Sunday, January 20, 2008

The King of Spades Part III, Isolation



ISOLATION


It wasn't long after discussing the dynamics of hare populations and how much of the same characteristics were displayed during the Black Plague in Europe, when Kentar provided a link to the Paul Chefurka site. This can be found at http://www.paulchefurka.ca/Population.html . This is a popular model assuming zero population growth,(the best case scenario),and how the die-off could occur. Most readers over at BNB who were following the conversation, were just horrified! Kentar and I tried to lighten up the mood by joking in effect to obtain zero population growth, would be like asking people to quit having sex... Of course this isn't entirely true, as when deaths exceed births, that is zero population growth. When is that likely to occur? I don't really have an answer to that but, if I had to guess, within the next five years.


It was at this point in the conversation, that I began wondering if I wanted to continue describing what I thought might happen if the lights went out for good, scenario. Of course, the Paul Chefurka site irritated some people, and there were a lot of people who simply weren't posting much beyond this point. This conversation again, can be found in the archives of February and March. I suspect for most, they were too scared to join in the conversation that Sharon, yooper, Kentar and whatmeworry were having. That it was perhaps better to be,"quietly listening"......


Somehow, the conversation turned to thoughts of extinction. I had some definite thoughts about this, as most of the instructors back at the old school house shared this common view, that this "Modern Man" would eventually become extinct.


Perhaps, the most misunderstood aspect of the extinction process and of population dynamics in general, is the effect that isolation has upon it. This is what makes,"island studies" so interesting. Information gathered from such studies is fairly new, within the last fifty years. However, the effects of isolation determine almost all extinctions. I'll use the sharp-tailed grouse here in Michigan as an example to illustrate this concept. Before the massive deforestation of the Michigan, Wisconsin and Minnesota in the late 1800's and early 1900's they were no sharp-tailed grouse in the State. The Sharp-tailed grouse preferred habitat is the grasslands habitat that is found in the western part of the Nation, there it is indigenous and has been for perhaps thousands of years. Once this corridor of now open land and preferable habitat was created, the birds flourish and spread eastward into Michigan. Now, 100 years later these birds will likely become extinct within the next 50 years, according to the Michigan Department of Natural Resources. This diagnosis came after the realization that the birds have become isolated from the indigenous habitat out west. Therefore the distance between suitable habitats,(isolation) is too great for the birds to interact. Sharp-tailed grouse is now extinct in Wisconsin and the ones remaining in the last grassland habitat in Michigan are now trapped from the populations out west. Furthermore, even the distances where sharp-tails exist in Michigan, have become isolated from each other, due to forestation. Even if habitat could be maintained to support a number of birds, they'd likely die out eventually from effects due to interbreeding. So, if a species becomes isolated and cannot impregnate another suitable habitat, the extinction process begins, if that specie cannot adapt to the invading environment. Sharp-tailed grouse are an example of a specie that does not adapt well.
White-tailed deer on the other hand are quite adaptable. Back in the late 1980's, I was privileged enough to obtain a permit to hunt deer on North Manitou Island, Michigan. This is a hunt put on by the MDNR and what's called a primitive hunt, that is what you pack in, you must pack out.. North Manitou Island is 7 3/4 miles long by 4 1/4 miles wide and is located almost in the northern middle part of Lake Michigan. Back in 1926 four male and five female deer were introduced to the island in hopes they would multiply enough to a number large enough for hunting. By 1981, there were an estimated 2,000 deer on the island! The population is now controlled by the hunts, however, not until the deer on the island had mutated to half the size of the deer on the main land! If this population was permitted to go unchecked, I'm sure the deer herd would became extinct in some unimaginable way. This is supported by other island introductions of species, time and again.
The instructors view of isolation was a very unique one. They viewed modern man as a weaker specie from earlier ones, and the more that we strayed from a sustainable environment, the weaker man would become. Furthermore, man already in a physical state of decline could find the distance to a suitable habitat, too great to penetrate. The distance to suitable habitats would become greater, as those habitats grew smaller. When contemplating distance often time is involved. They thought that man already in a weakened state would not have enough resource to make the transition to another suitable habitat in time. If it took X amount of time and unlimited resource to get where we are today and for the population to build as it has, is it reasonable to expect the population to unfold in the same amount of time as resource depletes?

4 comments:

yooper said...
This comment has been removed by the author.
Ed-M said...

Modern man may go extinct, but primitive man will survive... so long as the nukes aren't used.

Anonymous said...

I found this site using [url=http://google.com]google.com[/url] And i want to thank you for your work. You have done really very good site. Great work, great site! Thank you!

Sorry for offtopic

yooper said...

Thanks Anonymous! I've really went back to reflect and report what I learned almost 40 years ago. Much of it is as true today as it was back then...I'm glad you like it!

Thanks, yooper