[extropy-chat] Training the immune system

[J. Andrew Rogers]

On May 28, 2006, at 3:44 AM, BillK wrote:
> Sorry, incorrect.  The native Americans were mostly killed by
> smallpox. Though chicken pox and measles also killed many due to
> malnutrition and poor healthcare.  Up to 80% died, by some estimates.
>
> Europeans had little genetic protection against these diseases, as
> shown by the many epidemics in Europe. They did have antibodies
> protection, through childhood exposure, cow pox exposure and primitive
> vaccination-type treatments as smallpox typically killed around 20-40%
> of those infected in Europe.


You are not disagreeing with me.  My point was that if you put two  
populations together in a Metal Cage Death Match with pathogens being  
the weapon of choice, a population that even has a 10% resistance to  
a given pathogen has an enormous advantage.  In the specific case of  
smallpox, virus exposure figures very prominently but it was probably  
not the only reason.

I am thinking of population level interaction, not individual.  Yes,  
many Europeans died from diseases, but that served to concentrate  
disease resistance genes in the population.  In practice, many of  
these mutations generated resistance to diseases to which the  
Europeans had never been exposed e.g. HIV.  There is not  
insignificant evidence of regular catastrophic epidemics due to a  
variety of hemorrhagic fevers and other nasty diseases in Europe.

Again, the more interesting question to me is why the Europeans  
appear to have collected so many disease resistance mutations  
relative to other genomes, and from what I have read and heard from  
researchers there is a noticeable difference in the number of  
resistance markers in European populations versus others.  This may  
be a case of insufficient information about the genome at large, but  
I would not expect disease resistance to be evenly distributed either  
so it makes a reasonable starting point for discussion.  A popular  
theory is that the demographic and cultural specifics of Europe  
encouraged frequent die-offs from disease, but  it is not clear that  
this was a unique characteristic of Europe in the last couple  
thousand years.

The Europeans managed to span the globe and were exposed to a variety  
of diseases, yet I cannot think of a disease they were exposed to  
that they were particularly susceptible to compared to other  
populations.  There are a number of infectious diseases that have  
significant asymmetries in their effect on some ethnic groups, but  
the Europeans seemed to fare pretty well despite a rich set of  
exposures to diseases outside their experience.  The populations they  
interacted with often did far worse when exposed to European  
diseases.  (Parts of this may also have had something to do with  
differences in medical protocol between populations.)


J. Andrew Rogers