Most of us learned about our nutritional food pyramid in school, where we were advised to eat lots of the bottom layer (grains, cereals), slightly less fruits and vegetables, much less meat and fish and only a little of the top of the pyramid, sweets. The food pyramid has recently been replaced with something called the “food plate” which shows what we should be eating in a kind of a pie chart (no pun intended) superimposed on a plate. In biology, the idea of a food pyramid has long bee ...