For a long time, I have been saying that the Laetoli footprints provide evidence that humans like us existed over three million years ago. New scientific research on the prints supports this conclusion of mine. Let us first look at the history of the Laetoli discoveries. Then I will summarize the latest research and analyze what it means.
In 1979, a team led by Mary Leakey was doing archaeological research at Laetoli, in the East African nation of Tanzania, about 30 miles north of Olduvai Gorge. One day, several members of the team were playing around, throwing pieces of dry elephant dung at each other. Andrew Hill, of the Kenya National Museum, noticed some marks on the ground. They turned out to be fossil footprints. Some of them looked humanlike. The prints were found in layers of solidified volcanic ash. Potassium-dating yielded an age of at least 3.6 million years for these ash deposits (tuffs). So 3.6 million years ago, someone with humanlike feet was walking around in Africa.
But how humanlike were the footprints? A report by Mary Leakey appeared in National Geographic magazine (“Footprints in the Ashes of Time,” 1979, vol. 155, pp. 446-457). About the creature that made the footprints, Mary Leakey said “the form of his foot was exactly like ours” (p. 453). Dr. Louise Robbins, a footprint expert from the University of North Carolina, was part of Leakey’s team. In the National Geographic report (p. 452), Robbins is quoted as saying about the footprints: “They looked so human, so modern, to be found in tuffs so old.” The British physical anthropologist M. H. Day carefully studied the prints. One of his reports (“Hominid locomotion—from Taung to the Laetoli footprints”) was published in the book Hominid Evolution: Past, Present, and Future (edited by P. V. Tobias, 1985, pp. 115-128). In this report, Day said that the Laetoli footprints “showed close similarities with the anatomy of the feet of the modern human habitually unshod, arguably the normal human condition” (p. 121). Physical anthropologist R. H. Tuttle said in one of his studies (“Evolution of hominid bipedalism,” Philosophical Transactions of the Royal Society of London, B, 292, pp. 89-94): “The shapes of the prints are indistinguishable from those of striding, habitually barefoot humans.” Finally, paleontologist Time White is quoted in the book Lucy (D. C. Johanson and M. A. Edey, 1981, p. 250) as saying this about the Laetoli footprints: “Make no mistake about it. They are like modern human footprints. If one were left in the sand of a California beach today and a four-year-old were asked what it was, he would instantly say that somebody had walked there. He wouldn’t be able to tell it from a hundred other prints on the beach, nor would you. The external morphology is the same.”
So the shape of the footprints is exactly like that of modern human beings. But what about the gait? Recently, a group of scientists headed by David A. Raichlen, of the department of anthropology at the University of Arizona (Tucson campus), published a study in the online science journal PLoS ONE (10.1371/journal.pone.0009769). The study deals specifically with what the Laetoli footprints say about the gait of the creatures that made them. Is the gait like that of modern human beings (upright striding) or more like that of chimpanzees (bent knees, shuffling)? To determine the answer, the researchers had humans walk barefoot across a bed of sand (prepared to resemble the Laetoli sediments). Some of them walked as humans normally do. Some of them walked with bent knees, like chimps. All the features of the resulting prints were carefully measured, especially the depth of the prints. The researchers then compared the results with the Laetoli prints, which many scientists attribute to the apeman Australopithecus afarensis. David Raichlen said, “Based on previous analyses of the skeletons of Australopithecus afarensis, we expected that the Laetoli footprints would resemble those of someone walking with a bent knee, bent hip gait typical of chimpanzees, and not the striding gait normally used by modern humans. But to our surprise, the Laetoli footprints fall completely within the range of normal human footprints” (retrieved March 23, 2010 from ).
