The authors of this paper note that the footprint sizes indicate that multiple males were walking together in the group, which implies a sense of cooperation and a move away from the sole male dominated hierarchies seen in other primate species. So not only did they have similar walking styles, but similar social styles to contemporary humans.
The big question, though, is what happened to allow such a swift transition from tree-climbing adaptations to efficient walking mechanisms? Some have suggested that the need to use hands for food gathering or tool-wielding prompted the change, whereas others think that it simply requires less energy compared to scampering around on all fours. Perhaps it simply made co-operation easier somehow – either way, it’ll always be difficult to really know what triggered it.
Along with a recent, dramatic re-dating of the revelatory H. naledi fossils, this definitive discovery regarding H. erectus makes it very clear that each new discovery brings with it more questions than answers. Just when we think we know exactly how our species arose from our past, another new piece of information highlights just how much more we’ve got left to understand.
Snap! Credit: Kevin Hatala