The question of whether our early ancestors walked fully upright or in a crouched position, like apes, has long been a hot debate among scientists.

Now, new research presented at the annual meeting of the American Association of Anatomists during the 2018 Experimental Biology Conference in San Diego suggests that the characteristic bipedalism of modern humans may have evolved much earlier than previously thought—long before our species had even emerged.

For the research, evolutionary anthropologist David Raichlen and his colleagues from the University of Arizona, examined 3.6-million-year-old hominin footprints recently discovered in Laetoli, Tanzania, which represent the earliest direct evidence of hominin bipedalism.

They found that while there may have been some subtle differences, the hominins that made these footprints walked in much the same way as we do.