Human hunter-gatherers, in contrast, typically wean their offspring after three years and become pregnant again long before their little ones are able to feed or fend for themselves, let alone stay out of danger. A typical hunter-gatherer mother, for example, might have a six-month-old infant, a four-year-old child, and an eight-year-old juvenile. Because she is usually capable of gathering only about two thousand calories a day, she cannot get enough food to provide for her own substantial caloric needs, which exceed two thousand calories, as well as the needs of her several offspring, none
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