninsular".
Your own reference admits it is in fact the case for West and Central Europe as a whole. New conifer forests impeded mammoth lifestyle.
"... ecological zones simply move north or south with changing climate".
Generally speaking, of course. But there must have been many local and temporal variations as climate changed in either direction. This fine detail, which may have been decisive, we probably cannot grasp.
"The reindeer is still extremely common across northern Eurasia and northern North America".
It is not a steppe animal anyhow but a tundra/taiga specialist. Was the mammoth the same? It should not as SW Europe was more like steppe or something we could call 'oceanic steppe' (more humid and somewhat more temperate than our usual idea of steppe).
"But, surely, if reindeer have survived in such large numbers mammoths and rhinos should have had no trouble doing so either".
Could mammoths live in the taiga, which is the largest range of the reindeer?
"And what about the saiga?"
A steppe animal that lives in the steppe. When the steppe disappeared in most of Europe, so did the saiga.
"So their demise was not ice age related".
I'd say it was in Western Europe. Later it has been hunted to near extinction but that seems a very recent (industrial era) development mostly (on your own quotes).
"So we are left with no other conclusion than that climate warming was definitely NOT reasponsible for megafauna extinction".
You run too fast on too instable ground. There's nothing conclusive in what you say.
For instance is not the musk ox "megafauna"? In America, when talking of "megafauna extinctions" this includes the horse... but not the moose, for instance. In Europe the term typically includes the bison (did not go totally extinct but almost), but not in America, and for some also the horse (which would have been later replenished from Asia/Eastern Europe, after the Neolithic).
It's a complex (and incomplete) puzzle. But the same I find hard to visualize Arctic nuclear families hunting mammoth at all, I find almost impossible to imagine maybe more numerous steppary bands hunting horses to extinction before horse domestication itself - because horses are damn fast, you know. They could be hunt somehow, I imagine, but not as intensively as to annihilate them or anything even close.
So I still think climate change and the advance of forests was the main factor, if not the only one, in megafauna extinctions. Humans probably acted as extra pressure but at Epipaleolithic technological levels they cannot really be held responsible, much less single them out as the only or main culprits.
"New conifer forests impeded mammoth lifestyle".
Not so. Most of the links point out very specifically that the expansion of conifer forests post-dates the demise of the mammoths.
"It is not a steppe animal anyhow but a tundra/taiga specialist. Was the mammoth the same?"
Quite likely. Your original link certainly claims mammoth, reindeer and saiga shared the same environment.
"A steppe animal that lives in the steppe. When the steppe disappeared in most of Europe, so did the saiga".
But, unlike the mammoth and the rhino, it did not become completely extinct.
"Later it has been hunted to near extinction but that seems a very recent (industrial era) development mostly (on your own quotes)".
My point was that, again unlike the mammoth and rhino with which it had shared a similar environment, it did not become extinct til much later. Surely if climate warming was responsible for the mammoth and rhino extinction the same warming should also have dealt to the saiga.
"In Europe the term typically includes the bison (did not go totally extinct but almost)"
But again they survived the 'destructive' global warming at the end of the ice age.
"I find hard to visualize Arctic nuclear families hunting mammoth at all, I find almost impossible to imagine maybe more numerous steppary bands hunting horses to extinction before horse domestication itself ... at Epipaleolithic technological levels they cannot really be held responsible, much less single them out as the only or main culprits".
We do not know what different hunting methods these Upper Paleolithic people used for the different game they hunted. As you say:
"It's a complex (and incomplete) puzzle".
"Most of the links point out very specifically that the expansion of conifer forests post-dates the demise of the mammoths".
Stuart's paper (your input) says clearly that tree expansion is coincident with the disappearance of mammouths in Central Europe. The article linked in the main post says the same for (North) Iberia.
So which are "most links" for you?
"Your original link certainly claims mammoth, reindeer and saiga shared the same environment".
They cannot. Because the saiga is a steppe animal and the reindeer a tundra/taiga one. These are different environments.
"But, unlike the mammoth and the rhino, it did not become completely extinct".
So? It's a smaller animal and, like most antelopes everywhere, should be much more numerous than elephants and rhinos together.
In Africa, for instance, elephants and rhinos are intermittently nearing extinction but this does not happen to gnus or springboks. They can withstand greater loss of habitat, they need less to survive.
"But again they survived"...
So? They did suffer the consequences. Some survived barely, others did not. Do you think mammoths are easier to hunt than bisons? No.
