On December 20, 2024, an intriguing study was published in Current Biology shedding light on the running capabilities of our ancient human ancestors. The research focused on Australopithecus afarensis, a small hominin species that lived over three million years ago. Through advanced 3D computer simulations, scientists were able to create a detailed model of “Lucy,” a famous A. afarensis specimen, and investigate her running abilities.
Led by evolutionary biomechanics researcher Karl Bates from the University of Liverpool and evolutionary anthropologist Herman Pontzer from Duke University, the study revealed fascinating insights into Lucy’s running capabilities. Despite walking upright on two legs like modern humans, Lucy was not built for speed or endurance. The simulations showed that Lucy could only reach a maximum speed of around five meters per second, significantly slower than modern humans who can run at approximately eight meters per second.
One of the key findings of the study was that Lucy lacked the anatomical adaptations that enable modern humans to run long distances. Specifically, Lucy did not have the lengthened Achilles tendon and shortened muscle fibers that are crucial for endurance running. Even when researchers artificially enhanced Lucy’s muscles to mimic those of a modern human, her running performance still fell short.
Further analysis of Lucy’s muscle structure revealed that her energy expenditure during running was comparable to other animals of similar size when she had human-like ankle muscles. However, when her ankle muscles were replaced with ape-like muscles, running became more taxing for Lucy. This suggests that adaptations in the Achilles tendon and surrounding muscles play a significant role in enabling modern humans to sustain prolonged running.
Looking ahead, Bates and his colleagues are planning to investigate how factors such as fatigue and bone strain may have influenced Lucy’s running ability. By delving deeper into the biomechanics of our ancient ancestors, researchers hope to gain a better understanding of how human locomotion evolved over millions of years.
This groundbreaking study not only provides valuable insights into the physical capabilities of Australopithecus afarensis but also highlights the importance of using advanced computational models to study human evolution. By reconstructing the past through cutting-edge technology, scientists are able to unravel the mysteries of our evolutionary history and shed light on the remarkable journey that led to the development of modern humans.
