Investigating Development in Human Evolution: Specificities, Challenges, and Opportunities.

Unlike developmental biologists, paleoanthropologists primarily investigate development using skeletal remains, specifically fossilized and already-formed bones and teeth. Focusing on peri- and/or postnatal growth, they reconstruct development from fragmented "snapshots" of individual trajectories at various ontogenetic stages. These constraints prompt a discussion of what defines development versus growth, and its boundaries in studies of hominin evolution. We explore how paleoanthropologists address the limitations of the fossil record by using diverse methodological and theoretical frameworks to identify developmental markers despite missing data. Finally, we discuss the potential of the "Extended Evolutionary Synthesis," which calls for a greater focus on developmental processes in interpreting phenotypic variation in the fossil record.