[extropy-chat] Training the immune system

[Martin Striz]

On 5/28/06, J. Andrew Rogers <andrew at ceruleansystems.com> wrote:

> 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.

You already answered your own question.  Evolution cuts both ways.
Overuse of antibiotics concentrates resistant pathogens, while
overabundance of epidemics concentrates resistant hosts.  Something
like a quarter of the European population died in the 1300s due to a
single plague.

>  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.

First, there doesn't seem to be a significant asymmetry between
historical European, Asian and African populations, unless those
populations were isolated.  There did seem to be a significant
asymmetry between Europeans and Native Americans, probably because
they were relatively isolated.  Europe was actively engaged in trade
with the Middle East and Northern Africa, and later the Far East.

> 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.

I don't know that Europeans are more resistant than Asians or
Africans.  If Asians had colonized the Americas, then we might be
talking about them.

Plus, it's more than just genetics.  It's also environmental exposure.

> 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.)

Martin