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No luck yet. Of course it may not have been published on net yet.

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>>"what was the Canadian tundra like when humans do seem to have come that way?"<<

You may find this helpful: http://www.museum.state.il.us/exhibits/larson/larson_top.html

The tundra was virtually the same then as it is now, only the latitude changed. Polar conditions (glaciers) extended down almost to the Ohio River Valley, with tundra existing south of that.

The Pacific coast was many miles west of its present day location, and probably warmed then, as now by the Japanese current, and kept ice free.

Note that the Great Plaines of Canada and the US remain flat and unscarred by glaciers as is the land around the Great Lakes and to the east- apparently ice free during the Ice Age.

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Thanks Doc. Makes it even more difficult to explain how a group of humans passed from Alaska, through Canada and onto the US high plain though. Unless DA is correct and they actually came along the west coast for a start.

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I believe the theory is that, while extensive glaciation tied up sizeable amounts of water, lowering the sea leavel, pushing the Pacific coast of NA well to the west and exposing the land bridge from Siberia, the warm Pacific influence kept the weather along the coast mild.

Little evidence of the first migrants is available now, submerged as sea levels rose. They didn't push farther inland until the glaciers started receding.

On the link I provided, click on "Pleistocene Extinctions" to get an animation of glaciation in NA.

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Thanks Doc. I had already done that. I believe the pattern of Pleistocene extinctions give a good indication of the speed and direction of the first human movement into North America. Tends to support the idea they came through the Canadian tundra rather than via the coast though.

Last edited by terrytnewzealand; 03/30/07 03:11 AM.
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I'm not sure I buy into the theory that extinctions of NA great mammals at that time was due to human hunting. It's based mnainly on the coincidence of Man's appearance with the extinctions and the finding of one lousy arrow head in one lousy mammoth rib.

Life was tough in those days, and I'm not sure our ancestors would have taken the risks involved in hunting those large beasts.

Maybe the changing environment (ie- loss of habitat) associated with the extinctions also allowed H sapiens to invade?

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DocT wrote:

"It's based mainly on the coincidence of Man's appearance with the extinctions".

Isn't it funny how man's appearance coincides with animal extinctions right around the world. The extinctions all happen at different times, spread over about 60,000 years. Africa, Australia, Tasmania, Sri Lanka, Central Asia, Northern China, Northern Europe, America, Mediterranean islands, Wrangel Island, Madagascar, New Zealand. We can even date human expansion by the dates of these extinctions. But humans had nothing to do with them. It's only modern humans who have exterminated any species.

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The numbers don't lie. Aside from the fact that something like a Clovis Spearhead would have little effect on a Mammoth or a Megatherium, the small number of humans in NA back then can hardly be held responsible for causing their extinction. I've heard arguments that they set fires to kill Mammoths. Dude, ever seen an elephant run? No way. I've heard that they killed the Mammoths off by going after the babies. One thing you don't do in Africa is piss off a mother elephant. And the Megatherium (Giant Sloth) is believed to have been over 20' tall standing on it's hind legs. I don't care if Raquel Welch wearing a bikini was watching, no Caveman in his right mind would provoke THAT. Even if he had a Clovis Spear. It's widely held today that our "Hunter/Gatherer" ancestors spent a lot more gathering than they did hunting. Scavenging dead carcasses wouldn't have hastened the demise of the American Megafauna either.
No, I agree with doc on this one. We never got "serious" about wiping out other species until we discovered Gunpowder. After that, look out, Baby. On this topic, pick up "Song of the Dodo" by David Quammen. He doesn't get into Mammoths, however, just the stuff we KNOW we've wiped out.

Last edited by Wolfman; 03/30/07 09:13 AM.
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OK. I'll agree then. Everywhere but in America humans wiped out species soon after they arrived. How do you explain that?

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It wasn't as obvious in Europe or Asia. It's quite obvious in island environments where the animal populations are small and habitat limited- that's special conditions.

Consider the case of, say, the Bengal tiger: it's populations are falling, but not really due to hunting. As human population growth encroaches on its habitat, it's being squeezed out. For the tiger, the carrying capacity in the population equation demands several sq mi per beast and they haven't adapted to compensate for that limitation, hence, their population falls. Once it falls below a certain critical level, it is doomed to extinction.

