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