"We do not know what different hunting methods these Upper Paleolithic people used for the different game they hunted".
Spears and harpoons. Lots of harpoons!
"Spears and harpoons. Lots of harpoons!"
And running animals off cliffs. And chasing them with fire.
"They cannot. Because the saiga is a steppe animal and the reindeer a tundra/taiga one. These are different environments".
The link in your original post says:
"The presence of the woolly mammoth (Mammuthus primigenius), the woolly rhinoceros (Coelodonta antiquitatis), the reindeer (Rangifer tarandus), and to a lesser extent the wolverine (Gulo gulo), the arctic fox (Alopex lagopus), the musk-ox (Ovibos moschatus) and the Saiga antelope (Saiga tatarica), has been linked to the paleoclimatic scale created on the basis of the isotopic composition of oxygen in the ice of Greenland".
And:
"The increase in temperatures caused a genuine biological crisis for these animals from extremely cold climates. Some species such as the reindeer and the arctic fox found their new habitat in the arctic regions of the planet, where they still survive today. Others, such as the woolly mammoth and the woolly rhinoceros weren't so lucky,' specifies the paleontologist".
Sounds as though they group them all together.
"So which are 'most links' for you?"
I agree that the Stuart paper dodges round the issue but raises questions as to which came first, the warming and spread of forest or the demise of the mammoth. But this one is definite:
http://www.reuters.com/article/idUSTRE66E17R20100715
That one says:
"The Earth already was warming at the time when mammoths were disappearing, but there is evidence that dramatic growth of vegetation in the far North followed the large animals' demise rather than preceded it, Field said".
This link concerns the same authors but has additional information:
http://www.cosmosmagazine.com/news/3186/mammoth-extinction-altered-american-ecosystem?page=0%2C0
"The extinction of mammoths in North America at the end of the last ice age was not caused by a change in the ecosystem: it's what triggered the changes"
"It shows that the megafaunal decline, including mammoths and mastodons, took about 1,000 years. The decline also preceded major habitat change, increased incidence of fire in the landscape, and a presumed comet or asteroid impact estimated to have occurred around 12,900 years ago".
"After the extinctions came a habitat transformation, with an increase in woody biomass. 'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains', said Williams".
"This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
But obviously you prefer to hide behind your prejudices rather than look at ALL the evidence. So I guess I might as well give up.
"And running animals off cliffs".
Is there evidence for such kind of hunt after Neanderthals? Anyhow, there are no cliffs in the steppe, as it is generally flat.
Fire has not been detected as method either. However it's possible that they used nets or poisons but what is most likely is that they focused on what was at hand and abundant, and that was not the case with mammoths, specially after climatic change.
"Sounds as though they group them all together".
They are talking of animals that lived in West Europe in the Ice Age but not later. But obviously reindeer and saiga needed different environments then as they need them today. There are no reindeers in the steppe and therefore it's likely they were not either in the Ice Age. Similarly there are no saigas in the tundra...
Maybe I'm missing something but sounds quite logical, right?
This lack of precision regarding climatic zones in Pleistocene Europe is something quite chronic but undesirable. You often read "steppe-tundra", as if this was a real ecosystem and not an amalgamation of several ones. This may be because prehistorians are not sure or have not built a consensus on the details but it's not because there were no such climatic zones, more or less well defined in the past.
What links the mammoth to the reindeer is that both need cold and more or less open pastures. I really do not see mammoths in the environment of saigas and horses (steppe) but I may perfectly be wrong in this.
"I agree that the Stuart paper dodges round the issue but raises questions as to which came first, the warming and spread of forest or the demise of the mammoth".
It says clearly that, in Central Europe, the mammoth vanished because of forest expansion. I already quoted that paragraph a couple of posts above.
"The Earth already was warming at the time when mammoths were disappearing, but there is evidence that dramatic growth of vegetation in the far North followed the large animals' demise rather than preceded it, Field said".
Well, so what killed mammoths in the Far North, where human presence is late and extremely scarce?
I don't think it's "definitive" as you say.
"We're not saying this was a big effect. The point of the paper isn't that this is a big effect. But it's a human effect."
So there's a minimal effect that they speculate is of human cause. Why?
"It was not possible, however, to quantify how much of the extinction was due to human hunting, he said. Whether hunters ultimately pushed mammoths over the brink remains a subject of scientific debate".
So dodging around while trying to cast doubt without any useful evidence.
The other link is similarly inconclusive. They find something and argue it's because of the demise of mammoths but this is far from clear.
