For example, although white potatoes were recorded as being available during the Paleolithic era, they are usually avoided on the Paleo diet because of their high glycemic index. Processed foods are also technically off limits due to an emphasis on fresh foods, but some Paleo diets allow frozen fruits and vegetables because the freezing process preserves most nutrients.
Catching Fire: How Cooking Made Us Human by Richard Wrangham. This book argues that the ease of digestion and the added nutritional value available in cooked food was the key behind the explosion of human intelligence. (Cooking gelatinizes starch, denatures protein, and softens all foods, permitting more complete digestion and energy extraction. As a result, the food processing apparatus shrinks, freeing energy to support a larger brain.) He then suggests that cooking led to what eventually became marriage and the sexual division of labor. The two most helpful reviews at Amazon get into great detail. The reviews average to 4+ stars.
This 2003 CrossFit Journal article captures an early conception of a universal, multi-event test of fitness that laid the foundation for CrossFit competition, including what would become the CrossFit Open and the CrossFit Games. The design requirements for such a test "included but were not limited to the following: quantifiable results; consistency with the CrossFit fitness concept; raising our commitment to improving absolute strength, relative strength, and gymnastic foundations; balancing intrinsic abilities of smaller and larger athletes; emphasizing exercises critical to and foundational to advanced training; mixing training demands within each test and, of course, over the total competition; a design that would identify an athlete’s weaknesses and possibly stand as a workout plan for improving overall fitness; and, finally, we wanted to design a competition that would be 'hard as hell.'"