Should Homo habilis Be Reassigned To The Genus Australopithecus?
To answer this question, it is necessary to assess how well Homo habilis fits into the genera Homo and Australopithecus, and where it fits best. Homo habilis is the least similar species in the Homo genus to the modern human. Like Australopithecus, it has a short body with very long, ape-like arms, which makes it very different to the modern human. However, Homo habilis is different from the Australopithecines in that it has a much larger cranial capacity (around 630cc), although this is still smaller than that of the modern human (around 1400cc). They also had much smaller, human-like, teeth. Already, we can see that it is difficult to classify habilis, as it doesn’t appear to truly fit into any one genus. It appears to be more of an intermediate species, one that links the two genera together, and the evolution of Australopithecus to Homo erectus, one of the next earliest human ancestors.
While Homo habilis appears to retain many of the primitive features we see in the Australopithecines, such as their ape-like body structure, their smaller brains and their small stature (in general, they didn’t stand more than just over 4ft tall), there are other features which are not necessarily physical, that link them to the Homo genus. For instance, remains of Homo habilis are often found alongside stone tools, such as those remains found in Kenya. This makes us believe that these hominids were in fact closer to ourselves than we at first believed – they had intelligence, and made a conscious effort to make tasks such as hunting for food easier. As there is no hard evidence for the Australopithecines using tools at the present, this is one factor which can lead to the classification of habilis as Homo.
Another way in which it would be very useful to classify hominids such as this would be to use genetic techniques. From this, we would be able to determine truly how close to other species of either genus this species is. However, at present, no DNA has been found, or hasn’t been analysed, for this species – it is possibly too old, as it has already been fossilised. The earliest found DNA so far is for Homo neanderthalensis. If we cannot get DNA for the species now, it is probable that we never will. Another problem with using genetics is that two organisms may look very different but have very similar genomes – should we consider reclassifying these too, if we are considering this? For instance, we could argue that Pan troglodytes should actually be Homo troglodytes if we use this rule.
Although we cannot analyse genetics to find out how closely related species are, recently (2007), findings have suggested that Homo habilis is in fact a mixture of two species that existed at the same time and had similar features, but which evolved differently to give rise to different new Homo species. This is another reason why many scientists are keen to reclassify the species as “Australopithecus habilis” – perhaps Homo erectus is not in fact descended from Homo habilis, and so should we classify them together in the same genus if they are not related?
Homo habilis seems to be a difficult species to classify: it doesn’t totally fit in anywhere. However, from the evidence listed above, Homo habilis should perhaps not be reassigned to Australopithecus. While they share similar features in appearance, there is clear evidence for evolution away from the genus Australopithecus towards the genus Homo, for instance with bigger brain sizes and increased social interaction, both of which are prominent features of the Homo genus. The species may not totally match the others in the Homo genus, but we are not trying to classify the species as one, just similar species into a genus, and this species would fit as a very early example in the evolution of the modern human.