IMO the case is fully open and, as I said before, slightly different circumstances may have been at play in different regions. It's not the same West Europe than the Eurasian plains or North America.
And in order to blame human hunters, we'd need to have at least some evidence of the butcheries, some evidence of them eating/killing mammoth in large numbers. AFAIK there's nothing of that. There's such evidence for the Neanderthal line (at least in Atapuerca, a key pass) but this did not destroy the megafauna either.
"But obviously you prefer to hide behind your prejudices rather than look at ALL the evidence".
I look at all the evidence and see nothing directly (or even indirectly with any clear weight) blaming humans. Either the human factor was very subtle (subtle alterations can have severe consequences, specially in chaotic circumstances as radical climate change) or we need some clear evidence of humans actually hunting mammoth and woolly rhinoceros.
Now can YOU look at the evidence, or rather lack of it, and accept that the case cannot be judged, certainly not in the sense you want.
"Is there evidence for such kind of hunt after Neanderthals?"
I'm told by someone who grew up there that the evidence is overwhelming in North America evidently, although much more for bison rather than mammoths. And rhinos did not live in America.
"Maybe I'm missing something but sounds quite logical, right?"
To me it seems there is no other way to read the article without concluding the authors mean they all lived together, at the same time. Of course others may prefer not to read it that way.
"It says clearly that, in Central Europe, the mammoth vanished because of forest expansion".
As far as I remember the article says 'coincides with', which leaves open which was cause and which was effect. At least the Stuart paper is honest enough to admit the huge problems associated with the climate warming excuse. An honesty you are not at all prepared to consider.
"You often read 'steppe-tundra', as if this was a real ecosystem and not an amalgamation of several ones".
The term does actually refer to 'a real ecosystem', and prehistorians are generally sure on the details. But the steppe-tundra could also be called 'an amalgamation of several ones', because it was closely interconnected and mixed. The extinction of the megafauna led to the destruction of such complex ecosystems.
"Well, so what killed mammoths in the Far North, where human presence is late and extremely scarce?"
Isn't that is precisely where mammoths survived until that 'late' period? I leave you to draw your own conclusion.
"The other link is similarly inconclusive. They find something and argue it's because of the demise of mammoths but this is far from clear".
Only if you choose to ignore their evidence, but that is your prerogative.
"we need some clear evidence of humans actually hunting mammoth and woolly rhinoceros".
There is, certainly in North America. But of course other explanations are immediately invented.
"I look at all the evidence and see nothing directly (or even indirectly with any clear weight) blaming humans"
Because you choose not to see it. Anyone, apart from those deliberately blind, can see that the climate warming excuse for megafauna extinction is complete baloney.
When the US government could see a financial advantage in the concept of promoting an advanced rocket system the asteroid collision hypothesis was encouraged. I presume you accepted that hypothesis at the time.
When the drug companies could see a financial advantage in promoting the concept of an influenza epidemic the disease hypothesis was encouraged. I presume you accepted that hypothesis at the time.
These days, when the share market can see a financial advantage in promoting the concept of trading carbon credits, the climate change hypothesis is encouraged. I note that you now accept that hypothesis without question.
It is difficult to see any financial advantage arising from promoting the concept of human environmental destruction, ancient or modern. So that hypothesis is systematically discouraged.
"As far as I remember the article says 'coincides with', which leaves open which was cause and which was effect".
There is massive agreement that climate change was what allowed forest to expand. Forests have expanded and contracted in Africa without elephants going extinct. In fact there are many elephants that live IN tropical forests (both in Africa and Asia) without ever reducing their size, except for small clearings maybe. Elephants are not able to regulate forests alone.
"The term does actually refer to 'a real ecosystem', and prehistorians are generally sure on the details".
No. I have a good manual on European prehistory detailing to some extent the extension of steppe (two subtypes: loess steppe, a rich habitat, and dry steppe, poor), forested areas (Mediterranean), taiga and tundra. There were climatic belts as now just that they were further south.
For example the Rhine-Danube and Dniepr-Don provinces were loess steppe essentially (and were populated), North France and the Balcans were dry steppe (and were scarcely populated). Near the ice line there was taiga and tundra.
The most complex case seems to be the Franco-Cantabrian region, which was, I understand, something like "oceanic steppe" (more humid and temperate) but with many sub-niches shaped by relief, which added diversity of ecology and hence economy (some of the most densely populated areas were near the mountains).
There was no steppe-tundra but this category means in fact steppe plus taiga plus tundra, with some fluctuations (not always well understood) because of climate variation.
