Erik Trinkhaus published a study, along with Hong Shang, in the July issue of the Journal of Archaeological Science on what they consider the earliest evidence of footwear of modern humans. The paper is titled, “Anatomical evidence for the antiquity of human footwear: Tianyuan and Sunghir.” They compared and contrasted the morphology of a couple foot bones of humans to human ancestors to see if they can find the effects of shoe wearing on foot bone anatomy.
Before we get into this, I want you to be aware of a couple things. First, the earliest direct evidence of footwear, and by direct I mean actual artifacts of shoes, that I know of are mostly complete sandals from California that date to 9,000 years ago. Other evidence comes from fossilized footprints. Looking at the effects of footwear on foot bones is indirect.
Second, this is not Trinkhaus’ first attempt at establishing the earliest record of footwear. In 2005, he published, “Anatomical evidence for the antiquity of human footwear use,” in the same journal as this current paper. In that paper he sampled foot bones from humans as old as 100,000 years to 10,000 years. He specifically looked for changes in human foot anatomy.
This earlier paper relied on an assumption that shoe wearing causes phalanges or toe bones to become more delicate, or gracile. In other words, the four smaller toes on each foot of people that walk barefoot, flex to allow better traction. This torsional flexion promotes robusticity and sturdy phalanges. In contrast contrast, supportive footwear, like sandals and tennis shoes, lessen the load and force on the four small toes, thus ‘weakening’ them. I’ve seen it myself, in people from the Caribbean and Africa. Often times these people do not wear shoes, or they wear poor shoes. Their feet are much wider than mine and other shoe wearing people, so are their toes.
In the 2005 paper, Trinkaus looked at the toes of western Eurasian human skeletons from the Middle and Upper Paleolithic. He saw that the anatomy of the foot began to change around as early as 30,000 years ago, becoming more gracile than robust Neandertals and early Homo sapiens.
As you can tell from the title of the current study, the two subjects are Tianyuan and Sungir. The specimen from Tianyuan, Tianyuan 1, was actually published by Hong Shang as well as other authors (link is dead, I know). The Tianyuan 1 specimen is represented by a partial mandible and dentition, limited axial remains, portions of all long bones as well as some hand and foot bones. It was discovered in the Tianyuandong, a.k.a. Tianyuan Cave near Zhoukoudian, China. Radiocarbon dating of faunal remains from the same stratigraphic level indicate the Tianyuan 1 remains are at most 39,000 years old.
Sunghir 1 is also a partial skeleton, but it is not from China. In fact, Sunghir was found in a site on the outskirts of a Russian city called Vladimir. It has also been radiocarbon dated. It is roughly 23,000 years old. The interesting thing about Sunghir 1 is that it was excavated with an arrangements of beads sewn onto clothing that was wrapped around the feet — which is interpreted as evidence of footwear.
Trinkhaus and Shang compared Tianyuan 1 and Sunghir 1 foot phalanges to phalanges of archaic humans: Neandertals, humans from the Middle and Upper Paleolithic. They also compared them to foot bones from modern humans: Pueblo Indians, Inuits, and European Americans. The comparison involved the measurement of the cross-sectional area of the phalanges, and looked for the amount of torsion caused by the force of not wearing shoes. This value was coined the polar moment.
The results of the polar moments of area versus the natural log of phalangeal length times body mass is represented to your right. As you can see Tianyuan 1 and Sunghir 1 fall within the range of Inuit and European Americans. But, some European Americans and Inuits also exhibit the same polar moment as Neandertals and archaic humans from the Middle and Upper Paleolithic. Those that do have robust toes could have been non-shoe wearers, they still exist — believe it or not!
If the graph is making your mind spin, check out this photographic array of the Tianyuan 1 and Sunghir 1 phalanges compared to robust, presumably non-shoe wearing human ancestors, Qafzeh 8 and Kiik-Koba 1, a Neandertal. You don’t need fancy pants charts to see how narrow and delicate the Tianyuan 1 and Sunghir 1 bones are compared to Qafzeh 8 and Kiik-Koba 1. But note that bones are not resized to the same scale. Why not?
It is really hard to infer a behavior from one measurement, but I’m pretty convinced. So people were wearing shoes 10,000 years earlier than previously assumed from indirect evidence — definately plausible. People were living in extreme environments for hundreds of thousands of years and needed to protect their feet from the elements!
My most pressing issue is why the bones weren’t adjust to scale in this photo. If they were, we would have a better comparative framework to make the visual assessment ourselves. What if the two TY1 phalanges are longer than the KK1 phalanges? They sure appear to be. If they scaled them down to the length of KK1 phalanges, and the TY1 phalanges appeared to be just as wide as KK1, then Trinkhaus and Shang have a problem. It’s really simple to do. A couple minutes on Photoshop would do the trick. So long as Trinkhaus and Shang provided the normal photo alongside the scaled photo, there would be no worries of manipulation.
TRINKAUS, E., SHANG, H. (2008). Anatomical evidence for the antiquity of human footwear: Tianyuan and Sunghir. Journal of Archaeological Science, 35(7), 1928-1933. DOI: 10.1016/j.jas.2007.12.002
TRINKAUS, E. (2005). Anatomical evidence for the antiquity of human footwear use. Journal of Archaeological Science, 32(10), 1515-1526. DOI: 10.1016/j.jas.2005.04.006