Neanderthals: Freaks of Nature and Our Fascinating Sister Species

Of all the human species that have ever roamed the Earth, Neanderthals remain among the most fascinating. Their likeness and close relationship to modern humans have led many to refer to them as our “sister species.” Remarkably, traces of their DNA can still be found in most of us today. Despite their extinction tens of thousands of years ago, scientific research continues to shed light on their extraordinary biology, culture, and adaptations—many of which make them seem almost superhuman by today’s standards.

The Basics: Height, Weight, and Build

Neanderthals lived across parts of Eurasia roughly between 400,000 and 40,000 years ago, enduring a time when life was anything but easy. While they were shorter than modern humans by an average of 14 centimeters (5.5 inches), their compact and muscular frames more than compensated for their reduced height. The tallest known specimen, Amud 1, stood at about 1.78 meters (5’10”), comparable to many modern humans.

However, what truly set Neanderthals apart was their weight. Males averaged 83 kilograms (183 pounds), while females typically weighed around 66 kilograms (146 pounds). This made them about 20% heavier than the average Homo sapiens, a fact attributed to their incredibly robust skeletons and dense muscle mass. Their bones were often twice as thick as ours, with especially bulky shoulders, femurs, chests, arms, and knees. These features made them extraordinarily strong and well-suited for the physically demanding lives they led.

Super Strength and Durability

Neanderthals’ incredible strength was likely an adaptation to their close-quarter hunting tactics. They used enormous spears to hunt megafauna like woolly mammoths, rhinoceroses, and wild horses. These prey animals were massive and dangerous, requiring Neanderthals to possess exceptional physical power and agility.

Studies suggest that their muscular arms were akin to those of bodybuilders, developed through the lifelong use of heavy weapons and tools. This build wasn’t merely aesthetic; it granted them the strength to carry up to 27 kilograms (60 pounds) of meat over long distances—the equivalent of walking 30 miles while carrying a toddler.

Their robust builds also endowed them with remarkable durability. Analyses of skeletal remains reveal that between 79% and 94% of Neanderthals experienced significant trauma during their lives—injuries that they often survived. One striking example involved an elderly male who had lost an arm, sustained facial injuries that left him blind in one eye, and suffered repeated ear trauma that rendered him deaf. Despite these hardships, he lived long enough for his wounds to heal, showcasing not only their physical resilience but also the social care they provided one another.

Unique Physiology: Breathing, Metabolism, and Caloric Needs

One of the most distinctive features of Neanderthals was their barreled chests, which housed a rib cage that allowed for lungs significantly larger than those of modern humans. These adaptations gave them an impressive lung capacity, up to 40% greater than the average Homo sapiens male. For example, the lungs of a Neanderthal specimen known as Kabara 2 could likely hold 9 liters of air—a capacity that rivals or surpasses elite athletes today.

Neanderthals also had wide, long noses designed for high airflow. Their nasal cavities likely helped to warm and humidify the cold, dry air of Ice Age climates, ensuring their survival in harsh environments. Coupled with a faster metabolism, these adaptations supported their bulky physiques and high energy demands. Researchers estimate that Neanderthals needed between 4,500 and 6,700 calories daily—nearly double the requirements of modern humans. This caloric intake underscores their intense physical activity and the challenging conditions they faced.

Incredible Hunting Skills and Battle Scars

The Neanderthal way of life revolved around hunting large game. Evidence suggests that their hunting methods were aggressive and direct, often involving close encounters with dangerous animals. It’s no surprise, then, that many Neanderthal skeletons show signs of injuries from animal attacks.

One study found that nearly 74% of Neanderthals had survived violent encounters with animals. These injuries weren’t merely defensive; in many cases, they resulted from Neanderthals attacking animals like bears, wolves, and big cats. The fact that Neanderthals frequently survived such encounters—despite lacking advanced medical care—is a testament to their resilience and community support.

Hands Built for Power

Neanderthal hands were another marvel of evolution. Their fingers were broader, and their thumbs extended at wider angles than ours, allowing for powerful grips. While these hands may have lacked the fine motor precision of modern humans, they excelled in strength. Neanderthals could firmly hold tools and weapons, making them formidable hunters and survivors in their rugged environment.

Superhuman Adaptations: Skin, Joints, and Hormones

Their external features were equally well-adapted to their tough lives. Genes associated with Neanderthals indicate thicker skin, nails, and hair—all of which likely helped them withstand cold climates and frequent physical trauma. Their large joints enabled a range of strenuous movements that would be difficult or impossible for modern humans. Additionally, high levels of hormones like testosterone may have contributed to their remarkable muscle mass and physical endurance.

Social Structure and Care

Despite their rough exterior, Neanderthals displayed a surprising degree of social cohesion and care for their injured. The evidence of healed fractures and long-term disabilities in individuals suggests that Neanderthals tended to their wounded, ensuring they could survive even with significant impairments. This level of social organization hints at a complex and compassionate community dynamic.

The Legacy of Neanderthals

Although Neanderthals went extinct around 40,000 years ago, their legacy lives on in modern humans. Between 1% and 2% of the DNA in people of Eurasian descent comes from Neanderthals, influencing traits ranging from immune responses to physical characteristics. Their story is a reminder of the resilience, adaptability, and ingenuity of our ancient relatives.

In many ways, Neanderthals were “freaks of nature”—but in the best sense of the term. Their extraordinary biology and survival strategies highlight the incredible diversity of the human family tree and the remarkable adaptations that allowed them to thrive in some of the harshest environments on Earth.