So what do we have here? We have evidence that the Laetoli footprints are like those of modern humans, in terms of both their shape and gait. But none of the above mentioned scientists believed that the Laetoli footprints were made by humans like us. Why not? According to their theories, humans like us had not evolved yet. Supporters of the current evolutionary theories of human origins believe that humans like us first came into existence between one hundred and two hundred thousand years ago. Before that, there were (supposedly) only more primitive apelike ancestors of modern humans. So according to these scientists and their colleagues, who actually did make the Laetoli prints? They have various theories. Mary Leakey, for example, believed that the footprints were made by some kind of apeman who had feet exactly like those of modern human beings. That is an interesting idea, but there is no skeletal evidence to support it. We have the skeletons of the apemen who existed at that time, three or four million years ago. And none of them have foot bones like those of modern human beings. Their toes are longer than modern human toes. In particular, the apemen of that time period have long first toes that can extend out to the side, sort of like the thumb of the modern human hand. Altogether, the feet of the apemen from that time (Australopithecus, Ardipithecus, Kenyanthropus, etc.) resemble those of apes. Actually, the only creature known to science today (from skeletal remains) that has a foot exactly like that of a modern human being is, in fact, the modern human species.
But this has not stopped some scientists from speculating how an apeman foot, like that of a chimpanzee, could make footprints that looks like those made by a modern human being. Ron Clarke reported the discovery of a partial Australopithecus foot from the Sterkfontein site in South Africa, and in 1998 he announced the discovery of a fairly complete australopithecine skeleton, to which the foot bones had originally been attached. The toes were quite long and the big toe was especially long and divergent, like that of a chimpanzee, with features indicating it was capable of grasping.
In January 1999, at the World Archeological Congress in Cape Town, South Africa, I saw Clarke attempt to justify how the chimpanzee-like Sterkfontein foot could have made the humanlike Laetoli prints. He suggested that the apemen were walking with their normally divergent big toes pressed inward so as to align with the other toes. These other toes, although longer than human toes, could have been curled under, suggested Clarke. But it is highly unlikely that the three individuals who made the trails of prints at Laetoli would have all been walking like that. Furthermore, no knuckle marks.
In their recent report, Raichlen and his coauthors were honest enough to admit “While our results show that Laetoli hominins walked with humanlike kinematics, we still cannot be sure which hominin taxon made the footprints.” Hominins are the biological group that contains the modern human species and its supposed evolutionary ancestors.
I propose that it was humans like us who made the Laetoli footprints, for the following reasons: (1) the shape of the footprints is identical to the shape of modern human footprints; (2) at present, skeletal remains show that the only creature known to science that has such a foot is a modern human being; (3) the Laetoli footprints show a gait just like that of modern human beings; (4) and finally, there is skeletal evidence for anatomically modern humans existing at roughly the same time that the Laetoli footprints were made, about 3.6 million years ago.
For example, in 1880 the Italian geologist Giuseppe Ragazzoni reported finding anatomically modern human skeletons in a Middle Pliocene formation at Castenedolo, Italy (Commentari dell’ Ateneo di Brescia April 4, pp.120– 128). The Middle Pliocene period goes back to between three and four million years ago. Anatomically modern human bones were also found in a Middle Pliocene formation at Savona, Italy. This was reported to the scientific world at the 1871 meeting of the International Congress of Prehistoric Anthropology and Archeology. In 1965, Bryan Patterson and W. W. Howells found at Kanapoi, Kenya, a humerus (upper arm bone). In their original report (Science, 1997, vol. 156, pp. 64-66), they said its measurements can be duplicated on modern human humeri. The Kanapoi humerus is over four million years old. Of course, as I have shown in my book Forbidden Archeology, there is a lot more evidence showing that humans like us have existed on this planet for tens of millions, even hundreds of millions, of years. The Laetoli footprints, which are fully modern in terms of shape and gait, support this conclusion.
Michael A. Cremo is the author, with Richard Thompson, of the underground classic Forbidden Archeology: The Hidden History of the Human Race. His latest book is Human Devolution: A Vedic Alternative to Darwin’s Theory (see www.humandevolution.com).