Science | 1.8 Million year old skull challenges human evolution

Science | 1.8 Million year old skull challenges human evolution

The unearthing of a Hominin skull is causing controversy by implying that diversity established as belonging to different species of early humans may, in fact, all be attributed to variations in the same species. 

Exquisitely preserved, the uncovered skull exhibits novel features, akin to no other from previous findings. 

The 1.8 million year old skull was found in Georgia, at a site in Dmanisi, by anthropologists from the University of Zurich. Exquisitely preserved, the uncovered skull exhibits novel features, akin to no other from previous findings; this skull comes as the fifth addition to the Dmanisi group of skulls. In appearance, when compared to the rest of the Dmanisi collection, the latest skull shows the longest face, with a large jaw and teeth, that contrasts to its tiny brain, established as the smallest in the group.

Now, experts are citing this discovery as one of the most important fossil findings to date. The completeness of the skull is unquestionable, heartening anthropologists and adding support to the conception of new theories based on this finding. Professor Christoph Zollikofer of Zurich University’s Anthropological Institute states the importance of the unique finding bluntly:  “This is the first complete skull of an adult early Homo. They simply did not exist before.” Prior to this skull, the Homo genus of Great Apes, which emerged roughly 2.4 million years ago, and includes humans in its lineage, did not have an intact skull preservation.

The completeness of the skull is unquestionable, adding support to the conception of new theories

Furthermore, the foundation of evolutionary theory, as we know today, is based upon previously found human fossil remains, which are known to be incomplete. The current central idea classifies the fossils as different species, due to differences in jaw bones and brain cavities. However, in light of the unique dimensions of the new finding, the team decided to compare skull variation from the Dmanisi remains to those of normal skulls, in both humans and chimps. They discovered the variation met standard expectations, as would also be seen in humans and chimps. Consequently,  the team now suggests that the exhibited diversity may merely account to a single group of Homo erectus.

Nevertheless, Homo erectus represents a vast far reaching early human species: despite originating in Africa, they managed to migrate across the world. Thus, some find it implausible to assume that early African fossils can now be “reasonably be lumped into an evolving Homo erectus lineage,” as Chris Stringer, head of human origins at the Natural History Museum in London, puts it. 

Looking ahead, this skull offers the opportunity for more open questions into the evolution of humanity. With further work being dug out in the Dmanisi, it is only time before new discoveries build on to the debate. Our complex ancestral history requires many more intact fossilized remains before conclusions can be made.

 

Sofia Popov

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