Human evolution: our heart differs from great ape's (Introduction)

by David Turell , Friday, June 14, 2024, 18:09 (160 days ago) @ David Turell

Different left ventricle:

https://phys.org/news/2024-06-architecture-heart-human-evolution.html

"During these great apes' routine veterinary procedures, the team used echocardiography—a cardiac ultrasound—to produce images of the left ventricle, the chamber of the heart that pumps blood around the body. Within the non-human great ape's left ventricle, bundles of muscle extend into the chamber, called trabeculations.

"Bryony Curry, a Ph.D. student in the School of Health and Exercise Sciences at UBCO, said, "The left ventricle of a healthy human is relatively smooth, with predominantly compact muscle compared to the more trabeculated, mesh-like network in the non-human great apes.

"'The difference is most pronounced at the apex, the bottom of the heart, where we found approximately four times the trabeculation in non-human great apes compared to humans."

***

"Curry said, "We found that the degree of trabeculation in the heart was related to the amount of deformation, rotation and twist. In other words, in humans, who have the least trabeculation, we observed comparatively greater cardiac function. This finding supports our hypothesis that the human heart may have evolved away from the structure of other non-human great apes to meet the higher demands of humans' unique ecological niche."

"A human's larger brain and greater physical activity compared to other great apes can also be linked to higher metabolic demand, which requires a heart that can pump a greater volume of blood to the body.

"Similarly, higher blood flow contributes to humans' ability to cool down, as blood vessels close to the skin dilate—observed as flushing of the skin—and lose heat to the air.

***

"'hat remains unclear is how the more trabeculated hearts of non-human great apes may be adaptive to their own ecological niches. Perhaps it's a remaining structure of the ancestral heart, though, in nature, form most often serves a function.'"

Comment: we were different in design from the beginning. Our heart was built to meet the demands of high-speed running.