Overview
- The study, published in Science Advances in September 2026, used CT scans of bone shafts to measure cross‑sectional strength, which records habitual loading from activity over an individual’s life.
- Analyses of the 3.67‑million‑year‑old Little Foot skeleton show relatively strong arms like African apes and more humanlike lower‑leg signals, indicating a mixed lifestyle of frequent climbing plus bipedal walking.
- An early Homo individual from Dmanisi, dated to about 1.8 million years ago, displays limb‑strength proportions squarely within the modern human range, matching similar signals seen in Homo erectus fossils.
- The authors interpret the consistent pattern in early Homo as evidence of a behavioral threshold between Australopithecus and Homo when regular arboreal weight‑bearing was largely abandoned, while stressing that causes remain unresolved.
- Because stone tools predate this shift by over a million years and sample sizes remain small, the team calls for more fossils and contextual data to test links among locomotion, ranging, diet and brain evolution.