{"id":131778,"date":"2025-03-14T00:01:34","date_gmt":"2025-03-14T00:01:34","guid":{"rendered":"https:\/\/peraltafinancing.com\/anthropology\/how-well-could-our-early-ancestors-run-a-new-study-puts-australopithecus-afarensis-to-the-test\/"},"modified":"2025-03-14T00:01:34","modified_gmt":"2025-03-14T00:01:34","slug":"how-well-could-our-early-ancestors-run-a-new-study-puts-australopithecus-afarensis-to-the-test","status":"publish","type":"post","link":"https:\/\/fivemor.com\/?p=131778","title":{"rendered":"How Well Could Our Early Ancestors Run? A New Study Puts Australopithecus afarensis to the Test"},"content":{"rendered":"


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Three million years ago on the East African plains, a tense scene might have played out. A group of <\/span>Australopithecus afarensis<\/em>\u2014small, upright-walking hominins\u2014gathers around a carcass, quickly slicing off scraps of meat with sharpened stones. Their actions do not go unnoticed. From the tall grass, a <\/span>Homotherium<\/em>\u2014a scimitar-toothed cat\u2014lurks, poised to charge. The hominins scatter. But could they actually outrun the predator?<\/span><\/p>\n

A new study, published in <\/span>Current Biology<\/span><\/em>, has modeled how <\/span>Australopithecus afarensis<\/em> ran, offering the most detailed analysis yet of their locomotor abilities. The findings suggest that, while they were competent bipeds, their running capabilities lagged far behind those of later human ancestors.<\/span><\/p>\n

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“Our simulations revealed that Lucy wasn\u2019t as efficient or as fast at running as modern humans,”<\/strong> the researchers explain.<\/span><\/p>\n<\/blockquote>\n

While humans today can sprint at speeds exceeding 20 mph, the best <\/span>A. afarensis<\/em> could likely manage was around 11 mph\u2014barely enough to escape a determined predator.<\/span><\/p>\n

To test <\/span>Australopithecus afarensis<\/em>\u2019 running ability, researchers digitally reconstructed the skeleton of Lucy, the most famous representative of the species. Where bones were missing, they used scaled versions of other <\/span>Australopithecus<\/em> fossils. They also incorporated comparative data from chimpanzees and modern humans to estimate muscle placement and function.<\/span><\/p>\n

Using 3D modeling software, they then “fleshed out” the skeleton with muscles, simulating different configurations\u2014from a more human-like anatomy to a more ape-like one. Finally, they tested multiple versions of <\/span>A. afarensis<\/em> with and without an Achilles tendon, a key structure that aids in running efficiency in modern humans but is absent in chimpanzees.<\/span><\/p>\n

The digital models were then placed into a physics-based simulation program called GaitSym, which allowed researchers to simulate running motion, measure energy efficiency, and determine top running speeds.<\/p>\n

The results painted a clear picture: while <\/span>A. afarensis<\/em> was capable of running, it was neither fast nor efficient. The fastest simulated hominin reached just 11 mph\u2014comparable to a slow jog in modern humans. Even untrained human sprinters can hit speeds of around 17.6 mph.<\/span><\/p>\n

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“The metabolic cost of running in <\/strong>Australopithecus afarensis<\/strong><\/em> was up to three times higher than in modern humans,”<\/strong> the researchers report.<\/span><\/p>\n<\/blockquote>\n

This means that every step took considerably more energy, making sustained running over long distances impractical. The presence or absence of an Achilles tendon also made a significant difference: when removed from the simulation, running efficiency dropped dramatically, reinforcing its importance in later hominin evolution.<\/p>\n

These findings challenge the idea that <\/span>A. afarensis<\/em> could have engaged in endurance hunting, a strategy where early humans chased prey until it collapsed from exhaustion. This technique, seen in some modern hunter-gatherer groups, relies on a combination of efficient cooling (via sweating), a long Achilles tendon, and an energy-efficient gait\u2014traits that appear to have developed later in hominin evolution.<\/span><\/p>\n

If <\/span>A. afarensis<\/em> wasn\u2019t built for endurance running, how did they obtain meat? Cut-marked bones dating to 3.4 million years ago suggest they had access to animal flesh, but whether they hunted or scavenged remains unclear. Given their limited running ability, scavenging\u2014perhaps snatching scraps from a predator\u2019s kill\u2014seems the more likely scenario.<\/span><\/p>\n

As for escaping predators, the data suggests they wouldn\u2019t have been able to outrun a fast-moving threat. Instead, they may have relied on group coordination, vigilance, and possibly taking refuge in trees.<\/p>\n

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“If faced with a predator like a <\/strong>Homotherium<\/strong><\/em>, running away probably wasn\u2019t an option,”<\/strong> the researchers note.<\/span><\/p>\n<\/blockquote>\n

The study highlights a crucial transition in human evolution. While <\/span>Australopithecus afarensis<\/em> had already shifted to full-time bipedalism, they had not yet acquired the long-distance running abilities that characterize later members of the genus <\/span>Homo<\/em>.<\/span><\/p>\n

This shift likely occurred around 2 million years ago with <\/span>Homo erectus<\/em>, whose longer legs, shorter arms, and well-developed Achilles tendon suggest a body built for efficient locomotion. The ability to run farther and faster would have given <\/span>Homo erectus<\/em> a major advantage in acquiring food and avoiding predators.<\/span><\/p>\n

For decades, Lucy has been a symbol of the evolutionary leap toward bipedalism. But this new research reminds us that walking on two legs didn\u2019t immediately translate to efficient running. Instead, human endurance running was likely a gradual adaptation, appearing only with later hominins.<\/p>\n

So, if an <\/span>Australopithecus afarensis<\/em> had been caught in the middle of an ancient savanna chase, the odds were not in their favor. Their best bet? Spot danger early, and climb fast.<\/span><\/p>\n

For those interested in further reading, here are additional studies on early human locomotion:<\/p>\n