The remains of Homo floresiensis, discovered at Liang Bua on the Indonesian island of Flores in 2003, and of Homo naledi, discovered inside the Rising Star Cave in South Africa’s Cradle of Humankind, have played an important part in helping us understand the diversity and complexity of our hominin past.
H. floresiensis, dubbed ‘The Hobbit’ by the media because of its diminutive size, with a brain capacity of around 380 cm3 and standing around a metre tall, was considered by many scientists to be a deformed or microcephalic H. sapiens. However, strong physical evidence such as humeral torsion[i] and a set of teeth unique among hominins[ii] has pretty well ended the debate about its status as a species in its own right. The main disagreement now, considering the size of its brain, is whether or not it should be included in the genus Homo.
And speaking of small brains …
H. naledi was half again as tall as H. floresiensis – about the same height as a large chimpanzee – and although its cranial capacity (between 460 cm3 and 610 cm3) was considerably bigger than the Hobbit’s, it was still well short of a modern human or any of our immediate cousins such as H. neanderthalensis.
As I wrote in a previous post, however, brain size is not necessarily a reliable indicator of intelligence.[iii] H. floresiensis almost certainly made and used stone tools[iv], and recently the University of Witwatersrand’s Lee Berger announced that researchers had found evidence of fire being used by H. naledi[v]. This last was probably something of a given, since the remains of H. naledi were found in a chamber of the Rising Star Cave that could only be reached through a long, dark and twisting route that was difficult and dangerous to follow even with artificial light – without some kind of illumination it would have been virtually impossible. Still, this recent evidence adds weight to the case that this species was capable of making and using fire.
As friend and palaeoanthropologist Debbie Argue asks, however, when and how did H. naledi learn to make fire? Could they possibly have acquired the skill from a contemporary hominin, such as H. sapiens? Or was it the other way around? Or did both species learn the trick from a third hominin group?
We’ll probably never know the answer to this question, but it is fun thinking about, and – at the risk of stretching a metaphor almost to breaking point – throws another log on the fire of revaluating exactly what it means to be human.