Deep in the northern stretches of our planet, ice and permafrost hold countless relics from the distant past, perfectly preserving them like a prehistoric refrigerator. Recent years have seen the discovery of a host of different Ice Age animals, from wolf pups to baby woolly mammoths, that have laid in permafrost for over 40,000 years, only to be unearthed in a remarkably pristine condition. 

It’s a long shot, but it’s possible that we could someday find an extinct species of human preserved in permafrost like a mummy. 

Considering the closest cousins of Homo sapiens – Neanderthals and Denisovans – fell into extinction somewhere around the same timeframe of other permafrost-locked animals, there’s an intriguing possibility that we could find one of these elusive ancient humans in a similar condition. 

“It’s not a far-out idea because it is possible. It’s completely theoretical and speculative at the moment, but it is worth us considering ahead,” Dr Matthew Pope, Principal Research Fellow in Palaeolithic Archaeology at the UCL Institute of Archaeology, told IFLScience. 

“I think we should consider it a possibility. I think we should take a step back and think what is the possibility that a human from the Ice Age, whatever its species, may be found,” added Pope. 

Fossilized bones are currently the only physical remains of extinct human species that scientists have at hand, aside from odd pieces of the jewelry and tools they crafted. Their soft tissue, hair, and clothes have all perished over the millennia, but they could theoretically remain preserved if kept “on ice” at sub-zero temperatures. 

Such a discovery has the potential to be paradigm-shifting. We still know surprisingly little about the closest branches on the human family tree – especially the Denisovans, of whom we’ve only ever discovered a handful of bone fragments – so this could provide invaluable insights into how they looked and how they lived.

Just think about the discovery of Ötzi the Iceman, an ancient man found in the eastern Alps near the Italian-Austrian border. When his body was first found in the snowy mountains back in 1991, he was initially mistaken be have been a recently deceased mountaineer. However, researchers worked out that the well-preserved corpse was actually born in 3275 BCE.

“The best point of reference for this would be Ötzi. Obviously, he’s a much more recent human preserved in ice, but it showed us what cryogenic freezing can preserve in terms of clothing and organic artifacts. Even down to things like how hair is worn, tattoos, and other body modifications. All of which are very important from an archeological and scientific point of view,” added Pope.

Unfortunately, the geographical window for such a find is small. The natural range of Neanderthals is not totally clear, but there is strong evidence of their presence across Europe and a few pockets of Asia.

We know the species was adaptable, living in both the balmy Mediterranean and chilly Eurasian steppe of Siberia. In the foothills of the Polar Urals near the Arctic Circle in far northern Russia, archeologists stumbled across a site that contained a number of stone tools dating back to around 31,000 years ago. No bones were found, so it’s debatable which species lived their lives here.

While some researchers have argued that Neanderthals lived here as "a late northern refuge," that theory has been largely quashed by other archeologists who believe that modern humans are far more likely candidates. In other words, we don’t know how far north Neanderthals went or whether they were well-adapted to cold environments.

“We’re not sure how north they get and, of course, if they don’t get far north then they’re unlikely to be in the permafrost. If you look at all the animals that have been found in permafrost –  and there’s been quite a lot now –  they are mostly cold-adapted,” noted Dr John Stewart, Professor of Evolutionary Palaeoecology at Bournemouth University.

“Neanderthals have been described as cold-adapted, but that view has been questioned by people, including myself, because of the lower latitude at which they’re found,” he continued. 

While the odds of discovering a Neanderthal in the far north of Eurasia are slim, there is another intriguing avenue to look down: our lesser-known cousins, the Denisovans, lower down in Eurasia in Tibet. 

Scientists have only discovered Denisovan remains in the Denisova Cave of Siberia, as well as one specimen in the Baishiya Karst Cave on the Tibetan Plateau. Since this high-altitude location is decorated with patches of permafrost, this could be the place to look. 

“The place to look for an archaic human mummy isn’t the High North, it’s the high altitude in the Himalayas, Tibet, or something like that,” Dr Stewart explained.

“There is permafrost and there’s certainly evidence of the Denisovans in the region. It’s also a place that some people have speculated that’s where cold-adapted species have evolved,” he added. 

There’s no guarantee that we will ever discover a well-preserved extinct human relative. Permafrost-preserved animals are often found by chance in extremely remote and vast areas that are sparsely populated; if no one is looking for them, no one will find them. 

Furthermore, they must be spotted within a brief window of time when the specimen is exposed, but not yet degraded by the natural forces outside the permafrost. Since climate change is wreaking havoc with the world’s permafrost, the likelihood of a chance discovery is likely to become even slimmer in decades to come. 

Nevertheless, researchers believe that it’s still an eventuality we should prepare for because it will raise an array of ethical quandaries and practical concerns. Such a find will inevitably attract a colossal amount of media attention and public curiosity – which is something scientists and the world need to prepare for. 

“As a scientist and archeologist, I’d be incredibly excited about this discovery, but I am concerned that culturally, as a discipline, we’re ill-prepared for how we would handle such a discovery,” noted Dr Pope. 

“It should begin from the point of view that this is a human body. Not only would it be of immense scientific importance, but it would have to be cared for with a high level of ethical concern. That’s the single most important point, before anything else,” Pope continued. 

“We should caution against that temptation to make it an exhibition of something fantastical, for it to become carnivalesque,” he added.