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Re: diseases and immunity
Philip Deitiker (pdeitik@bcm.tmc.edu)
Mon, 01 Jul 1996 00:43:08 GMT
Sisial@ix.netcom.com wrote:
>Philip Deitiker wrote:
>My point is that the technology appears neolithic throughout North America. While,
>the hunter-gatherer lifestyle is usually associated with the paleolithic period,
>there were cases in Europe of neolithic hunter-gatherers. The existance of
>neolithic hunter-gatherers in North America then does not come as a surprise. It
>is the technology which identifies the stage of development.
Good style, overthinking the problem of nomenclature, though, I don't
think you've solved the problem just qualified it, hey it works form
me <grin>. A good point in comparison of european HG's with american
HG's. This sets the stage for an argument which I haven't been very
good a presenting so far (since I've seemed to be toe stepping about).
But the issue of comparing europe with america and the population
parameters, which Firl was trying to take a misguided stab at, is: did
the mass of euarasia undergo some genetic selection as a result of the
population/lifestyle dynamics which evolved over the last 12,000 years
and in this regard how does america compare? First off, I agree with
you, I don't think its valid to lump the entirety of north america
into the same basket, and said so several times. I think a major point
of segregation is the means of existance in tropical america differed
significantly compared to the temperate regions. Since SA is mostly
tropical and NA is mostly temperate one has to argue that this might
have affected molecular evolution, the genetic data on suggests
emphatically , yes.
Now, to the comparison. In eurasia there seems to have been the
significant development of a tri-continental culture at the
convergance of those three continents about 12,000 years ago if not
before, this was about the time that 'paleoindians' imigrated into the
new world. From this time forward, if one examines western euarsia and
africa events which occured here radiated outward in effect. The fact
that there where stone-age cultures in europe isn't as important as
the circumstances of the conversion of those cultures as a result of
waves of both immigrants and technologies into the region. Its clear
that up until about 1000 years ago the semetic/mediterranean/black sea
cultures controlled the balance of power in the region and had access
to both cultures in africa and the far east (china) by land. This is
the major tenant, and support for this is the fact that during this
period the population centers derived sources of food distant from the
site of habitataion in many regions. This allowed both a concentration
of individuals and also extended the number of individuals that an
individual or his food had contact with. It clear from the study of
gravesites in the mediterranian that this type of food procurement had
side-effects including disease transmission and famines that promotes
disease. The domestication of animals and the altering of relationship
may have also contributed to the entering and solidification of
pathogens within the human population. Other than the mediterranian
there were population centers in asia, the americas and africa which
deserve some attention. All of these centers had the capacity of
quickly distributing pathogens to other centers once formalized in
that population with the exception of those in the americas.
What did the america's lack which eurasia possesed.
1. Since america was only recently settled by asian colonizes it
probably wasn't until the 9th millenium BC that any significant
population centers developed.
2. At least 2,000 years behind in the domesitication of seeds than the
best of eurasia, (not unexpected if the variety of HG type foods
available without neccesity of agriculture) and several thousand years
behind in the development of animal husbandry. (not unexpected if wild
food stocks are avialable)
3. The development of civilizations comparable with key eurasion
civilizations was of some delay. These centers were surprisingly
advance given the proposed methodology of immigration (which is now a
matter of some debate), which just like euarsia seems to have
initiated in a central region and radiated outward bilaterally in a
temporal manner. But the issue here is not as much on developement as
critical contacts. To what extent did mesoamericans have contact with
peripheral cultures. In south american the answer seems to be
extensive and emcompasing, but with a few examples of repulsion from
non-participatory groups. In north america even without considering
the civilization of the northeast other civilizations developed and
were probably focused from the time of immigration to the new world.
Its apparent that in certain regions there was trade such as between
the mainland and the ilses of the carribean, probably upward into the
southwest indirectly. In addition there were power stuggles occuring
between newer groups and older cultures and mobility in this regard
can be considered common. But I would argue that the rate of mobility
between the polar extremeites of america was very restrictive such
that a pathogen required 10-20 generations to go from north to south
or from south to north. Second the carrying populations may have been
so small that nascent epidemics were self contained. Third the
diversity of potential vector-populations (closely related primates,
other large animals, rodents, etc.) was diminished. Thus, Firl is
probably right in saying that populations experienced new pathogens at
a slower rate than in europe. But I argue that in some regions the
lethality of pathogens in non-niave populations was probably
comparable.
