During the last ice age, a mutation spread in some human populations. The mutation increased the delivery of milk during breast feeding. The figure depicts the region where the studied population lived (shrub tundra). Credit: the researchers, via PNAS
The last ice age and breast feeding, what is the relationship - short science news

According to a new study, the last ice age could have had an unexpected impact on breast feeding in native Americans. Starting from the study of teeth in archeological populations, scientists discovered that a genetic mutation occurred around 20,000 years ago, during the last ice age, in East Asians and Native Americans. The mutation affected the shape of the teeth but also increases the branching density of mammary ducts in the breasts. The latter change probably increased the efficacy of breast feeding in order to provide more fat and vitamin D to infants that were not receiving enough sunlight. The genetic mutation could have spread in the population trough natural selection.

Read the full story: University of California, Berkeley
Scientific publication: PNAS