The mathematics of populations is a fascinating study. It seems many of the phenomena we observe are requirements of the system and not due to extraneous pressures. It's kinda like the stock market: after the day ends, the newsman tries to explain the fall in prices were due to news of impending revolt in West Alpha Centauri, but the little old widows who own most of the shares never got the news in the first place. It's really just all in the math.

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Not so fast, Terry. Have you ever read that Paleontologists have wondered why, exactly, did "Modern Man", with his superior brain, take so long to gain a foothold in Europe. Some believe that the Neanderthals already in Europe was able to hold them back. But there was another predator living in Europe at the time that would have given our ancestors a good fight. The Cave Bear, Ursus Spelunka (sp?) was as big as today's Polar Bears. They lasted until 10,000 years ago, until the end of the last Ice Age. After that our people were able to establish themselves.

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On another post Dan wrote:

"And they invest countless hours looking for ghosts, gnomes, sun spots, anything other than the dread taking of personal responsibility by the planet's inhabitants for the mess were are making."

Seems we are also not prepared to look at the possibility we have been doing it for a long time.

Wolfman mentioned "Modern Man, with his superior brain". What evidence do you have that this is so? Technologically superior more likely. But that's another argument. Neanderthals must have been quite capable of surviving the presence of the cave bear. I'd agree with the idea that modern man took a long time to gain a foothold in Europe simply because Neanderthals were already there. They already filled the ecological niche.

Humans would hardly have faced a mammoth alone. Teamwork is what it's all about. As the Doc says small populations are vulnerable to extinction through disasters or inbreeding. This is a problem modern conservationists face all the time. If herds of mammoths were broken into small groups, either by hunting or fires, humans need not have actually killed the last one.

Of course mammoths and sloths were not the only things that died out soon after humans arrived in America. A short list: horses, camels, several species of deer, an antelope related to the pronghorn, giant armadillo, giant beaver, sabertooth and other cats, two types of peccary, tapir, large wolf, two more elephant-type creatures, giant tortoises and many species of birds. all gone within a thousand years of each other. Of course climate change may have been responsible but again it seems strange they had survived previous drastic climate changes but this time they failed to adjust.

Wolfman, close to your home although you may already be aware of this. It is fairly old:

http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/divers2/010020760.pdf

As DocT says the correlation is more obvious on small islands but the correlation exists on continents as well. Here is a more recent comparison between the two. Of course we could say because Paul Martin co-wrote it it's going to be biased:

http://www.eeb.cornell.edu/donlan/readings/Steadman%20and%20Martin%202003.pdf

Last edited by terrytnewzealand; 03/30/07 11:02 PM.
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TNZ wrote:
"Seems we are also not prepared to look at the possibility we have been doing it for a long time."

But we should.

We are the people who gave the American Indians blankets taken from people that died of scarlet fever. We are the people who are responsible for decimating the populations of huge numbers of species (who were the Dodo's really? I suspect not the birds). Who are the people who committed the genocides in Germany? Turkey? Darfur? Bosnia? Rwanda? Who started and fought the 100 years war for 116 years?

Who is poisoning rivers and land?
Who is dumping CO2 into the atmosphere?
Who is ignoring all of the warning signs?

I don't know. Perhaps we should discuss it with the Aztecs or the Kampaa or countless other peoples. Oops. Too late. Guess we can't do that any more.

Why is it things "fail to adjust" just after we arrive? Coincidence?


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High correlation does not imply cause and effect.

The environment to which mammoths, giant wolves, early horses and deer, etc etc were adapted changed at the end of the Ice Age. Those species died off. Already adapted to warmer conditions, H.sapiens expanded its territory to those parts where the others formerly lived. Men and the dying species may well never have interacted.

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Terry, I agree that the mass extinction that took place at the end of the Pleistocene Epoch could appear to be the work of man, but I remain convinced that it was Mother Nature that took the big beasties out. I grew up in British Columbia. We'd read about excavations uncovering Mammoth Molars and/or Tusks all the time. But back then, the Pleisticene, the entire NW quadrant of America was covered in ice. Not an "Ice Cap" per se, but just a large series of Glaciers fused together. It was known as the Cordilleran Ice Sheet. In the NE quadrant a similar Ice Sheet was in place. It is referred to as the Laurentian Ice Sheet. In some areas the Ice ran as far down as the 40th Parallel of latitude. The Canada-US Border follows the 49th parallel.These "Facts and Figures" are burned into my head. We needed to know this if we wanted to pass Fifth Grade History.
And the image of Primitive Man as "The Great Hunter" is a noble one, I admit. But, as a Bowhunter, I've seen a 200 lb. Buck run 200 yards after having a razor-sharp broadhead pass right through both lungs. Don't tell me some Cro-Magnon could take down a Mammoth with a pointed stick!

