>If there is this link between being PTC tasting and non-tasting and how one >tastes those greens, would the instincto interpretation be that the >physiology of tasters is unable to handle PTC (or whatever key part of the >molecule produces the taste) and that they are therefore being protected >from it by getting that horrible taste? No , i am going to try to explain how i see it the existence of an alimentary instinct is the result of the accumulation of experiences over many many generations . who allow a memorised genetic recognition of the food. in other words, for the body to be able to recognise a molecule present in food , it must have encountered this food previously itself or its ancestors,.thru genetic memory . the instincto theory will say that the instinct works only with potential food in their natural state. i don't know what is PTC but if that molecule was not part of a food that could have been or is eaten by us or ancestors, they will be no instinctive response to it ( meaning change in taste in accordance with physiological states) .except to keep us away from ingesting it if it was part of our natural environment but not eaten. In case of a new molecule never encontered before , the body have no means of "recognition" it is lost. The bitterness , in greens will be pleasant or unpleasant depending of the body needs for the food that have this characteristic. With A non food molecule , the taste will not change in one individus no matter what is it's physiological state. It doesn't stop 2 difterents individus to have 2 different experiences with it I used to wonder why i could not enjoy wild greens in the past now i can truely enjoy their strong taste. jean-claude