A research team from Swansea University and UBC Okanagan has found new insights into human evolution by comparing human hearts with those of other great apes. Despite sharing a common ancestor with other great apes, humans evolved larger brains and the ability to walk upright, possibly for hunting.
Using echocardiography to image the left ventricle, researchers compared human hearts to those of chimpanzees, orangutans, gorillas, and bonobos. They found that human left ventricles are smoother with compact muscle, unlike the more trabeculated hearts of great apes.
PhD student Bryony Curry noted that the difference is most noticeable at the heart’s apex, where non-human great apes have four times more trabeculation. The team also measured heart movement using speckle-tracking echocardiography.
Bryony explained that less trabeculation in human hearts is linked to better heart function. This supports the idea that human hearts evolved to meet the higher demands of our unique lifestyle. Humans need a more efficient heart due to their larger brains and excellent physical activity, which require more blood flow. This also helps humans cool down by allowing them to lose heat through the skin.
This study reveals that the unique structure of the human heart, with its smoother left ventricle and better function, evolved to support our larger brains and higher physical activity. These findings offer new insights into human evolution and how our hearts adapted to meet the demands of our lifestyle.
Journal reference:
- Curry, B.A., Drane, A.L., Atencia, R. et al. Left ventricular trabeculation in Hominidae: divergence of the human cardiac phenotype. Communications Biology. DOI: 10.1038/s42003-024-06280-9.