Science a GoGo's Home Page Forums General Discussion Climate Change Forum Canadian tundra is rapidly disappearing

Canadian scientists say much of their nation's northern tundra is rapidly disappearing, being replaced by trees and shrubs, forcing wildlife from the region. A University of Alberta study shows the climate shift is occurring at a rate much faster than scientists had predicted, adding to a growing body of evidence concerning effects of global climate change. The boundary, or tree line, between forest and tundra ecosystems is a prominent landscape feature in both Arctic and mountain environments. As global temperatures continue to increase, the tree line is expected to advance, but the new research shows the shift will not always be a gradual one. "The conventional thinking on tree line dynamics has been that advances are very slow," said Ryan Danby, of the university's department of biological sciences. "But what our data indicate is that there was an upslope surge of trees in response to warmer temperatures. It's like it waited until conditions were just right and then it decided to get up and run, not just walk." The research by Danby and David Hik, also from the school's faculty of science, is detailed in the Journal of Ecology. Source: Click Here .

Which set me to wondering what was the region like as the first Americans moved through there? I imagine it would not be very comfortable to travel on foot from Western Alaska to the Northern US plains these days.

The first Americans, it appears, didn't come across a land bridge from Siberia. More and more research is supporting the idea that so-called Native Americans were not the first inhabitants. My guess is that they did to those who were here first what the Europeans did to them. Just more efficiently.

For those that did come across the land bridge from Siberia ... my guess would be that as they migrated it was from worse to better. If you are in Manitoba in January ... Minnesota can look like paradise. <g>

DA you wrote:

"The first Americans, it appears, didn't come across a land bridge from Siberia."

I've seen (on TV, a very reliable source) the stuff about similarities between Solutrean and Clovis spear points. The idea the first americans came via the edge of the ice shelf is hard to accept though. Europeans didn't even have boats capable of reaching islands in the Mediterranean at the time.

Do you have more info. Perhaps another thread as this is perhaps only marginally related to climate change. Not quite science?

DA. So the first ones may have come from Australia via the western shore of the Pacific Ocean. This fits my interpretation of the mtDNA and Y-chromosome evidence for an expansion from Wallacea in my Adam and Eve and history thread. People must have come along the coast and then along the Kurile and Aleutian Islands. The glaciated Rockies may have prevented their access east until they reached Central, or even South, America.

You wrote:

"My guess is that they did to those who were here first what the Europeans did to them."

Seems not. The mtDNA lines C and D remain. They actually came from Mongolia but were probably picked up during the movement north along the coast.

This still leaves the problem of what conditions were like for those who eventually moved east of the Rockies into the North American plains.

Consider this:
http://en.wikipedia.org/wiki/Kennewick_Man

Not related to any known American Indian ancestry.

Again, as with Neandertal, I am see the likelihood of interbreeding. But I can also see the likelihood of genocide.

That is, after all, the way we do business.

See Rwanda, Darfur, and Bosnia for recent examples.

Dan. The article says:

"they were of a man who lived between 5,000 and 9,500 years ago."

This would indicate a pretty rapid genocide for the relatively primitive weapons available. The technology used in Rwanda, Darfur, and Bosnia is far more advanced.

You wrote:

"Not related to any known American Indian ancestry."

How can you say that? There has been no genetic work done on the skeleton. It's extremely likely it represents one of the several migrations into America that gave rise to the pre-European population. We know from Y-chromosome evidence that part of that population moved north of the Central Asian mountains, and probably had their origin with the mammoth hunting people of the Central Asian steppes. Although mitochondrial DNA shows the female side probably came from Mongolia, North China and Korea the present Native Americans look fairly different from the present East Asian people. They are almost certainly a mix of several different kinds (how I love that word) of people, as are all other groups on earth. Including those who like to believe they are unique.

Rwanda was done with machetes not machine guns.

My comment about "not related to any known" is based upon work done here at the University of Washington. Look at this:

http://www.sciencedaily.com/releases/2006/04/060425183740.htm

and I quote:

"Some Ainu?s facial features appear European. Their eyes may lack the Asian almond-shaped appearance, and their hair may be light and curly in color. However, this does not mean that Kennewick Man necessarily was European in origin. His features more closely resemble those of the natives of the Pacific Rim than those of Native Americans."

Dan, you commented:

"Rwanda was done with machetes not machine guns."

The genocide in Rwanda was nowhere near complete. This tells me machetes are inadequate for the purpose.

You quote from the link:

"Their eyes may lack the Asian almond-shaped appearance"

But this is true of most Native americans. That Kennewick Man looks Ainu is hardly surprising. That Ainu look like Papuans is also hardly surprising.

