The Evolution Of Mammals Was Tracked By The Composition Of Their Milk
A comparison of human milk and some mammalian species allowed scientists to suggest that its composition may have changed as the structure of the brain became more complex. The study was published by the scientific journal BMC Evolutionary Biology, the press service of the SKOLKOVO Institute of science and technology writes briefly about it.
"There are differences not only between the milk of primates and cows, which is quite expected but also between the milk of humans and monkeys. This means that breast milk is also evolving, and its composition reflects changes in the needs of the body, including the growing brain," said Alexandra Mitina, the first author of the study.
All the nutrients that are needed for growth and development, baby mammals take from their mother's milk. Depending on the habitat and physiological needs, its composition differs from one animal to another. It also changes as the cubs mature.
Breast milk consists of proteins, dry and mineral substances, lactose, and fat (also called lipids). The latter is used by the young not only as a source of energy but also as structural components of cell membranes. This is especially important when forming the brain. Thus, the evolution of milk composition may run parallel to the evolution of the brain, and interspecies differences in mammalian milk are of particular interest to scientists.
Guided by this idea, scientists at the SKOLKOVO Institute of science and technology, led by Philip Haitovich, analyzed lipids from the milk of humans, two types of macaques, cows, pigs, goats, and yaks, and compared its composition for 472 individual components.
The results showed that human milk, unlike the milk of monkeys, contains a large amount of polyunsaturated fatty acids, which play an important role in the functioning of the nervous system. Given that the lactation period in primates and humans is quite long, these differences in a composition may be related to adaptation to the needs of the growing brain, scientists believe.
In future studies, experts plan to compare interspecies differences in the composition of milk with differences in the composition of the brain, concluded Alexandra Mitina.