I was recently reading about the Paleo diet. The Paleo diet is supposedly what our ancient ancestors living in caves ate. Leaving aside how “genuine” the modern Paleo diet might be, one argument was that the dietary diseases which kill us now, such as diabetes, heart disease, and cancer, can’t be selected against because they kill us AFTER we reproduce.
I disagree that diseases which kill or cripple us after reproduction can’t be selected again. Humans are more like ants or bees, inherently social, and much of the evolution that went into make us what we are today had to do with maintaining the social order. Why else would such a horrible feeling as embarrassment or shame exist?
If the village chief drops dead of a heart attack at the age of 50, and the village chief over yonder survives another 20 years, which tribe has the advantage? The village being led by the experienced chief might easily wipe out the other village. I read in a paper about the evolution of menopause that grandmothers play a major role in the survival of their grandchildren. Which baby is more likely to survive, the one whose brand new mother is assisted by her experienced mother, or the one whose brand new mother is going it alone, or perhaps with the help of an equally inexperienced friend or sister? In modern society, we don’t typically achieve the height of our careers until our children are nearly grown.
In that hypothetical tribe, the village chief shares substantial genes with most of the village. There is significant selection pressure against his premature heart attack.
The Paleo diet may have some merits. I’m only attacking that particular argument, not the diet itself. My own fad diet based on absolutely no evidence would be approximately equal amounts of carbs, fats, and proteins, but no refined sugar, refined flour, or corn syrup. It’s probably about as effective as any low-carb or low-fat diet out there.