Pelvis changes linked to upright walking

A study traces two developmental changes in the human ilium that enabled upright walking, using histology, imaging and multiomics to map how regulatory networks shaped pelvis evolution.

The evolution of hominin bipedalism in two steps

A new study identifies two developmental changes in the human ilium that helped make bipedalism possible. Researchers report that the iliac growth plate orientates perpendicularly to that of other primates and that ossification follows a posterior initiation with external cells contributing to osteoblasts. The team compared human fetal samples with mouse and non-human primates using histology, CT imaging, single-cell multiomics and spatial transcriptomics to link these changes to regulatory networks including SOX9, ZNF521, PTH1R, RUNX2 and FOXP1/2.

The results suggest a coordinated shift in cartilage, perichondral tissue and osteoblast formation that allowed the pelvis to grow and form a distinctive ilium in humans. The authors also report evolutionary signals in regulatory elements and HAR enrichment, hinting at how modern human anatomy arose from ancient changes. The work was conducted with ethically sourced fetal tissues, mouse models and advanced computational analyses.

The study shows how modern tools can illuminate a long-ago shift in our anatomy. By weaving together histology, imaging and single-cell genomics, it connects tiny cellular moves to a big effect on how we walk.

Yet the breadth of methods also invites caution. The findings rest on fetal tissues and animal models, plus complex data analyses that require careful interpretation. The work challenges simple narratives of evolution and points to a layered picture where several genetic levers shape a single bone and a crucial trait.

Highlights

The bone story continues as scientists connect ancient steps to modern movement.