One of the more tangible problems for Bible-literalist creationism is that the rocks beneath our feet contain evidence of creatures that lived and died long before the supposed biblical “Creation Week”. Fossilised bones can sometimes appear remote and abstract, but footprints are different. They record a fleeting moment in the life of an individual: a foot pressed into soft mud, weight transferred forwards, toes lifted and another step taken. For a few seconds, an extinct relative of ours occupied that precise spot—and the impression it left can remain for more than a million years.
At GaJi10, on the eastern side of Lake Turkana in northern Kenya, researchers have now documented 21 hominin footprints made by at least eight individuals approximately 1.43 million years ago. The tracks occur alongside those of hippopotamuses, antelopes and other animals that crossed the same muddy lakeshore during the Early Pleistocene. Volcanic ash associated with the surrounding sediments allowed the track-bearing surface to be dated.
As an international research team reports in the Proceedings of the National Academy of Sciences (PNAS), the footprints provide much more than evidence that hominins were present. Their shape and the pattern of movement recorded in them differ from the more modern-looking tracks attributed to contemporary Homo erectus. The researchers therefore consider them most likely to have been made by Paranthropus boisei—an extinct, bipedal cousin of our own lineage, best known from its enormous chewing teeth, powerful jaws and heavily built skull. The attribution is an inference from footprint anatomy and locomotion rather than an identification that can be made with absolute certainty.
