Overview
- The PLOS Biology paper released Monday by Oxford and Reading researchers reports that two evolutionary shifts best explain our right‑hand dominance.
- The team analyzed hand use in 2,025 monkeys and apes across 41 species using Bayesian models that account for how species are related.
- Humans no longer looked like outliers once the models included brain size and the intermembral index, a measure comparing arm and leg length that signals bipedal specialization.
- Simulations suggest a mild rightward bias in early bipedal hominins and a stronger bias in Homo species such as erectus and Neanderthals, with Homo floresiensis predicted to show a weaker bias.
- The authors note that why a minority remains left‑handed and how culture reinforces hand use are unresolved questions that now guide follow‑up genetic and developmental studies.