Denisova Caves, Russia

In a distant corner of southern Russia, close to the borders of China, Mongolia and Kazakhstan, lies a cave in the Altai Mountains that has caused a stir amongst palaeontologists. Known to the locals as Aju-Tasch, meaning Bear Rock, it has been a dwelling place for thousands of years, and the reason for all the excitement is down to the identity of some of its previous residents.

One of its more recent occupiers was an Old Believer from the 18th Century. Old Believers were a group of Eastern Orthodox Christians who objected to the reforms to their religion introduced by Patriarch Nikon of Moscow. In order to follow the old rituals, they chose to live apart from society in remote areas. The hermit who chose Aju-Tasch as his home and who clearly enjoyed the solitude, as well as the exceptional views over the Anui River Valley, was a man called Dyonisiy (Denis, in English) which is where the name is taken from – the Denisova Caves, Russia.

40 years of excavations

Exploration of the cave system by Russian scientists and archaeologists began back in the 1970s, and it became immediately apparent that this would be a challenging site. Thousands of years of occupation – including that of Denis the hermit – had left around 22 separate layers, or strata, each with its own range of artefacts.

Professor Anatoly Derevianko and Professor Michael Shunkov, along with teams from the Institute of Archaeology and Ethnography, spent forty years excavating these layers and produced some fascinating results, and they have been credited with establishing the longest archaeological timeline in Siberia.

Neanderthals, Denisovans & Homo Sapiens

The mass of accumulated evidence suggested that at least three distinct groups had occupied the caves at various times; Neanderthals, Denisovans and modern humans (Homo Sapiens). The Denisovans (tentatively named Homo Denisova) were a new species of archaic human, or hominin, based on scant evidence. They were believed to have been ‘cousins’ of the Neanderthals, perhaps a hybrid species, but the complex formation of the different sediments within the caves made this difficult to establish with any certainty.

The incredible amount of hard work and dedication invested by these teams over the decades should never be underestimated or forgotten. However, events in 2010 could be said to have eclipsed these previous discoveries.

Applied Science

The challenges of excavating a virtual palimpsest always add to the difficulty of interpreting the evidence. Countless archaeological sites around the world have yielded potentially groundbreaking results, but by their very nature are based on incomplete samples of evidence. This often means that a definitive interpretation can’t be applied in many cases. Advances in scientific methods in recent years – especially in the extraction and study of DNA -have proved invaluable in providing a wealth of supporting evidence, and this was the case with the Denisova Caves, Russia.

DNA Preserved at Denisova Caves

Extraction of DNA isn’t always an option, though, which can be frustrating to those who have worked so hard on a promising site. At Denisova Caves, however, the conditions were almost perfect; the average annual temperature of 0 C (32 F) helped to preserve the archaic DNA within the layers.

The Girls Finger

In a truly international effort, scientists from America, Europe, Australia and Russia collaborated to extract and examine a huge range of samples. They focused on mitochondrial DNA from a finger bone believed to belong to a young girl. The bone had been found along with artefacts of the Mousetarain Industry, which is the culture of tool-making associated with the Neanderthals, and had been dated to 30,000 to 48,000 years ago. However, the mtDNA showed twice as many differences to modern human DNA than that of Neanderthals. This means that the girl must have been part of a genetically distinct group of hominins, separate from the Neanderthals. And so, the Denisovans were added to the palaeo-archaeological record.

Denny The Hybrid

Further to this, research undertaken at Manchester University on hominin bone fragments discovered the genome of a ‘hybrid’ species with Denisovan and Neanderthal parents. Estimated to have been only 13 years old at the time of death, ‘Denny’, as she was affectionately named, indicates the first-ever recorded evidence of interbreeding between archaic hominin species. These findings strongly suggest that the two different hominin species met and began to interbreed about 100,000 years ago,

In another fascinating development, improved dating techniques pushed back the Denisovan occupation by 100,000 years, to around 280,000 years ago.

More mysteries to solve

These remarkable results are ascribed to the fact that teams from a range of disciplines within different countries were involved. The strategy of cross-checking data and evidence allowed for more precise dating, which meant that any interpretations could be stated with greater confidence.

From this evidence, it seems that the Denisovan people were particularly hardy, occupying the caves during several cold-climate episodes of Siberian history, as evidenced by fossil-pollen analysis. The same analysis shows that the Neanderthals only ventured into the caves once the climate had started to become relatively more warm and humid.

Whose Ancient Artefacts Were They?

But in spite of the enormous success achieved and the wealth of information provided, the Denisova Caves, Russia, still has many more secrets to reveal. As well as providing precise dates, the adjustment of the timeline raises the problem of which of these hominid species was responsible for the mass of ‘Initial Upper Palaeolithic’ artefacts. Dating from between 43 – 49,000 years in age, ornaments were discovered made from mammoth ivory and ostrich eggshell, pendants made from animal teeth, and bone points. These are the earliest artefacts to have been found in Eurasia so far, and some experts believe that ‘modern humans’ were responsible as they suggest a more complex culture. Many Russian scientists, however, claim that they are the handiwork of the Denisovan people.

The Denisova Cave Bracelet

The bracelet was found in 2008 in the Denisova Cave (pictured), in Siberia, named after Denis, a Russian hermit who lived there in the 18th century. … At an exhibition in France this year the green-hued chlorite bracelet, unearthed in a Siberian cave, was listed as 50,000 years old

Clearly, the only way to find out is to keep digging and encouraging collaboration between different countries and disciplines to provide clarification of the evidence. Who knows what rewards await the diligent and hardworking teams at Denisova, as well as at other – as yet unknown – sites in the region?