Evolutionarily determined ratios of stearic acid to oleic acid to linoleic acid in fats signal food availability and the need to gain fat.

“these are probably evolutionarily determined ratios of steric acid to OIC acid so saturated 18 carbon monounsaturated 18 carbon to polyunsaturated 18 carbon being l olic acid in this case the ratios there are just evolutionary signals to humans to say hey somehow you wandered up into British Columbia and you need to get fat right now or the animals are eating more polyunsaturated fat or there are some egg horns over here that have more monounsaturated fat you you just monounsaturated fats are more available as you move away from the equator as are polyon saturated fats”