Scientists at the Skolkovo Institute of Science and Technology (Skoltech) and German researchers have found that the prevalence and concentration of certain fats in mammalian tissues varies greatly in the course of evolution, with the biggest number of evolution-specific changes occurring in humans.

The new Skoltech campus, to which staff and students are due to move by the new academic year. Photo:

The scientists conducted a large-scale collaborative research project to study the fat composition in six different tissues of 32 mammalian species, and published the results of the study in the Molecular Biology and Evolution scientific journal.

Lipids, which include fats and a few other fat-like substances, perform a variety of important functions in a living organism’s cells, from cell membrane construction to energy storage and, most interestingly, transfer of signals between cells, primarily in the brain.

Skoltech researchers conducted extensive bioinformatics analyses of lipids in the tissues of 32 mammalian species, including humans and other primates, rodents and bats, using tissue samples from the cerebral cortex, kidneys, heart, muscles, liver, and cerebellum. The study revealed a multitude of species-specific changes in the lipid composition, which are observed in record numbers in humans and localized primarily in the brain.

“Interestingly, the human-specific lipids that we found are involved mainly in the metabolic pathways associated with cognitive diseases, such as Alzheimer’s, Parkinson’s, and other nervous system disorders,” says the study’s first author and Skoltech researcher Ekaterina Khrameeva.

“This suggests that these lipids are essential for our cognitive activity, which is exactly what distinguishes our species from others.”

In contrast to the genetic differences between species that are quite well understood, little is known about the evolutionary changes and trends in the lipid composition in different groups of living organisms. Scientists have long assumed that lipids may be able to provide a wealth of knowledge about human brain evolution and bring humankind one step closer to cracking the mystery of the origin of the human species.