Born with the munchies. Naturally-occurring cannabinoids have been detected in human and cow’s milk and their levels are highest the day after giving birth. Their function, and the evolutionary significance of human sensitivity to them and hence to cannabis, has been puzzling. Now, a biologist in Israel reports that the chemicals might be necessary to jumpstart feeding behavior in the newborn; when neonatal mice were treated with a cannabis blocker, they didn’t feed and didn’t survive, but when given enough THC to overcome the blockade, they developed normally. Many of you are not surprised, I suspect, by the notion that cannabis is necessary to survival…