endnote, 529: "Margaret Mead [...] suggested that the first sign of 'civilization' in human history was not tool use but a 15,000-year-old skeleton that showed signs of having healed from a broken femur. It takes six weeks, she noted, to heal from such an injury; most animals with broken femurs simply die because their companions abandon them; one of the things that makes humans so unusual is precisely that we take care of one another in such situations."
see also Romito 2, a 10,000-year-old burial that demonstrates that a "community of hunter-gatherers [...] took pains to support this individual through infancy and into early adulthood" (14)