Boy Milk vs. Girl Milk
At the grocery store, I can purchase a variety of infant formulas. For example, there are formulas for very low birth weight infants, soy-based formulas for infants with dairy allergies, and low-sodium formulas for infants who need restricted salt intake. But should I be able to buy Boy Formula or Girl Formula? The answer is… maybe. Recent research has shown that in deer, monkeys, and humans, mothers make different milk for sons and daughters. No two mammalian species produce identical milk . This is because for each species, milk synthesis reflects the environment, phylogeny , behavioral care, and developmental needs of the young ( Oftedal and Iverson 1995). In terms of environment, the mother’s diet, the climate, and the community ecology can all be associated with milk composition and volume. Closely related species are more likely to produce similar milks due to shared genes. Behavioral care relates, in part, to how often the infant nurses. Young parked in nests, burrows, dens,