Why mention sanitation so prominently? Because it is the first survival lesson taught to children.
Also, it is one of the most important.
According to Desmond Morris, the change from living in trees where sanitation was not very
important to living in shelters where sanitation was important, has been very critical to human
evolution. His argument was that humans lost most of their hairiness as a response to the problem
of fleas in homes.
In any case, good sanitary practices are important to human survival and likely to become more so
as population density increases. While a major point of this book is that we will need better genetic
based immune systems, we will have to fight disease in every way we can including immunization and
improved sanitary practices. My guess is that at times when the population is high, people in urban
social settings are sometimes going to have to utilize extreme sanitary practices. Already
there are some fairly strict common rules for food handlers to prevent the very real dangers of
spreading hepatitis, tuberculosis, E coli and a plethora of other common diseases.
The human and financial cost of disease is going to be incalculable. If some theories are correct,
we may not survive it. That is the challenge and was where this book started. It doesn't look like
a great problem right now because antibiotics are still fairly new and effective. That is changing
rapidly and the writing is clear on the wall. The historic diseases are already reappearing and
they are already stronger than they have historically been. Luckily humans have lived in cities
long enough that they have already developed improved immune systems, but we will need better.
This is one of the two overwhelming reasons to use artificial selection.
Parents and social institutions will need to carefully teach children and adults to use what
sanitary practices are available and necessary. It is likely, though I hope not, that
this is something that is going to greatly shape the society. Even AIDS has not done that yet.
Eventually, the most dangerous diseases may be the ones that attack the immune system itself.