Humans are a species with strong African roots. Our species evolved there. So did our ancestors, stretching back to before we split from chimps around 7 million years ago. But there's one fossil that challenges this perspective. It's called Graecopithecus freybergi and - as the name suggests - it comes from Greece (Graec = Greek, pithecus = ape). Despite this distinctly un-African heritage, new research suggests it may be a human ancestor.
Who is Graecopithecus?
The defining specimen of Graecopithecus freybergi conists of a bit of mandible. Despite these rather lacklustre remains, it's already earned a nickname: El Graeco. No word yet on if it's connected to the infamous criminal with a similar title.
El Graeco is not actually a new fossil. It was actually discovered back in 1944, allegedly by occupying Germans digging a bunker in Athens. Unfortunately, that bunker did a bit of damage to the site of the fossil making it impossible for further research to be done. I guess screwing with fossils is another crime the Nazis were guilty of. However, it was coated in sediment that was dated to the Miocene, around 7 million years ago. Since then a tooth was found in Bulgaria which has also been assigned to the species.
Since then it's been the target of some controversy, with some researchers denying it even exists. It's been claimed it's actually just an example of Ouranopithecus macedoniensis. However, the two species are separated by a couple of million years; with Ouranopithecus clocking in at closer to 9 million years ago. As such, it seems fairly clear the two species are distinct. Additionally, there's also been disagreement with whether the tooth actually belongs to the species, with some claiming it is too small to fit.
Apart from that controversy, there's not much else to note about the species 70+ year history. With so few remains attributed there's not much more to add.
Can it be linked to us?
And that was the end of the story. El Graeco was cleaned up by the Natural History Museum in London and we could all go home without re-writing any textbooks on human evolution. But everything changed when the computer scanners attacked. Detailed models of the mandible revealed they had a unique tooth root. This confirmed that the Bulgarian tooth was a match.
Oh, and the tooth root was also a match for the human family. *record scratch*
See, early apes have two or three clearly diverging roots in their teeth. By modern apes this had become just two roots is two roots. Whilst El Graeco does have two roots, they're fused halfway up. Only 2% of ape teeth have this fusion. However, this is seen in ~20% of early members of the human family. Meanwhile, ~20% of modern humans have the similar but more derived from of this unique root; called a "Tomes root".
In other words, if you don't have a fused tooth root you aren't necassarily a member of the human family. But if you do have one, odds are that you do belong to us. And since El Graeco had one, well. . . I'll let you figure that one out.
But is it possible?
However, before we go running off and re-writing all the textbooks there are a few caveats to bear in mind. Notably, we're dealing with just one fossil (and one tooth). Given there's a 2% chance for this to happen in an ape, a sample size of 1 is a bit small for us to draw massive conclusions from it. Additionally, that root seems more humans than that of the other known human "ancestors" from around this time. The chronology doesn't quote add up.
(ancestors being in quotemarks because we don't actually know they're ancestors. Just likely closely related to ancestors).
Notably, there are issues that the authors are aware of. T he Torygraph offers a fairly certain perspective that "these are totes human", but the actual researchers are more cautious. They note that:
Accordingly, the most parsimonious interpretation of the phylogenetic position of Graecopithecus is that it is a hominin, although we acknowledge that the known sample of fossil hominin root configurations is too small for definitive conclusions.
Although I thin this does raise an interesting question: is it even possible that the human family initially evolved in Europe?
Well, it's not as unlikely as it might seem. Despite our strong African heritage, there were also many apes in Europe during the early part of our evolution. The climate was fairly different back then, producing an environment favourable for apes. In fact, more than half a dozen ape species are known from across Europe at this time.
Increasing aridification at the time of El Graeco was spreading across Europe and North Africa. Thus, a species well adapted to that environment - as Graecopithecus surely was - could have many habitats to choose from. Perhaps even being able to expand back into Africa, where the rest of human evolution occurred.
Conclusion
However, I do have to point out that this is a lot to infer from a single tooth. More fossils are needed. But since only one other has been found in the 70+ years since El Graeco was found, I'm skeptical that we'd find more. It looks like the origins of our lineage are going to remain a mystery for a while longer.
References
Böhme, M., Spassov, N., Ebner, M., Geraads, D., Hristova, L., Kirscher, U., Kötter, S., Linnemann, U., Prieto, J., Roussiakis, S. and Theodorou, G., 2017. Messinian age and savannah environment of the possible hominin Graecopithecus from Europe. PloS one, 12(5), p.e0177347.
Fuss, J., Spassov, N., Begun, D.R. and Böhme, M., 2017. Potential hominin affinities of Graecopithecus from the Late Miocene of Europe. PloS one, 12(5), p.e0177127.
Smith, T.M., Martin, L.B., Reid, D.J., de Bonis, L. and Koufos, G.D., 2004. An examination of dental development in Graecopithecus freybergi (= Ouranopithecus macedoniensis). Journal of Human Evolution, 46(5), pp.551-577.
Spassov, N., Geraads, D., Hristova, L., Markov, G.N., Merceron, G., Tzankov, T., Stoyanov, K., Böhme, M. and Dimitrova, A., 2012. A hominid tooth from Bulgaria: the last pre-human hominid of continental Europe. Journal of Human Evolution, 62(1), pp.138-145.
Gu, Y., Zhang, Y. and Liao, Z., 2013. Root and canal morphology of mandibular first premolars with radicular grooves. Archives of oral biology, 58(11), pp.1609-1617.