When I visited the USA many years ago I noticed that Native Americans are certainly not an homogeneous type. The closest to my idea of a classic American Indian was the man I met whose ancestors had been absorbed by the Seminoles. Cherokees appeared to contain a fairly large proportion of African ancestry, presumably from a relatively recent input. The Pueblos I met looked like clones of Ho Chi Minh. Mexican Indians looked different to any others. The Apache I met looked a little Polynesian. And Y-chromosome and mitochondrial DNA shows Polynesians a basically a hybrid between East Asians and Melanesians.

There is certainly nothing preposterous in the idea that Native Americans are a product of many human movements. After all, that's how evolution works. It's only the Judeo-Christian idea of evolution that demands new characteristics in a species are a product of the expansion of small groups or even the descendants of just one couple. And always remember Judeo-Christian perspectives are very widespread in the USA.

I see this last one hasn't popped up yet in the Climate Change list.

TNZ wrote:
"The genocide in Rwanda was nowhere near complete. This tells me machetes are inadequate for the purpose."

I disagree. One can not look at a single incident as a completed genocide nor can one compare the large populations that currently exist with those much smaller populations from earlier times.

It is not hard to imagine a group of 100 being extinguished with one or two escaping into the brush and dying of starvation or disease. When you have populations of millions the slaughter will just leave more (numerically speaking) survivors.

True. But I think genocide has been less important during our evolution than you believe it has been. I certainly agree that whole human populations have become regionally extinct at times, but through over-exploitaion of resources and changing climate conditions rather than through direct genocide. I heard something a few weeks ago on the radio some scientist believes humans have become extinct in Europe up to seven times in the past. Most before any new wave of humans entered. Looked briefly on the net for anything but couldn't find it. Maybe you have heard something about it?

You may be right but let me put the following to you ... within your lifetime how many attempts have been made at genocide.

I will start the list for you.

Bosnia
Darfur
Rwanda

.. it is a long list in a very short number of years. And this among "civilized" people with a UN, and EU, and US watching them.

It does go back a long way as well. But in this country we are aware of many attempts at genocide going back well before European discovery. It is seldom any tribe managed to exterminate another. Absorb the survivors, occassionally yes. More usually survivors joined another tribe. It's this level of genocide that has been active through most of our evolution.

Anyway, what was the Canadian tundra like when humans do seem to have come that way?

TNZ asks:
"what was the Canadian tundra like when humans do seem to have come that way?"

I don't know but I will see if I can find out.

My suspicion though is reasonably hospitable as that was the time during which the megafauna existed: Saber toothed kitty cats, Mastodons, etc.

Dan. I made another booboo. Of course humans haven't become extinct in Europe seven times. Just Britain. Still can't find reference although I searched more thoroughly today. Perhaps someone can help? What's this got to do with Canadian tundra? There's obviously been changes in the vegetation in the sub-Arctic many times.

Can you be more explicit as to what it is you are looking for?

I'll try to help.

Thanks Dan. Seems the guy reckoned that H. erectus got into Britain but was pushed back during a cold spell. Likewise H. heidelbergensis, Neanderthals (I spell it the old way because they were named before spelling of the valley changed), even modern humans I think. I don't know how he got seven extinctions but I'm pretty sure I remember the number correctly. Maybe H. erectus got in several times. I remember his accent as being English but my memory may be playing tricks there.

Try this at google:

"Extinction" and "stone age" and "Britain"

for a search

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

>>"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.

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.

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.

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.

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?

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.

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.

OK. I'll agree then. Everywhere but in America humans wiped out species soon after they arrived. How do you explain that?

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.

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.

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

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?

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.

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!

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.

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.

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."

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.

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?

At the risk of being called a troll I'll reply to myself. How's this:

http://llnl.confex.com/llnl/ams10/techprogram/P1297.HTM

And this:

http://www.cq.rm.cnr.it/elephants2001/pdf/363_366.pdf

Seems it wasn't ice or cold that killed mammoths in Asia. In fact the ones in warmer regions died out first!

There are many means by which we might have contributed to extinction without the use of sophisticated machinery.

1. We could have brought in diseases
2. We could have started fires destroying habitat
3. We could have killed to top predators leading to an imbalance with food supplies
4. We may have just been the final insult to a precarious balance

And of course it could just be a coincidence.

Unfortunately we come with a long history of causing extinctions. So coincidence should be rather low on the list.

Science teaches us that the answer most likely to be correct is one that will not flatter two-legged semi-sentient primates.

DA. I believe the influence of number two in your list has been very much under-estimated in considering the influence ancient humans had on the environment. It was certainly important in NZ and the vegetation of Australia is often refered to as an Aboriginal artifact. A link I provided on the previous page says as much. I also found one that suggests there is a connection in Northeast USA between an increase in fire and dissappearance of mastodonts:

http://www.nrdc.org/OnEarth/06win/mammoth1.asp

Anyway, we can't get away from the fact that there is a high correlation between the first appearance of humans and the dissappearance of many other species.

Now. Back to how did humans get through the ice that covered Northern Canada at the time?