"Only if you choose to ignore their evidence"...
What evidence? Detail please.
"When the US government could see a financial advantage in the concept of promoting an advanced rocket system the asteroid collision hypothesis was encouraged. I presume you accepted that hypothesis at the time".
You presume wrong. I always considered the risk of asteroid collision and the hypothetical plans to avert them as a wacko idea and a waste of time and resources. We'd better spend all those resources in preventing the ecological WE are pushing ahead with no respect for ourselves or future generations. What's the whole point of preventing a hypothetical asteroid collision in the year 2100 if we have already destroyed Earth ourselves before that date?
"When the drug companies could see a financial advantage in promoting the concept of an influenza epidemic the disease hypothesis was encouraged. I presume you accepted that hypothesis at the time".
Again wrong.
"These days, when the share market can see a financial advantage in promoting the concept of trading carbon credits, the climate change hypothesis is encouraged. I note that you now accept that hypothesis without question".
I disagree with that logic. Climate change is a real problem even if the Tokyo system is plainly idiotic. Only an Earth-level of socialist (and ecologist, and genuinely democratic) economic planning can deal with this problem (and the other ecological problems caused by over-consume, in turn caused by productivism, by Capitalism).
"It is difficult to see any financial advantage arising from promoting the concept of human environmental destruction, ancient or modern. So that hypothesis is systematically discouraged".
Or from promoting the opposite viewpoint. In this case we are before a true scientific debate. However our prejudices on humankind can bias our perception of the problem.
You could accuse me of having a bias for an idealized sustainable forager economy, in turn I can accuse you of projecting modern woes (anthropogenic climate change) on a reality that has no comparison.
In fact I wonder how can you be as skeptical of modern anthropogenic warming (when we are managing energies and technologies that can destroy Earth as we know it in a day or few) and instead as fanatic of Paleolithic anthropogenic warming, when our technologies and densities were extremely limited. How?
"In fact there are many elephants that live IN tropical forests (both in Africa and Asia) without ever reducing their size, except for small clearings maybe".
So why do you automatically assume mammoths couldn't?
"What evidence? Detail please".
From the article:
"The researchers used fossils, pollen, charcoal and dung fungus spores, along with radiocarbon dates, to build a more accurate picture of the sequence of events at the end of the last ice age. They found a decline of Sporormiella dung fungal spores, began around 14,800 years ago, leading to its virtual disappearence 13,700 years ago, said Jacquelyn Gill, study leader and a graduate student in Williams' lab".
And:
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
And:
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
And:
"'There is evidence for similar changes in vegetation following megafaunal extinction in other parts of the world, but the data from this new study are especially well-resolved, and make the cause-effect relationship very clear,' Johnson told Cosmos Online".
Back to your beliefs:
"I have a good manual on European prehistory detailing to some extent the extension of steppe (two subtypes: loess steppe, a rich habitat, and dry steppe, poor), forested areas (Mediterranean), taiga and tundra. There were climatic belts as now just that they were further south".
That conflicts with what I've read. My understanding is that there was far more overlap between the various climate belts before the megafauna died out. Anyway that doesn't affect the impossibility of climate warming having caused megafauna extinction.
"Climate change is a real problem"
I agree.
"In fact I wonder how can you be as skeptical of modern anthropogenic warming (when we are managing energies and technologies that can destroy Earth as we know it in a day or few) and instead as fanatic of Paleolithic anthropogenic warming, when our technologies and densities were extremely limited. How?"
As I said, I'm not sceptical of modern anthropogenic warming. But I would argue that the emphsis on climate change being responsible for the demise of the mammoth is a product of the economic advantages of having people accept it. I also didn't really come up with the correct expression when I said, 'human environmental destruction, ancient or modern'. A better expression would be 'the over-exploitation of resources'. In fact I'm certain that is currently a far bigger problem than anthropogenic climate warming. What I should have written was, 'It is difficult to see any financial advantage arising from promoting the concept of human over-exploitation of resources'. And this leads inexorably to consideration of an even more taboo subject: over-population.
"In fact there are many elephants that live IN tropical forests (both in Africa and Asia) without ever reducing their size, except for small clearings maybe".
So why do you automatically assume mammoths couldn't?
"What evidence? Detail please".
From the article:
"The researchers used fossils, pollen, charcoal and dung fungus spores, along with radiocarbon dates, to build a more accurate picture of the sequence of events at the end of the last ice age. They found a decline of Sporormiella dung fungal spores, began around 14,800 years ago, leading to its virtual disappearence 13,700 years ago, said Jacquelyn Gill, study leader and a graduate student in Williams' lab".
