By Mark Carnall, on 20 September 2012
Volunteers are very much the spine and vital organs of museums and we are eternally grateful for all the work and support they give to museums. Anthropologist Rebecca Davenport has been working on the Grant Museum collection of fossil human casts and models. Over to Rebecca…
Most of us have no problem distinguishing between ourselves and other animals. Whilst the Grant Museum’s main attractions inspire reactions ranging from disgust to awe, I’d wager that gazing upon a jar of moles or the bones of an extinct quagga fails to arouse feelings of commonality or a sense of shared identity. After all, these specimens look completely alien and lack any element of we might consider “humanness”.
Yet a newly accessioned collection calls into question this clearcut distinction. John Napier, twentieth century primatologist, palaeoanthropologist and physician (also notorious for his serious but inconclusive investigations into the Bigfoot phenomenon) amassed a collection of hominin fossil casts from various periods of human evolution, some of which have come to rest at the Grant Museum. This material raises some important issues. Firstly, should we regard it as somehow separate from the museum’s non-human animal collections and, if so, at what point during our evolutionary history should we infer this separation? Essentially, when did we become human?
It is not too difficult to see a distinction, morphologically and behaviourally, between our closest living relatives, the common chimpanzee (Pan troglodytes) and bonobo (Pan paniscus), and ourselves (Homo sapiens). However, this becomes increasingly blurred over evolutionary time as we move closer to the present. Australopithecines (c. 4 – c. 2 Ma) had ape-sized brains but, like us, probably walked habitually on two legs. A somewhat larger brain size has been calculated for Homo habilis (c. 2.5 – 1.44 Ma), a species that probably used tools but were still behaviourally and anatomically very different to us. Homo erectus (c. 1.9 Ma – Homo heidelbergensis (c. 700 – c. 200 ka) and Homo neanderthalensis (c. 200 – c. 28 ka) appear to have buried their dead and engaged in ritualistic activities – the beginnings of religion? – and we are fairly sure that they communicated using complex language.
What this collection highlights is that, despite our inherent tendency to regard ourselves as a species that is decidedly distinct from other animals, we are unable to agree on a well-defined threshold that our ancestors crossed to become human. This dichotomisation is, in fact, part of a more general propensity to categorise and classify what we see around us in nature. Take, for example, the concept of species. We call lions “lions” and tigers “tigers”, yet this becomes largely meaningless when they interbreed to produce fertile female ligers. Similarly, there is evidence for possible interbreeding between neanderthals and Homo sapiens with studies suggesting the presence of neanderthal DNA in some modern human genomes. So were neanderthals humans? Of course, scientific classification is integral to the study of biological organisms, living and extinct, but we should remember that we, ourselves, generate and enforce these categories; they do not exist inherently in nature.
When next taking a gander at the Grant museum’s weird and wonderful specimens I, for one, will spend more time considering what I have in common with the freshwater sponge, the hippopotamus and the tapeworm. It becomes difficult to conceive of a definitive boundary between human and non-human animals when we consider that our differences accumulated along a gradual continuum during millions and millions of years of evolution. So John Napier’s hominin collection has proved humbling to say the very least. Homo sapiens may have evolved brains large and complex enough to categorise, classify and attempt to understand the natural world, but we are still very much a part of it.