Many millennia ago, in the ancient forests of Ireland, early humans thrived in spite of competition from other predators like bears and wolves. In the present day, the area, known as the Burren, is a rocky landscape with virtually no trees in sight.

The Burren: Heart of Stone is a two-part documentary series that first premiered on the Irish TV network RTE in April 2021. Award-winning Irish actor Brendan Gleeson served as the narrator. It focuses on the titular area in present-day County Clare, which has a jagged landscape filled with caves and ancient stone structures.

Before the premiere of the documentary, it was widely believed that the earliest denizens first settled in the Burren around 12,500 years ago. Many people believed so due to the many landmarks dotting the landscape of County Clare and the entire country. 

Were farmers the first to settle in Ireland, around the time of the Neolithic Revolution–erecting walls and stone structures around the Burren? Alternatively, could they be the successors of a much earlier group of humans who arrived there? If so, how are they different from our initial perceptions of early humans? 

The Burren is a rugged landscape located in County Clare in Western Ireland. The area spans around 530 square kilometers (200 square miles). The villages of Lisdoonvarna, Gort, Corofin, and Kinvara encircle this particular area.

Before the Burren became the rough landscape it is today, the place was completely different from when the early humans first arrived. Then, it was a primeval forest filled to the brim with ancient trees and thick undergrowth, making it the ideal habitat for many different plant and animal species. 

Sometime after, this community of hunters and gatherers paved the way for an agricultural society, and many buildings were constructed throughout the Burren. While their farming methods eventually transformed the forest into the present landscape, their stone structures remain standing. 

It is currently estimated that there are around 70 structures from the Neolithic that dot the Burren, with more than half of them found in County Clare. There are four types of these megalithic structures: portal tombs and dolmens, wedge tombs, court cairns, and passage tombs.

In 1854, while working on the West Clare Railway, workers in Newmarket-on-Fergus uncovered vast caches of gold dating back to the Bronze Age inside the tombs and mounds constructed by the early people. 

Due to the rich history behind the Burren, archaeologists and amateur historians from all over have been flocking to the region over the years, wanting to learn more about it. However, some visitors also visit the place to try and seek out any hidden treasure. Regardless, the Burren is highly valued by both the locals and the outsiders.

Despite being studied extensively by experts and amateurs, much of the Burren remains a mystery. According to the website Independent.ie, Costello said, “The Burren landscape is a place shrouded in mystery, but in every rock and every stony field, there is a story waiting to be told.”

“It is one of the most diverse landscapes on earth, teeming with rarities from nature, a criss-cross of stone walls, and an abundance of ancient monuments,” Costello further added. Reports say that part 1 of the documentary, titled “Symphony of Life,” focuses on ecological and geological features that can only be found at the Burren. 

Costello spoke with various experts in the second half of the documentary, titled “Song of our Ancestors.” The discussion was about the pioneering denizens of the once-lush Burren and what their lives were once they settled down within the region. 

Immediately after the premiere, experts began to see that there were still a lot of things to be discovered about the early inhabitants of Ireland.

Some people wondered what these early humans were like during that time. According to the reports, shifting cultivation was being practiced by these prehistoric denizens when they first resided in the Burren’s coastal areas.

Before the agricultural revolution, the early people of the region sustained themselves through fishing and hunting. While they primarily resided on the coast, they would occasionally venture inland to gather nuts and berries in order to complete a balanced diet.

By around 6000 BC, the early society of the Burren changed dramatically with the arrival of newcomers originating from modern-day Turkey. These new arrivals brought with them agriculture to the country, which is now the earliest evidence of farming–located right in the Burren. 

Contrary to what was generally believed, evidence indicates that the encounters between the two groups may not always have been violent. If anything, the farmers and the hunter-gatherers might have had friendly interactions between them–at least for some time. Skirmishes were believed to have happened, but there were also times when the two groups peacefully lived side by side.

The bone fragments that were studied came from a farmer from that era. As it turns out, that individual was shown to have a strong genetic link to hunter-gatherers. In particular, the farmer may have been the great-grandchild of someone from the hunter-gatherer society.

