A reconstruction shows what our closest cousin, a Neanderthal, would have looked like (Photo Credit: Flickr)

The Secret Life of Neanderthals – How our closest cousins lived, died, and still exist today

MS-LS4-2. Apply scientific ideas to construct an explanation for the anatomical similarities and differences among modern organisms and between modern and fossil organisms to infer evolutionary relationships.’

MS-LS4-4. Construct an explanation based on evidence that describes how genetic variations of traits in a population increasesome individuals’ probability of surviving and reproducing in a specific environment.

Key Vocabulary: fossil, paleontologist, extinct, adaptations, species, traits, technology, genome

Neanderthals Article Guide


When you think of Neanderthals, your mind probably conjures an image of a dull, crude brute from the Ice Ages who ultimately gave way to the smarter, superior Homo sapiens. So it may come as a surprise to learn that Neanderthals were extremely intelligent and resourceful, using advanced tools and a complex society to successfully hunt the largest animals of their day. And while Neanderthals became extinct thousands of years ago, new evidence shows that their genetic legacy lives on in modern humans. I spoke with Briana Pobiner, paleoanthropologist with the Smithsonian Human Origins Institute, on how our closest relatives lived, why they went extinct, and how they live on today

Who were Neanderthals?

Neanderthals were a species of humans who lived in Europe and Central Asia during the middle and late Pleistocene epoch, between about 400,000 and 40,000 years ago. This period was characterized by multiple Ice Ages, with global temperatures dropping low enough that much their habitat was covered in glaciers. As a result, Neanderthals were adapted to these colder climates; their bones and muscles were thicker than modern humans to help reduce heat loss. “Neanderthals lived in really cold parts of Europe and Asia, so having a shorter, squatter body is a good adaptation because it keeps in body heat,” Dr. Pobiner explains.

These were not the simple-minded cavemen seen in cartoons and movies. Neanderthals were excellent hunters, taking down woolly rhinos, mammoths, and other large game for food. Doing so meant complex hunting techniques and a sophisticated level of coordination between members of their tribes. Not only were Neanderthal brains nearly as big as modern humans, but they crafted impressive spears for hunting, had mastered containing fire, and probably made clothing to protect against the cold. “They used a type of stone tool called Levallois, which requires a lot of forward planning and skill,” says Pobiner. “They were pretty technologically advanced.”

There were some key differences between human and Neanderthal brains. While the Neanderthal  brain had roughly same volume as that of a human, their sloped foreheads afforded less room in the front of their skulls. This probably meant a smaller prefrontal cortex, the center of executive functioning in the brain. And though they made some impressive artifacts, Neanderthals left behind no needles for stitching fitted clothes and no bows and arrows.

A comparison of Neanderthal and Modern human skulls from the Cleveland Museum of Natural History shows some key differences in brain shape and facial features. (Photo Credit: Wikipedia)

However, new evidence has recently come to light that shows evidence of symbolism within Neanderthal society. Researchers recently found cave paintings in three separate sites in Spain dating to nearly 65,000 years ago, far too early to be the work of modern humans. The artists must have been Neanderthals, which would mean they were capable of abstract thinking.

Competing cousins

If Neanderthals were so smart and tough, why did they go extinct? Did humans wipe them out in an interspecies war or did they just out-compete their cousins? Or were the last straggling members of their species just absorbed into human society?

There’s no evidence of combat between the species and no fossils of humans and Neanderthals have been found together with weapons around them. We also have yet to find anything in fossil record to support that Neanderthals were taken into modern Homo sapiens tribes. “You could still tell the difference between a Neanderthal skeleton and a human skeleton, even it if was from 40,000 years ago,” says Dr. Pobiner. “It doesn’t seem that they were absorbed into the human population.” Though researchers debate the reasons why, the Neanderthal population was definitely shrinking by the time humans showed up in Europe. This would have made Neanderthals susceptible to drought, diseases, or a shortage of food due to a changing climate.

But Neanderthals weren’t the only species of humans to live during the Pleistocene. Dr. Pobiner says, “There were at least two other species besides Neanderthals that were around during the time of modern Homo sapiens.” A small population of Homo erectus was still on the scene during this time, as was Homo floresiensis, nicknamed “The Hobbit” due to its small stature and discovered in Indonesia in 2003. Our ancestors 150,000 years ago not only would have been interacting with these other species of human but would have been competing with them for resources.

The family tree of the genus Homo shows the relationship between the different species of humans over the last 2 million years and where they lived. (Photo Credit: Wikipedia)

So what caused humans make it and Neanderthals to die off? “One advantage modern humans may have had was that they were already trading over long distances,” says Dr. Pobiner. The social networking would have helped distribute food to areas that may not have had enough to eat, allowing more humans to survive during tougher times. Early modern humans also seemed to have a broader diet. While they definitely competed with Neanderthals for bigger game, they also ate small rodents and shellfish, resources that were easier to catch.

As climates changed and habitats shifted, the food that Neanderthals were used to eating just might not have been around anymore. “If your herd of reindeer isn’t where you are migrating this year and you are Neanderthal, you may be totally screwed,” explains Dr. Pobiner. “But you if you are a modern human, you might go down to the coast and collect enough food to get by.” Our ancestors may have been slightly more adaptable, which would have given them access to a wider range of resources, allowing humans to eek out a living and avoid extinction.  

Neanderthals today

Despite the differences in brain shape and facial features, Neanderthals were our closest relative, sharing 99.6% of their DNA with humans. Humans and Neanderthals have so much in common genetically, that they were able to have offspring together. “We know from genetics that modern humans actually interbred with Neanderthals when they encountered them in Europe and Asia,” says Dr. Pobiner.

This map shows the distribution of several different human species as well as when Homo sapiens arrived in various parts of the world. Modern humans got to Europe around 40,000 years ago, just as Neanderthals were on the decline. (Photo Credit: Wikipedia)

The last Neanderthals died out around 40,000 ago, but their genetic legacy lives on today. People today of non-African ancestry contain between 2-4% of Neanderthal DNA in their genome, proof that humans and Neanderthals not only co-existed but interacted as well. They have even contributed to our genome with traits that are useful even today. “It does seem that our Neanderthal genes do have some effect on our physiology, but we are just starting to understand what that might be,” says Dr. Pobiner. Traits like blood clotting, which would have been useful living in the rough and tumble Pleistocene, are now part of the human genome.  

So what lessons can we take from Neanderthals and their demise? “Neanderthals were really specialized,” says Dr. Pobiner. “When modern humans got to the areas where Neanderthals had been living happily for millennia, they were much more broad in their diet and technology. I think it’s been our flexibility and adaptability that allowed us to persist and thrive when Neanderthals went extinct. I think there’s a lesson to be learned there.”

Learn More:

  • Smithsonian Institution has a great interactive showing all species in the human family tree over the last 6 million years. Click on each species to learn about how they lived, what they looked like, and what fossils have been found.
  • Science Friday has a segment on the recently discovered Neanderthal cave art with Chris Standish from the University of Southampton and Christian Tryon from Harvard University.
  • Briana Pobiner sat on a panel on how early humans hunted and how their hunting habits affected the ecology around them. You can watch the video here.

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