Cross-Species Milk

Our notions of mother's milk come from what we see, and for most of us the milk we see is cow's milk, a brilliant white liquid. But milk from other species looks quite different—kangaroo milk, for example, is pink. But whatever the hue, breast milk is species-specific; that is, the composition is finely tuned to the particular growth and maturational needs and digestive system of the young of each species.^ ^ For example, cow's milk is higher in volatile fatty acids than human milk, and hum...

 The Paradox of Crying Babies

Crying is the earliest and most compelling of infant signals," writes Ronald Barr, and surely there is no sound on earth more piercing than the cry of an infant. The ability to cry was hard-wired into human babies long ago as a potent signal to get adult attention. Like other primates, human infants needed to be able to send a message of distress to motivate action on the part of someone more able. The same kind of vocal signals are found in Rhesus monkeys, for example, which have very distin...

 Infant Behavior as a Key to Human Behavior

Staring at that skull, I was struck by the fact that this ancient child was somebody's baby long ago. Perhaps she was sick, or maybe he e was accident-prone, or perhaps this baby was some predator's dinner. Standing there, I could picture him or her long ago, I, smiling, laughing, and reaching out to grab a mother's breast. It was the most beautiful thing I had ever seen. From a biological point of view, the Taung child represents a specific stage of development for Australopithecines, our ...