It is just over six months since the publication [1] of the paper proposing the name Homo naledi for the remarkable collection of hominin remains recovered from the Dinaledi Chamber, part of the Rising Star cave system, in the Blauuwbank Valley, South Africa.
The discoveries in the Dinaledi Chamber are unusual for several reasons. First, the only hominin represented in the chamber, H. naledi, is the sole mammal species represented among the more than 1500 bones and teeth recovered. This makes the context of these discoveries very different from that of the early hominin fossils recovered from several well-known cave sites that also formed in the stromatolite-rich dolomite. Second, while the hominin remains extracted from the Dinaledi Chamber sampled at least 15 individuals, the sheer number, completeness, and comprehensive regional representation of the hominin remains recovered means that in the space of two short field seasons Lee Berger’s team have provided the wherewithal to know more about the morphology of H. naledi than we know about other hominin species from southern Africa whose remains were discovered many decades ago. Third, because of this impressively large bolus of information, we know that the bones and teeth of H. naledi show a seemingly perplexing mix of primitive – small brain, curved finger bones, small hip joint – and derived – small and simple tooth crowns, modern human-like wrist and foot – features. Fourth, the geological context of the discoveries is such that, try as they may, at the time of their report the researchers had been unable to generate a reliable estimate of the age of the recovered bones and teeth.
When discussing these important discoveries with the students in my human evolution class, I stress that the age of these, or any other, hominin remains cannot, and should not, influence how the morphology is reported and judged with respect to decisions about taxonomy. But it does not take the students long to realize that the geological age of the remains assigned to H. naledi substantially influences the broader evolutionary implications of that morphology.
I was trying to think of an apt analogy for the students, and then a visit to an art gallery provided one.
In the same week H. naledi was published, I was giving a talk at the University of Pennsylvania in Philadelphia, and I took the opportunity to pay a visit to the newer of the two campuses of The Barnes Foundation, whose history is nearly as complex and byzantine as the contextual history of the bones and teeth found in the Dinaledi chamber. The focus of The Barnes Foundation’s Benjamin Franklin Parkway campus is a fine new building designed by Tod Williams and Billie Tsein Architects. Their design brief was challenging because one of the conditions of being allowed to move Dr. Albert C. Barnes’ art collection from its original home in one of the suburbs to the west of Philadelphia, was that the rooms in his Merion residence had to be replicated precisely, and the paintings and metal-work displayed exactly as they were when Barnes died in 1951.
Albert C. Barnes, who came from a dirt-poor background, went to medical school at the University of Pennsylvania. After qualifying as a doctor he underwent training in physiological chemistry in Germany, and then worked as a consulting chemist in the US before, in 1902, setting up a pharmaceutical manufacturing business with Herman Hille. In 1908 Barnes bought out Hille, founded the A.C. Barnes Company, and made his fortune by developing and marketing a silver-based antiseptic compound called Argyrol. In this pre-antibiotic era, Argyrol was especially effective at curing “sticky eye,” which, if left unchecked, can result in blindness [4]. Unlike many, this physician-cum-pharmaceutical entrepreneur sold his business just before the 1929 crash, survived it and went on to use his considerable fortune to build the art collection you can see today.
Barnes was obsessive about making sure his collection was presented in a way that educated those who visited his galleries, and as he added to his collection he continued to adjust the “ensembles” of paintings and metalwork on each wall of each gallery, juxtaposing paintings from different periods and styles. He was a little too fond of Renoir for my taste, but Barnes’ collection includes some of my favorite paintings by Van Gogh and Cézanne. In Room 2, his pairing of a Cézanne still life with El Greco’s Apparition of the Virgin and Child to Saint Hyacinth caught my eye, and gave me the analogy with H. naledi I was seeking.
Consider this thought experiment. Someone finds a collection of oil paintings in an attic in Paris, and all look as if the same artist painted them. The better-preserved ones seem to show an intriguing mix of painting styles, part El Greco and part Cézanne. But we have no idea how old the paintings are. So are they from the time of El Greco, by an artist with premonitions of Cézanne, or are they from the time of Cézanne by an artist who wanted to pay homage to El Greco? Or were they painted at any time between the two artists?
Whatever their age turns out to be, is this collection of paintings important from the point of view of the history of art? It surely is. Does the collection change our current understanding of the history of art? No.
My sense is that much the same can be said for H. naledi. I have a not insignificant bet with a colleague that the remains assigned to H. naledi are less than half a million years old. My best guess is that H. naledi represents a local relict population with a combination of characters that does not reflect the way these characters were accumulated during human evolutionary history.
Now I need to get back to training and educating the students who will help determine whether I am right, or not.
--
1 Berger et al. eLife 2015;4:e09560. DOI: 10.7554/eLife.09560
2 http://www.barnesfoundation.org/about/history/
3 http://www.barnesfoundation.org/about/campuses/Philadelphia
4 It was also effective at treating gonorrhea.