Neanderthals, Denisovans, and Homo sapiens cohabited in Europe 45,000 years ago. So, why are we the only remaining ones?

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This webpage was produced as an assignment for an undergraduate course at Davidson College. About the author: Nicolas Pinzon

A genomic and anthropological collaborative study of a cave in Germany shows that Homo sapiens habited northern European lands 45,000 years ago; far before the extinction of Neanderthals. This proves that contrary to previous beliefs, Homo sapiens, Neanderthals, and Denisovans cohabited European land until the extinction of the latter two.

How did Homo Sapiens come to be the only living hominid species in the modern world? Do we have a single ancestor or did we fight off competing species? Answering these questions is not as straightforward as you may think. In fact, our understanding of human evolutionary history has been assembled in a fascinating manner. Bone fragment by bone fragment, cave by cave, and tool by tool, we continue to learn seemingly insignificant facts that all together come to form our understanding of human evolutionary history. In the eyes of some skeptics: calculated guessing at each step.

But why is there no Neanderthals or Denisovans alive now? Opinions range widely. Lots of scientists argue that competition against Homo Sapiens caused their demise, while others claim climate change, or a still unknown cause can explain their inexistence better. Current theories hypothesize a model under which Denisovans and Neanderthals co-existed with Homo Sapiens in Northern African lands early on, but expanded throughout Europe and Asia, and met their ends thousands of years later. The model argues that it wasn’t until after the Neanderthal and Denisovan extinction that Homo Sapiens migrated to Europe, Asia, and the rest of the world. Writing in Nature, Mylopotamitaki et al.⁵ show that Homo Sapiens habited Northern European lands as early as 45,000 years ago, strongly refuting the theory that Neanderthals disappeared from this area long before Homo sapiens arrived. But how did they prove this? Same as we always have: bone fragment by bone fragment, cave by cave, and tool by tool. 

The Lincombian-Ranisian-Jerzmanowician is a well-identified northern European technocomplex of around 45,000 years ago. Fieldwork that first identified it, happened at multiple sites between 1926 and 1938 and placed Neanderthals as the forgers of found technology and inhabitants of the territories⁶. In 2016, researchers of the Mylopotamitaki et al. research group returned to Ranis, one of the major cave sites of the Lincombian-Ranisian-Jerzmanowician in Germany, to clarify previous findings. 

The first step they took was to reopen the main excavation trench. They classified the ground they encountered into corresponding layers to that of the 1926-1938 excavation and looked for tools and remains that would confirm previously formulated information. For the most part, they did. Ground composition throughout all layers matched previous reports and even two artifacts were found that matched previous hypotheses: fragmented blades with double-sided sharp edges, very characteristic of this specific time and technocomplex. But layers 8, 9, and 10 held one more secret. In total, 13 hominid bone specimens were found, whose DNA would counter every formulated hypothesis to date. 

First, researchers analyzed the proteome of these specimens, or in other words the set of amino acids conforming proteins in the sample. For all samples, the amino acid positions recovered matched with the Homininae reference proteome, thus confirming the hominin origin of the samples. But this was not enough to confirm the type of hominin the remains belonged to. To decipher this, researchers turned to analyzing the samples’ mitochondrial DNA. Of the specimens, 11 of the bone samples resulted in enough sequencing reads to comparatively assess DNA origin using informative positions, known to be different in the genomes of Neanderthals, Denisovans, and Homo Sapiens. These informative positions matched every skeletal fragment sequenced to Homo Sapiens, with an average match rate of ~98%. But what are Homo Sapiens remains genetically dating back to between 40,918 to 49,105 years ago doing in sediments carbon-dating back to a range of 42,200 to 46,950 years ago in northern Europe? Further, why do ALL samples match to the Homo Sapiens genome? 

As amazingly as it may seem, the evidence shows that the Ranis site of the Lincombian-Ranisian-Jerzmanowician was made and inhabited by Homo Sapiens around 45,000 years ago. The researchers suggest “this evidence would create a complex mosaic picture of Neanderthal and Homo sapiens groups in Europe between about 55,000 to 45,000 years ago.” But what does this exactly mean? Did Homo sapiens cohabitate in northern Europe with Neanderthals until the extinction of this latter group came to be? Were Denisovans a part of this group too? Did Homo sapiens outcompete both of these groups and assert themselves over today’s world? 

With the evidence presented by Mylopotamitaki et al., a more fitting model would be one under which all modern hominids (Neanderthals, Denisovans, and Homo sapiens) migrated out of Africa early on. These species would dynamically coexist in European land until the extinction of Neanderthals and Denisovans, leaving Homo Sapiens alone in the world. However, the larger question in the field remains unanswered. How exactly did these two species become extinct? From a technological point of view, there is no evidence that these species lagged in tool and shelter making, or that there were other mechanisms through which Homo sapiens could outcompete Neanderthals. Contrarily, an argument could be made that Neanderthals should have outcompeted Homo sapiens in European lands, having hundreds of thousands of years to evolve beneficial traits in colder climates. A more sensible argument could be that Homo sapiens drove the Neanderthal and Denisovan extinction through extensive mating. It is well described that we inherit part of our DNA from both of these groups, indicating a long history of mating between species. It is possible that preferential mating for all species with Homo sapiens could have resulted in a mixed species containing very high amounts of Homo sapiens ancestry. This could also not be the case though.

Nevertheless, further research is warranted. Studies like these are severely limited by the amount of degradation ancient DNA suffers, and the fact that the only information we have is that which we find: not a lot. Further, genomic information is often not enough to answer complex questions like the cause of Neanderthal and Denisovan extinction. It may take one lucky expedition, or thousands of more years to fully assemble our evolutionary history, but bone by bone, tool by tool, and cave by cave, the answer to our will be deciphered. 

References

1. Brunet, M. et al. New material of the earliest hominid from the Upper Miocene of Chad. Nature 434, 752–755 (2005).

2. Rogers, A. R., Bohlender, R. J. & Huff, C. D. Early history of Neanderthals and Denisovans. Proc. Natl. Acad. Sci. 114, 9859–9863 (2017).

3. Reich, D. et al. Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature 468, 1053–1060 (2010).

4. Stringer, C. The origin and evolution of Homo sapiens. Philos. Trans. R. Soc. B Biol. Sci. 371, 20150237 (2016).

5. Mylopotamitaki, D. et al. Homo sapiens reached the higher latitudes of Europe by 45,000 years ago. Nature 626, 341–346 (2024).6. Stuttgart, Gustav Fischer. Die Ilsenhöhle Unter Burg Ranis/Thüringen. Eine Paläolithische Jägerstation. (1977).

6. Stuttgart, Gustav Fischer. Die Ilsenhöhle Unter Burg Ranis/Thüringen. Eine Paläolithische Jägerstation. (1977).

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