martin schiller wrote:
>
>Reducing infant mortality rates in western culture has been at the
>expense of fitness for all of the reasons that you've been arguing.
iirc from the demography lit., the survival of the first year of life is critical, then the survival to childbearing age is more or less set.
>
>Bottle feeding simply removes the exposure to some transmission of
>specific antigens.
no, what bottle feeding does not provide is the protection that the antibodies in mothers milk do - so-called passive immunity. It's like a shot of gamma globulin (what you used to get for Hepatitis A protection before there was a Hepatitis A vaccine). newborn babies cannot produce antibodies, but their gastrointestinal physiology allows the antibodies in mother's milk to pass into the bloodstream, and this provides a measure of protection against infection until their own immune systems develop to produce their own antibodies.
Anita