And:
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
And:
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
And:
"'There is evidence for similar changes in vegetation following megafaunal extinction in other parts of the world, but the data from this new study are especially well-resolved, and make the cause-effect relationship very clear,' Johnson told Cosmos Online".
Back to your beliefs:
"I have a good manual on European prehistory detailing to some extent the extension of steppe (two subtypes: loess steppe, a rich habitat, and dry steppe, poor), forested areas (Mediterranean), taiga and tundra. There were climatic belts as now just that they were further south".
That conflicts with what I've read. My understanding is that there was far more overlap between the various climate belts before the megafauna died out. Anyway that doesn't affect the impossibility of climate warming having caused megafauna extinction.
"Climate change is a real problem"
I agree.
"In fact I wonder how can you be as skeptical of modern anthropogenic warming (when we are managing energies and technologies that can destroy Earth as we know it in a day or few) and instead as fanatic of Paleolithic anthropogenic warming, when our technologies and densities were extremely limited. How?"
As I said, I'm not sceptical of modern anthropogenic warming. But I would argue that the emphsis on climate change being responsible for the demise of the mammoth is a product of the economic advantages of having people accept it. I also didn't really come up with the correct expression when I said, 'human environmental destruction, ancient or modern'. A better expression would be 'the over-exploitation of resources'. In fact I'm certain that is currently a far bigger problem than anthropogenic climate warming. What I should have written was, 'It is difficult to see any financial advantage arising from promoting the concept of human over-exploitation of resources'. And this leads inexorably to consideration of an even more taboo subject: over-population.
"In fact there are many elephants that live IN tropical forests (both in Africa and Asia) without ever reducing their size, except for small clearings maybe".
So why do you automatically assume mammoths couldn't?
"What evidence? Detail please".
From the article:
"The researchers used fossils, pollen, charcoal and dung fungus spores, along with radiocarbon dates, to build a more accurate picture of the sequence of events at the end of the last ice age. They found a decline of Sporormiella dung fungal spores, began around 14,800 years ago, leading to its virtual disappearence 13,700 years ago, said Jacquelyn Gill, study leader and a graduate student in Williams' lab".
And:
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
And:
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
And:
"'There is evidence for similar changes in vegetation following megafaunal extinction in other parts of the world, but the data from this new study are especially well-resolved, and make the cause-effect relationship very clear,' Johnson told Cosmos Online".
Back to your beliefs:
"I have a good manual on European prehistory detailing to some extent the extension of steppe (two subtypes: loess steppe, a rich habitat, and dry steppe, poor), forested areas (Mediterranean), taiga and tundra. There were climatic belts as now just that they were further south".
That conflicts with what I've read. My understanding is that there was far more overlap between the various climate belts before the megafauna died out. Anyway that doesn't affect the impossibility of climate warming having caused megafauna extinction.
"Climate change is a real problem"
I agree.
"In fact I wonder how can you be as skeptical of modern anthropogenic warming (when we are managing energies and technologies that can destroy Earth as we know it in a day or few) and instead as fanatic of Paleolithic anthropogenic warming, when our technologies and densities were extremely limited. How?"
As I said, I'm not sceptical of modern anthropogenic warming. But I would argue that the emphsis on climate change being responsible for the demise of the mammoth is a product of the economic advantages of having people accept it. I also didn't really come up with the correct expression when I said, 'human environmental destruction, ancient or modern'. A better expression would be 'the over-exploitation of resources'. In fact I'm certain that is currently a far bigger problem than anthropogenic climate warming. What I should have written was, 'It is difficult to see any financial advantage arising from promoting the concept of human over-exploitation of resources'. And this leads inexorably to consideration of an even more taboo subject: over-population.
"So why do you automatically assume mammoths couldn't?"
I do not "assume" anything. But it seems mammoths did never live in forests. Anyhow, there's a difference between the rich and nutritious tropical forests and the monotonous taiga ones, made of conifers which are typically not edible but by some very specialized animals.
I understand that mammoths could not feed on conifers, while elephants may and do feed on tropical forest varied trees and their nutritious fruits.
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
I was a little frustrated with this sentence because it does not specify which two two tree taxas are the ones that may have fed the mammoth. You are forced to believe what they say without being able to analyze it. Are these trees conifers? Deciduous? What?
Anyhow, you mention that evidence but I fail to see how it proves your hypothesis. All it says is that as the tree line advances with climate change, mammoths recede.
