germ theory: Ewald&Cochran
The idea is that certain ilnesses are too frequent to be likely of
genetic cause. Rason: the rates of producing offspring is lower than
that of non-diseased organisms hence extinction.
Thus for ulcers the genetic contribution may be present but only if
orn\ganism is infected with virulent Pylori bacterium.
Extreme: {*filter*}s have about 20% offspring of that of total
population. Hence it's unlikely that it is mainly heredetary. Hence
other possibility, which Ewald & Cochran aslo speculate to be
infectious.
Could also be caused otherwize: psycho-developmental;
neuronedocrinological, etc, etc.
Mental illnes:
schizophrenia: high prevalence; possibly Borna virus.
alzheimers: high prev; possibly Chlamydia Pneumoniae (also speculted
to be involved causally in Cor Heart Dis).
Hope that helps you.
