Brian Villmoare (Anthropology) published an analysis of ancient footprint sites, focusing on the 1.5 million-year-old footprints from Ileret, Kenya. He analyzed the footprints to determine the relative sizes of males and females, to determine when humans made the transition from a single-male, multi-female society to the more pair-bonded societies we see in humans today. The study revealed that earlier Australopithecus, from Laetoli, Tanzania at more than 3 million years old, was more like gorillas, with large males and smaller females, indicating a polygynous society. But by 1.5 million years ago, humans had transitioned to the size differences we see today. This indicates that Homo erectus was likely to have adopted pair-bonding, establishing the trajectory we see in modern humans. Villmoare participated in the excavation of the footprints in 2012. The study was titled "Sexual Dimorphism in Homo erectus Inferred from 1.5 Ma Footprints near Ileret, Kenya" and published in the May 22 Scientific Reports.