"That conflicts with what I've read. My understanding is that there was far more overlap between the various climate belts before the megafauna died out".
It's not what I have read in any case. I may be wrong but I'd like some clear references in order to change my mind, if need be, on solid ground.
"And this leads inexorably to consideration of an even more taboo subject: over-population".
Actually, while over-population may be a problem, the real problem is overproduction and overconsumption. Most people even today have a negligible ecological footprint, while the very rich and institutions from wealthy states are the ones who damage the environment the most.
Maju. You are very definite that you will not let the evidence interfere with your belief.
"Anyhow, you mention that evidence but I fail to see how it proves your hypothesis".
Of course you fail to see it. In fact you are totally committed to not seeing it. And I can't see my last post here although you reply to it.
"I was a little frustrated with this sentence because it does not specify which two two tree taxas are the ones that may have fed the mammoth".
It should be a simple matter to track down the original article, but seeing that you are already committed to not believing them I'm sure you will not try to find it.
"Most people even today have a negligible ecological footprint, while the very rich and institutions from wealthy states are the ones who damage the environment the most".
Not entirely correct. What the poorer people lack in individual imprint they make up for in absolute numbers.
"Climate change is a real problem"
I agree.
"In fact I wonder how can you be as skeptical of modern anthropogenic warming (when we are managing energies and technologies that can destroy Earth as we know it in a day or few) and instead as fanatic of Paleolithic anthropogenic warming, when our technologies and densities were extremely limited. How?"
As I said, I'm not sceptical of modern anthropogenic warming. But I would argue that the emphasis on climate change being responsible for the demise of the mammoth is a product of the economic propaganda advantages of having people accept it. I also didn't really come up with the correct expression when I said, 'human environmental destruction, ancient or modern'. A better expression would be 'human over-exploitation of resources'. In fact I'm certain that over-exploitation of resources is currently a far bigger problem than anthropogenic climate warming. What I should have written was, 'It is difficult to see any financial advantage arising from promoting the concept of human over-exploitation of resources'. And this leads inexorably to consideration of an even more taboo subject: over-population.
"What evidence? Detail please".
From the article:
"The researchers used fossils, pollen, charcoal and dung fungus spores, along with radiocarbon dates, to build a more accurate picture of the sequence of events at the end of the last ice age. They found a decline of Sporormiella dung fungal spores, began around 14,800 years ago, leading to its virtual disappearence 13,700 years ago, said Jacquelyn Gill, study leader and a graduate student in Williams' lab".
Dates the disappearance of megafauna pretty accurately. And:
"'Our record shows, as Sporormiella declines, we see increase in the abundance of two tree taxas that have very similar pollen grains,' said Williams. This led them to believe that these trees, which according to Gill have a higher nutrient content and are softer to the palate, may have been present before the decline and extinction of the megafauna, but were being kept at bay by the large herbivores".
And:
"'There is evidence for similar changes in vegetation following megafaunal extinction in other parts of the world, but the data from this new study are especially well-resolved, and make the cause-effect relationship very clear,' Johnson told Cosmos Online".
More evidence. A few other comments regarding Paleolithic mammoth hunters:
http://www.sciencedaily.com/releases/2010/04/100412100017.htm
“The site includes the remains of a Clovis hunters' camp close to a mammoth and a bison kill site”
No problems there about whether or not.
http://en.wikipedia.org/wiki/Clovis_culture
“It is generally accepted that Clovis people hunted mammoth as Clovis points have repeatedly been found in sites containing mammoth remains.”
http://en.wikipedia.org/wiki/Animal_Usage_in_the_Gravettian
“In Central Europe, mammoths were a prime food source for the people of Central Europe. It is believed that human exploitation, in this manner, has led to their extinction.”
"Maju. You are very definite that you will not let the evidence interfere with your belief".
You too. And worse: you are "very definite" that you will keep accusing me of preconceptions ("belief") instead of performing meaningful discussion.
"It should be a simple matter to track down the original article, but seeing that you are already committed to not believing them I'm sure you will not try to find it".
Ahem. The link is in the main post. It's pay per view. :(
"What the poorer people lack in individual imprint they make up for in absolute numbers".
Not true. A few wealthy consumers have much more impact than millions of poor subsistence farmers.
There's where the problem lies and why the overpopulation fallacy is a fallacy.
Said that, there's no point in growing indefinitely in such a small planet but the real problem is not overpopulation but overconsumption.
Post a Comment