As time went by, the nomadic lifestyle of the hunter-gatherers eventually disappeared, giving way to the increasingly-popular agrarian lifestyle that was introduced to them by the secondary settlers. Thus, agriculture became a dominating force in Ireland. 

This shift in Western Ireland’s neolithic society would also alter the landscape of the Burren permanently.

Although the hunter-gatherer people faded away just as the Burren became a rocky landscape, their legacy continues not just in the form of remains but in their genes as well. After all, they did manage to interbreed with the agricultural newcomers for quite some time.

With how they managed to uncover the ancestry of that individual, it follows that many have wondered what methods scientists like Dr. Cassidy used to achieve those things. Perhaps other things about the early people can be unraveled using those same techniques.

Using genetic sequencing on the remains of the early inhabitants, Dr. Cassidy and others uncovered surprising truths about them. For example, unlike the present-day natives of Ireland and the neolithic farmers who arrived, the hunter-gatherer people possessed dark skin and blue eyes.

As it turns out, the methods used by Dr. Cassidy to decipher the genetic code of early people are quite similar to those being used by forensic scientists to solve crimes today. Since both involve the use of DNA samples, it makes sense to make some sort of comparison.

This discovery was unexpected since no one would imagine that the early inhabitants of Ireland and the rest of the British Isles would have dark skin before the introduction of agriculture. It is a stark contrast to the paler-skinned population of present Ireland.

Cheddar Man is an individual whose fossilized remains were first discovered in 1903 in Southwestern England. Like the early inhabitants of the Burren, he was also a member of a hunter-gatherer community and is believed to have lived around 10,000 years ago.

DNA from the Cheddar Man was extracted from parts of his skull in 2018 by a group of researchers from the Natural History Museum in London. By using the process of genetic mapping, it was revealed that the individual similarly had darker skin like the Burren hunter-gatherers, though his eyes were green, he had wavy or curly hair, and he was from the Mesolithic.

This discovery in Great Britain was met with a similar level of shock to the one in the Burren. This is due to the fact that nearly all of recorded history in the British Isles was about the descendants of the light-skinned, dark-eyed secondary settlers who aren’t far off from the present-day inhabitants of Southwestern England in terms of appearance.

Another reconstruction was made public in 2022, with much consideration from the latest DNA research. As it turns out, some of the Cheddar Man’s genes are still present today, which was proved by a discovery made in 1997.

Some people have wondered what caused experts to believe that the early stone age inhabitants were light-skinned in appearance. They wondered why these recent discoveries made big waves in the scientific community. 

In warmer climates such as those in Africa, having a darker skin tone means greater protection from the sun’s ultraviolet rays, lessening the likelihood of getting skin cancer. On the other hand, having a lighter complexion becomes advantageous as you move north. This is because lighter skin means being able to maximize vitamin D production from sunlight exposure, which is much less in the northern regions.

According to the team that was investigating the Cheddar Man, the shift in skin tone may have occurred later than expected–presumably around the time that the neolithic agricultural society expanded westward.

While the discovery was generally met with shock, some were skeptical. However, scientists like postdoctoral researcher Tom Booth are able to explain the reasoning behind it.

Dr. Booth also stated that pale eyes were already in Europe long before the pale-skinned, wavy-haired Neolithic farmers arrived. “[Cheddar Man] reminds us that you can’t make assumptions about what people looked like in the past based on what people look like in the present,” he further added.

According to the website Ireland Calling, Dr. Bradley said, “The earliest Irish would have been the same as Cheddar man and would have had darker skin than we have today.” He added that central countries like Luxembourg, Hungary, and Spain served as the points of origin of the Irish hunter-gatherer communities.

Even though the shift in complexion happened later than expected, environmental factors were still the main cause behind it, according to experts.

All the discoveries made in the Burren, alongside the Cheddar Man of Great Britain, culminate into painting a relatively clear picture of human evolution. While the hunter-gatherer people of the Early Stone Age Burren are long gone, traces of them still remain in the present day.

The Burren: Heart of Stone took 13 years to complete, and it involved a lot of painstaking research. Needless to say, people like director Katrina Costello and Dr. Cassidy are reveling in the fruits of their labor as their work becomes recognized all around the world.