4. Because of the long term problem of human civilization (by western
standards), societies began the developemnt of facilities for dealing
with waste and disease. Myself, having developed similar facilties
basically from scrath for aquatic animals can testify to a major
problem in doing this. Each solution for each problem is followed by
another problem which needs solving. Nature is unstopable in its
ability to redicule the best technologies and really defies the growth
of more than a percentage of filial to the next generation (i.e.
survival of the fitest is probably natures way of establishing a
workable equilibrium population):
One builds a filter for the detoxification of ammonia. The
detoxification of ammonia leads to nitrate and acidification. The
acidifcaition problem can be dealt with by adding a alkali reservoir
such as porous calcium carbonate. This boost the pH but unfortuanately
anearobic pathogens are stimulated because they prefer neutral pH, the
problem of dissolved organics in the water are not significantly
reduce by the aerobic filter and food wastes which acculumate provide
a base for expansion. The solution to this problem is adding a defined
digestion filter for bacteria allowing both the correction of of DOC
levels and denitrification to correct pH. The anoxic filter is
sensitive to medications so treatment of parasitic diseases has to be
done carefully.........and so on.
The point is that each implimented technology allows a burst in
population until its side effect equilibrates. So its not unexpected
to see burst and die-offs even in moderately sophisticated
populations; however, if one rips away the technology (as I have done
to some aspects of the above scenario) the population may stabilize
then really drop. This is not to argue that pre-columbian amerinds
did not work through some of the issues of overpopulation, I'm sure
they did but had they done this either genetically of technologically
to the extent that europeans did, for it was not europeans which were
being forced into american culture it was amerinds being forced into
europeans and contact with diseases which had equilibrated in the
european populations. Again just to state that in this each new
disease also becomes a parameter in the equilibrium equation. Polio
for example was dealt with by a vaccination, which itself has a
disease rate, prior to this the sophisitcation of european plumbing
was not sufficient (and still isn't) to exclude all fecal/oral
contamination. It does seem sufficient for diseases like typhus, and
other diseases.
But the issue is whether or not there is a choice. For example,
europeans having restled with bubonic paque for several hundred years
did not resolved to go 'native' (i.e. hunt-gath), but focused on
targeting (albeit erroneously) the source of the problem. The amerinds
in the north probably used a strategy of rotation, rotating back and
forth to regions when an old region was too contaminated to live in
anymore, (in aquatic culture this is simulated by major changes in
water and manually cleaning or replacing old media) systematized
rotation is clearly evident in 'neolithic' cultures in south america,
whereby the nutrients in the rain forest soil are insufficient to
support continuous agriculture, and the plains indians undertook a
strategy of following prey herds leting the herds select the best
areas. Unfortunately rotation becomes problematic when a new culture
intercedes ones ability to move by imposing more static structures.
The other choice is to reduce or spread the population so that
pathogen density drops to inocuous levels and eventually stays only in
the vector population. (Same solution as in europe, also not taken in
america)
The modern answer is to use natural processes such as assisted
bioremediation to more efficinently and less stocastically deal with
the products of overpopulation as far as waste and other contaminants
are concerned. For other types of infectious diseases intervention is
best implemented prior to disease presentiation and illimination of
disease from a population prior to transmission. This had been almost
accomplished with most chronic communicable diseases until the last 20
years when intercontinental travel reached the high levels permitting
the reintroduction of TB etc. Thus as I have said before, unless
samples were taken and preserved, its really very difficult to
determine a precise scenario as to why an ancient epidemic was more or
less destructive to a population, only that the growth in population
is bound to force such epidemics as a result increasing the rates and
the severity of epidemic when it occurs. Again from a molecular
genetic point of veiw what types of changes are documented, I think
there is sufficient evidence that over the last 11,000 years new
epidemics seem to have resulted in microevolution from groups moving
from temperate to tropical regions. But where there significant
changes which occured from the differential progress in the temperate
new world vs. temperate old world. On this issue its has been
presented that there was differential immunity to certain diseases. I
pose the hypothesis that its near impossible to separate the genetic
arguments and enviromental parameters which contributed to the rates
of infection and mortality in the population despite some of the high
intial rates of infection and mortality,..... because the
circumstacnes of first contact in europeans and amerinds differed from
one another.
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