milk is pretty amazing
> “…to consider only milk’s nutrient constituents—to imply that it has a single recipe—is to do it “a disservice,” German told me. Mammalian milk is a manifestation of hundreds of millions of years of evolutionary tinkering that have turned it into a diet, and a developmental stimulus, and a conduit for maternal-infant communication, and a passive vaccine. It builds organs, fine-tunes metabolism, and calibrates immunity; it paints some of an infant’s first portraits of its mother, and telegraphs chemical signals to the microbes that live inside the gut. Milk can sustain echidnas that hatch from eggs, and wildebeest that can gallop within hours of birth; it can support newborn honey possums that weigh just three milligrams at birth, and blue-whale calves clocking in at up to 20 tons. Among some primates, it influences infants’ playfulness, and may shape their sleep habits and bias them toward certain foods. Some of its ingredients are found nowhere else in nature; others are indigestible, still others are alive”
[The Atlantic] (https://www.theatlantic.com/science/archive/2023/06/milk-mammalian-evolution-nutrition/674487/)