A part of the Nova series of documentaries, Dawn of Humanity tells us an engaging story of two of the most important discoveries in recent history. Northwest of Johannesburg, in a complex of limestone caves famously known as the Cradle of Humankind, paleoanthropologists have recently found fossilized remains that could potentially reshape our understanding of human evolution and help us fill the gaps in the fossil records that support it (Dawn of Humanity).
The central character of the documentary is American paleoanthropologist Lee Rogers Berger, who we know from his Radiolab interview concerning the Taung Child, a fossil that forever changed our outlook on the origin of modern humans. For the first half of the documentary, Lee talks about his discovery of Australopithecus sediba in the caves that were blown by miners searching for limestone (Dawn of Humanity). We learn that all australopiths share characteristics of both apes and humans, but that sediba has unique features that were never seen before. These include a very long arm that can be found in chimps with a hand similar to the one possessed by humans. In fact, with its opposable thumb and forefingers, the creature could have even been a tool user. The fact that these remains are so well preserved means that the bones could help scientists decipher the lives of these ancient creatures – finding out about their dietary habits and causes of death can then in turn tell us new things about our own evolutionary patterns (Dawn of Humanity).
The second part of the documentary revolves around an even bigger discovery, both in its importance and scale. In the depths of one of the caves located at the Cradle of Humankind two explorers working with Berger found a chamber that was literally full of fossils. Upon seeing the photos of this discovery, Berger wrote a Facebook post calling for archaeologists that are skinny and brave enough to crawl through the tight passages of the Rising Star cave. He got an overwhelming response from scientists all over the world, all willing to work with him on unearthing this amazing thing that he found. The first fossil they retrieved was a jawbone. Upon examining it, Berger concluded that it was too small to have belonged to an australopith. He compared the teeth to the ones found in Homo habilis – one of the first representatives of our genus, and saw that the teeth of Homo habilis were more curved. It was neither an australopith not Homo habilis. In the days that followed, Berger's team excavated almost 2000 bone fragments that belonged to more than twelve individuals. The sheer amount of fossils is unprecedented, but what is even more unusual is that almost all of them belonged to a human ancestor. This could imply that Berger stumbled upon some primitive kind of a burial ground. The practice of burying our dead is fairly new in the history of our species, so these kinds of implications should be treated with great care. What ultimately revealed the nature of these fossils was a carefully retrieved skull fragment. Homo naledi, named after the cave where they were found, are a strange mix of chimps and humans and another stop on the complex path to the evolution of modern humans (Dawn of Humanity).
Although these discoveries may raise more questions than answers, the one thing we may take from them is that evolution is not a linear, easily understood mechanism, but rather an intricate and „bushy“ process that we may never completely decipher.
Works Cited
Dawn of Humanity. Dir. Graham Townsley. Perf. Lee Rogers Berger. N.d. PBS. PBS. Web. 17 Apr. 2016.
