Neanderthals

Neanderthals, an extinct group of ancient humans, once roamed across Western Eurasia. These robust and resilient individuals appeared during the mid-Middle Pleistocene and coexisted with early modern humans in Europe around 45,000 years ago, eventually vanishing around 40,000 years ago.

Neanderthals were incredibly adaptable and thrived in the harsh, ever-changing climates of their time, dealing with advancing and retreating ice sheets. Their short, powerful build and large brains helped them survive and hunt some of the biggest creatures of the Ice Age, like mammoths and woolly rhinoceroses. Interestingly, we modern humans share a common ancestor with Neanderthals, dating back to Africa around 550,000 to 750,000 years ago. When both species coexisted in Europe, they not only competed for resources but also interbred. This means that a bit of Neanderthal DNA still lives on in us today.

There was another human species closely related to the Neanderthals—the Denisovans. These two groups are like sister species, splitting from a common ancestor more recently than either did from modern humans. The Denisovans are mostly known from the Denisova Cave in Siberia, where researchers found a remarkable bone fragment from a young girl who had a Neanderthal mother and a Denisovan father. This discovery was a significant find in understanding the interbreeding between these groups.

The first Neanderthal fossils were unearthed in the early 19th century, but at first, people didn't realize they were looking at an archaic form of human. The unique features of these skeletons, found in places like Engis in 1830 and Forbes Quarry in 1848, were initially attributed to diseases. It wasn't until 1856, when a more complete skeleton was discovered in the Neander Valley in Germany, that scientists began to recognize these bones as belonging to a distinct species, later named Homo neanderthalensis. Pinning down exactly when Neanderthals first appeared is tricky due to the gradual nature of evolution. However, we know that Neanderthal-like features began to emerge around 600,000 to 400,000 years ago, becoming more pronounced over time. The classic Neanderthals, with all their recognizable traits, are believed to have developed around 70,000 years ago.

Neanderthals were incredibly widespread, with their remains found from Spain and the Mediterranean all the way up to Northern Europe and Russia, and as far east as Uzbekistan and Siberia. This shows just how adaptable they were to different environments. Neanderthals had a unique and distinct appearance, shaped by the Ice Age conditions they lived in for so long. They were short and stocky, with Neanderthal men averaging about 169 cm tall and women around 160 cm. Their broad, deep ribcages and robust frames made them well-suited for the cold climates. They also had heavy brow ridges, large faces, and prominent noses, but they lacked chins, which set them apart from modern humans. Interestingly, they had even larger braincases than we do, although their faces were less protruding than those of many earlier archaic humans. When it comes to hair and skin color, Neanderthals likely had quite a bit of variety. DNA from some specimens suggests that some had pale skin and red hair, like those from Italy and Spain, while others, like those found in Croatia, might have had darker skin and brown or red hair. This variability shows that they were a diverse group, adapting to their environments in different ways.

Life for Neanderthals was tough and often dangerous. Almost all well-preserved adult skeletons show signs of trauma, particularly around the head and neck areas, likely due to their hunting methods. They had to get close to large prey animals, which was risky business. Yet, many of these injuries show signs of healing, indicating that Neanderthals cared for each other and helped their wounded recover. Despite this care, their life expectancy was low, reflecting the physically demanding and perilous nature of their lives. Their diet was largely meat-based, with Neanderthals hunting a wide range of herbivorous animals, including bison, wild cattle, reindeer, deer, ibex, and wild boar. They even hunted the enormous woolly mammoths and woolly rhinoceroses, which required exceptional hunting skills and coordination. But their diet wasn't all meat; they also consumed plants, such as legumes, grasses, seeds, and fruits. They cooked their food and may have known about the medicinal uses of plants.

In terms of technology, Neanderthals are often associated with Mousterian lithic technology, which involved creating tools from flint flakes. These tools included side scrapers, retouched points, and small hand-axes. While they used relatively few bone tools, they likely made use of wooden tools as well. From around 200,000 years ago, Neanderthals were able to control fire, using it to produce birch-bark pitch, and possibly much earlier. They mostly used natural shelters like caves, where they made fires for warmth, cooking, and tool-making. Traditionally, Neanderthals were thought to be less intelligent than modern humans, lacking the sophisticated culture and symbolic thinking that might have given our ancestors an edge. However, this view has changed. Neanderthals were clearly a complex group. They hunted in coordinated groups, cared for their injured, and used fire and tools skillfully. They even buried their dead intentionally and constructed stalagmite rings in the Bruniquel cave in France, dating back 176,500 years, indicating planning and possibly symbolic behavior. They also decorated marine shells and used red ochre, a practice seen as early as 200,000-250,000 years ago, paralleling similar practices in Africa. These were not simple brutes; their disappearance cannot be attributed solely to a lack of intelligence compared to modern humans.

Around 55,000 years ago, the main wave of modern humans migrating out of Africa encountered the Neanderthals in the Near and Middle East. This wasn't the first time the two species met; there is evidence suggesting that some genetic exchange occurred roughly 100,000 years ago, possibly in the same region. However, it was the later encounter, around 55,000 years ago, that left a significant genetic mark on our species. As modern humans spread across Eurasia, they reached Europe around 45,000 years ago, bringing much larger groups and a higher population density compared to the Neanderthals. This sudden influx led to increased competition for resources, and within a short period—on a prehistoric timescale—the Neanderthals disappeared from the fossil record around 40,000 years ago. The reasons behind their disappearance are likely complex and multifaceted. Besides competition with modern humans, another critical factor could have been the climate, which was far more unstable during that period than previously recognized. This instability may have put additional stress on the Neanderthal population, which was already significantly smaller than the incoming modern human groups. Interestingly, interbreeding between Neanderthals and modern humans not only impacted the genetic makeup of our ancestors but also helped them adapt to the colder European climate. As a result of these interactions, non-African humans today carry about 2% Neanderthal DNA on average. However, this genetic mingling was not without complications. Research suggests that interbreeding could lead to decreased fertility and higher rates of miscarriages, particularly when male offspring inherited a Neanderthal Y chromosome. This factor, combined with the significant difference in population sizes, suggests that interbreeding may have contributed to the Neanderthals' decline, potentially absorbing them into the larger modern human population. Ultimately, the disappearance of the Neanderthals likely resulted from a combination of factors, including intense competition for resources, challenging environmental conditions, and genetic mixing with modern humans. While the full story is still being uncovered, we continue to learn about the genetic influence Neanderthals have had on us. So, there's definitely more to explore in this captivating chapter of human history.