> There is no "survival value" in having morning sickness.   What possible
> benefit for mother and baby could be had by mom vomiting up her food or
> being unable to eat at a time when her nutritional needs are greater than
> normal?

Actually I think it does have survival value (I can say this because I am
male and it's easy for me to say ;-))

I have read about a study that showed that women with morning sickness had
more successful pregnancies statistically. I have also read speculation that
morning sickness is a benefit because when the fetus is most vulnerable, the
early stage of pregnancy, morning sickness increases the woman's sensitivity
to potential fetal toxins including those found naturally in food.

--Richard