Breasts come in different shapes and sizes. But there’s one thing they all have in common. They are unique to humans. More than 5,000 mammalian species inhabit this planet. Yet, Homo sapiens are the only life forms with permanent breasts. Some may call this human anomaly sexy. But it also begs the question: Why are human breasts so big and were they an evolutionary mistake?
Every other mammal develops temporary breasts during ovulation and/or nursing. Basically, their purpose is to produce milk. So once the milk is gone, the breasts disappear. But this isn’t the case for female humans whose breasts form during puberty, not pregnancy. So at some point in our evolution, something changed … why? For example, in 1987 biologist Tim Caro explored seven existing theories on this subject. One was that breasts allowed newborns to nurse from the hip, giving their mothers more mobility to multitask. But it doesn’t explain why breasts stick around after the nursing stage is over.