Tasmanian Site Discovery

[Rokcet Scientist]

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

Yaba daba dooo!!
They walked!

It is believed that the island was joined to the mainland of Australia until the end of the last glacial period approximately 10,000 years ago.

Told ya!

[Digit]

TASMANIA! The northern bit's called ASIA!!

Roy.

[Minimalist]

Hey, Ish. That's lumped in with #3, "reasons for moving......" Certainly climate change would be a factor which is capable of putting the survival of the group in jeopardy. Climate change occurs slowly though (too slowly to influence human migration?) but a single season of drought might be enough for a group leader to think that it was time to move. Close enough.

The issue is why do people move. Whether they started in Asia or Africa I don't think they did it for shits and giggles. They had a reason which was related to their own survival.



Dig, that would answer part of the question for Tasmania....if not for Australia itself which was certainly never connected to Asia. But the larger question remains. Why migrate?

[Ishtar]

Min, I think an Ice Age may occur quicker than you think. This was from Cogs on my forum a few weeks ago:

Actually, the ice age "climate switch" can occur in as little as three years. However, frigid conditions will take decades to really mess up the neighborhood with accumulated snow turned to ice, etc. Those Pleistocene humans who did not trek south were trapped and isolated in areas where survival was difficult for the most part. A good example of ice age conditions promoting human mutational variability would be the Caucasus region during the Last Glacial Maximum. Almost half of the world's current mtDNA haplogroups originate from that Refugia alone.

From Is Evolution for Homo Sapiens Dead?

And if it's caused by an airburst of some kind (such as hypothesised for the Younger Dryas c.12,000 BC) or as in the above example of an ice damn melting and flooding the seas, climate change can occur a lot more quickly.

[Digit]

For me Min the answer is as I said. Homo perambulus!
I can think of no other driver that would have lasted for thousands of years.

Roy.

[kbs2244]

You know,

All our ice age study and information is concentrated on the Northern Hemisphere.

This site is advertised as the “Southernmost” human site.
(Even though the south tip of New Zealand is a bit further South.)

What, if anything, do we know about the extent of, timing of, and effects of, ice ages and associated climate changes in the Southern Hemisphere?

How much different was Australia in that time period?

Today that continent is pretty “empty” except around the edges.
It is mostly desert.

[Digit]

In some repects Oz has, and has had for many years one of the most extreme climates in the world as regards its variability.
It has periods of modest rainfall followed by periods of extreme drought that are not replicated on any other continent.
This is mainly due to geography. Oz is the only large land mass that is lower in its centre than around its edges.

Roy.

[Rokcet Scientist]

Why do people migrate? Pro-actively for food, shelter, and sex. In that order. Re-actively to escape (a) threat(s)/pressure(s).

[Digit]

Can't see how that would apply to thirty-ish people in one million hectares of mountain, forest, coast, river, and lakes.

Roy.

[Minimalist]

See, that's my problem. Why would they voluntarily leave an area that was meeting their needs? Could a small group really deplete an environment and force themselves into a 'move or die' situation?

And even ish's example about rapid climate change isn't rapid enough. We're assuming an HG type of living. There is no planning for the future in any real sense. Every day its kind of like when my kids were young. They'd stare into the refrigerator and wonder what nature had provided? But a couple of years would be an eternity for an HG group. They would be impacted by a single season without rain. One could fall back on the old 'following-the-animals' adage but that only goes so far. Animals didn't cross the sea. They might not even cross a large river. But man did.

[Digit]

See, that's my problem. Why would they voluntarily leave an area that was meeting their needs? Could a small group really deplete an environment and force themselves into a 'move or die' situation?

Which, Min, seems to leave only my suggestion. After all, with no permanent base nor a need for one, why stay in the one place?
Nothing else seems to fit but an inate desire to wander. The same drive that will one day send us back to the Moon and out from there, we are made that way.

Roy.

[Minimalist]

I guess my view of human nature is fundamentally different from yours.

I think of people as primarily lazy.

And I doubt that has changed in 60,000 years.

[Digit]

I think of people as primarily lazy.

So how did it take just 150 yrs for the US to reach from coast to coast Min?
The lazy ones stay home and hope things will get better, what drove men like your early settlers to move west, passage in a wagon train couldn't have been cheap so they must have given up a lot.
We have colonised this entire planet Min, and we did it before population pressures forced us onwards. Take your Channel Islands, they were occupied almost as soon as man reached the Americas, and they were too far from the mainland for wading to, so why cross the waters when the whole of the continent was available?
Why have some people dedicated their lives to space travel?
All these events are, IMO, a reflection of our innate desire to explore.
The movement of people from Asia into Alaska 'following the herds' I suspect is wrong, by the time the white man reached your country the Bison had a well defined migration pattern, they didn't suddenly head for Cocpacabana once the land bridge formed, and I see no reason to assume that Mammoth etc changed their migration pattern simply because an ice free path cleared between the two continents.
In fact, as far I am aware, the only major migration was human.
I rest my case!

Roy.

[Minimalist]

So how did it take just 150 yrs for the US to reach from coast to coast Min?

Greed.

[Rokcet Scientist]

See, that's my problem. Why would they voluntarily leave an area that was meeting their needs? Could a small group really deplete an environment and force themselves into a 'move or die' situation?

The Mayas (most moved), the Rapa Nuians (most died), and the Khmer (most moved) did it! Among countless others.

And even ish's example about rapid climate change isn't rapid enough. We're assuming an HG type of living. There is no planning for the future in any real sense. Every day its kind of like when my kids were young. They'd stare into the refrigerator and wonder what nature had provided? But a couple of years would be an eternity for an HG group. They would be impacted by a single season without rain. One could fall back on the old 'following-the-animals' adage but that only goes so far. Animals didn't cross the sea. They might not even cross a large river. But man did.

Animals cross rivers and lakes – and, yes, seas – all the time. How about seasonal treks/migrations of land-based animals? Take for instance a couple million wildebeest. Everybody knows the scene where they stampede across a wild river that's infested with hungry crocs!
Yet they do it twice a year, every year. Have done for millennia.
One Zimbabwe elephant herd swims many miles to islands in the middle of a very large lake, and back. Every year, when some particular kind of fruit trees on those islands are ripe, afaik.
Amazonian fire ants hook up, literally, in the hundreds to form floating rafts to cross rivers and lakes. Etc. etc.