Longevity and brain size explain our “gorilla aorta”

Although humans weigh about half that of gorillas, the size of our aorta – the main artery in vertebrates – is very similar. Today, an international study explains that the development of brain is behind us “gorilla aorta”.

The study, led by the Complutense University of Madrid (UCM) and the University of Valladolid (UVa, center), in which the National Museum of Natural Sciences (MNCN-CSIC) has also participated, was published in the journal ‘Scientific Reports ‘.

The research, in which the University Hospital of Ghent and the University of Oxford also participated, was carried out with data from human echocardiograms, with data from gorillas and chimpanzees from US zoos included within the ‘Great Ape Heart Project’and with hearts and skeletons of great apes from the Anatomical Museum of the University of Valladolid.

The aorta is the vessel through which the blood that the heart pumps during the beat passes, and its diameter is related to cardiac output, the blood pumped per minute for all the metabolic activity of the organism that regulates everything from digestion to physical activity. or body temperature.

“By having a larger aorta per unit of mass, humans would have a higher cardiac output and therefore a higher energy budget per unit of mass than our closest relatives, the great apes”explained Luis Ríos Frutos, a researcher at the UCM Department of Biodiversity, Ecology and Evolution.

In the same work, the researchers conducted a literature review to study cardiac and energy expenditure in a life cycle.

Thus, they observed that in childhood we have higher cardiac output and burn more energy per unit of mass than when we are adults.

“One of the reasons is the growth of our large brain, which is an energetically very expensive process that takes place up to 4-6 years of age; From that age, the cardiac output per unit of mass decreases.explained the UCM researcher. The team also studied cardiac output from an evolutionary perspective.

Due to the flat chest of humans, the large size of the aorta forces it to stick to the spine, leaving marks on the vertebrae.

“Closely related Neanderthals with a large brain and life cycle similar to ours also have aortic imprinting, while an older hominin with a shorter life cycle and smaller brain, such as Homo ergaster, It seems not, according to our hypothesis”pointed out MNCN researcher Antonio Rosas.

From this it can be deduced that, as brain size and longevity increased, greater cardiac output was required, so that, evolutionarily, the size of the aorta also grew.

“Changes in the cardiovascular system must have been fundamental during human evolution”concluded Francisco Pastor, from UVa and leader of the project together with Ríos Frutos.

Source: EFE