The Evolution of Man

[Ngala]

Footprints reveal direct evidence of group behavior and locomotion in Homo erectus Hatala et al, 2016

*This image is copyright of its original author

Figure 1: 1.5 Ma hominin tracks from Ileret, Kenya.
Representative images of hominin tracks uncovered in the Ileret area between 2007 and 2014. These tracks come from five different sites within about 1.5 km of each other. Some tracks show deterioration and overprinting, while many preserve fine detail, indicating that they were rapidly hardened and covered with sediment. No two sites represent the same continuous surface, as all come from different stratigraphic levels within the Ileret tuff complex. The total sample includes 97 hominin tracks produced by at least 20 different individuals.

Abstract:
"Bipedalism is a defining feature of the human lineage. Despite evidence that walking on two feet dates back 6–7 Ma, reconstructing hominin gait evolution is complicated by a sparse fossil record and challenges in inferring biomechanical patterns from isolated and fragmentary bones. Similarly, patterns of social behavior that distinguish modern humans from other living primates likely played significant roles in our evolution, but it is exceedingly difficult to understand the social behaviors of fossil hominins directly from fossil data. Footprints preserve direct records of gait biomechanics and behavior but they have been rare in the early human fossil record. Here we present analyses of an unprecedented discovery of 1.5-million-year-old footprint assemblages, produced by 20+ Homo erectus individuals. These footprints provide the oldest direct evidence for modern human-like weight transfer and confirm the presence of an energy-saving longitudinally arched foot in H. erectus. Further, print size analyses suggest that these H. erectus individuals lived and moved in cooperative multi-male groups, offering direct evidence consistent with human-like social behaviors in H. erectus." Reply