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DocT writes:

"High correlation does not imply cause and effect."

True. But to jump to the conclusion that the fact the large mammals died out let humans move into America means America becomes a special case. I realise many Americans do believe they are special but let's look at examples from other regions. Extinction of large animals would certainly not have been a factor in letting humans reach islands such as New Zealand, Madagascar, Santa Catalina, Tasmania, Sri Lanka and Australia. In these places, too, large animals died out about the time humans reached them. Perhaps before, but surely their dying out would have had no influence on human ability to reach them. Some other factor is at work, at least in these cases.

Wolfman writes:

"Don't tell me some Cro-Magnon could take down a Mammoth with a pointed stick!"

Ah, but Pygmies have hunted elephants with pointed sticks for centuries, long before they had guns. Certainly it is a dangerous business but even today many humans love taking risks. Besides, a dead elephant can feed a lot of people before it goes rotten. Sure, the first spear thrust probably wouldn't have killed the mammoth but Bushmen often hunt by pursuing their prey in relays. A most effective method.

Just found this regarding Australia:

http://www.answers.com/topic/australian-megafauna

The animal extinctions in America were more recent. It's quite possible they resulted from the same cause.

Last edited by terrytnewzealand; 04/01/07 10:31 AM.
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docT writes:
"High correlation does not imply cause and effect."

That's the argument tobacco made about cigarette smoking.

You are of course correct. One does not guarantee the other.

But it is enough to get a conviction in a court of law.


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I found this. Mainly posting it because I like the moa skeleton walking backwards and forwards across the top:

http://www.archaeology.org/online/features/moa/

However Jared Diamond's comments are worth quoting:

"Is archaeology a useless discipline, irrelevant to the present, and deserving of the late Senator William Proxmire's Golden Fleece Award for wasted research money? Think of all those long-lived plants and animals still being harvested today at unsustainable rates. As Santayana said, those who do not remember the past are condemned to repeat it. Then, there were no more moas; soon, there will be no more Chilean sea bass, Atlantic swordfish, and tuna. I wonder what the Maori who killed the last moa said. Perhaps the Polynesian equivalent of 'Your ecological models are untested, so conservation measures would be premature'? No, he probably just said, 'Jobs, not birds,' as he delivered the fatal blow."

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I agree Pygmys have been known to skewer an Elephant. But they came no where near to making them extinct. And there's a big difference between a 500 pound chicken and a Woolly Mammoth or a Smilodon or a Megatherium or a Cave Bear. I will concede that prehistorric Hunters may have "harrassed" a few Mammoths into Death-By-Chasing, but what about the population of Pygmy Mammoths on Wrangel Island? It's estimated that they survived as recently as 1700 BC. The Inuits there harpooned whales using primitive weapons, but, apparently, they left the Mammoths alone, dispite being far smaller than a regular Mammoth.
I gotta think that it was a reduction in food, caused by all that ice, that was the demise of the Megafauna. Man, opportunistic even back then, just happened to be in the right place at the right time.

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True. No evidence for actual mammoth hunting on Wrangel. But, once again, we have a coincidence between the arrival of humans and extinction of mammoth. You wrote:

"I gotta think that it was a reduction in food, caused by all that ice, that was the demise of the Megafauna."

But climate had fluctuated wildly over the whole time of megafauna's existence. Mammoths had easily adapted to previous extremes of cooling and warming. Besides mammoths became extinct in North America at the end of a cold period but became extinct on the Central Asian steppe during a relatively warm period.

Now, if mammoths survived until 3000 years ago on Wrangel how can we blame climate for their demise on the mainland? The climate 3000 years ago was relatively stable. Presumably mammoth survived on Wrangel simply because humans didn't get there until relatively recently.

The argument that Pygmies haven't caused elephant extinction yet is easily explained by the fact that mammoth hunting appears to have begun on the Central Asian steppe. It's only recently been introduced to Africa. Elephants have been effectively wiped out in Northern Africa but were still found in parts of Syria until 800 BC.

By the way Wolfman. I've tried to find information on prehistoric extinctions on Samoa but have had no success. Has any work been done on the matter?

Last edited by terrytnewzealand; 04/02/07 03:37 AM.
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