(Mis)remembering Neanderthals

I, a Homo sapiens, am the youngest of four. What a gift. Growing up was easy; it was all imitation. My sister – let’s call her N – was especially useful. I hoped to develop her perseverance – and rejected less favourable traits – a persistent lateness to meetings comes to mind. With time, our differences have become more marked, to the detriment of our relationship. Aided by my superior height, perhaps, I no longer feel the weight of N’s authority. The days of curiously eyeing her interactions and sartorial choices have been replaced by more critical observations. Sometimes, I struggle to recall whether we were ever truly close.

N is not an arbitrary name. My relationship to my sister bears an uncanny resemblance to that between Homo sapiens and Homo neanderthalensis. I arrived on this earth later than N, we come from the same parents, and we both call the Dordogne region of France home.

Discovered in the German Neander Valley in 1856, Neanderthals were blond or redheads with blue eyes. It is commonly known that they bore a protruding forehead and missing chin, thankfully not exhibited by my sister.  They and sapiens share Homo heidelbergensis as an ancestor. After splitting from heidelbergensis, Neanderthals opted for Eurasia as their birthplace and sapiens chose western Africa. This geographical chasm has translated to a cultural one, whereby we struggle to acknowledge a closeness with Neanderthals. At best, they are a hunched and grunting ancestor; at worst, a monkey-like creature.

What a disservice we do to a sibling. Neanderthals were not a more archaic version of ourselves but a coexisting species. It is perfectly plausible that our disorientated ancestors, upon arriving in southern Europe, crossed a lone group of Neanderthals and asked them for directions. The Neanderthals might have replied, as they possessed an identical voice box and all the neurological tools necessary to articulate language. Or they might have gazed at sapiens in helpless confusion, for their actual use of language remains unproven.

Our genetic makeup favours the first hypothesis; Europeans today carry approximately 3% of Neanderthalian genes, meaning interbreeding occurred. Archaeological findings also indicate exchanges between the species. Flint carving techniques developed by Neanderthals in the Moustier site of the Dordogne took hold with sapiens, to whom we attribute similar artefacts in the Middle East. Our widespread use of shoes, a piece of clothing first introduced by Neanderthals, also indicates a sharing of know-how.

Even the ability to create art, long heralded as a sapiens-only trait, was harnessed by Neanderthals. The Bruniquel cave of southern France, or ‘first museum of the world’, houses an impressive feat: four hundred stalagmites broken and rearranged into various structures. A more sophisticated design – a 130,000 year old eagle claw necklace – was found in Croatia.

With such creative flair and an expanding array of tools, Neanderthals were set up for success. Nothing could predict their disappearance some 40,000 years ago in the Iberic Peninsula. Or so it seemed…

Neanderthals’ comfortable lifestyle disguised a silent killer: isolation. Their population never exceeded 70,000 individuals, spread between Europe’s Atlantic coast and the Middle East. With such a large area to cover, it is unlikely that Neanderthal clans – comprising under 35 individuals – often interacted. Their natural preference for isolation likely further enhanced the frequency inbreeding within clans. The ensuing loss of genetic diversity might have lowered Neanderthals’ chances of survival, especially to illness. Such vulnerability resurfaced during the Covid-19 pandemic, when a certain Neanderthalian gene variant increased the risk of severe infection for their European carriers.

As most diseases leave no traces on bones, this explanation for extinction cannot be tested. For now, it seems an unlikely answer. Neanderthals disappeared over thousands of years, allowing ample time for their immune systems to adapt and improve. In any case, many diseases, such as influenza and smallpox, are zoonotic. Their appearance, coinciding with the domestication of animals, wreaked havoc long after Neanderthals’ disappearance.

We turn now to our sibling’s environment for answers. Neanderthals thrived during the Middle Palaeolithic (300,000 – 50,000 years). It is thought that they constructed their diets predominantly around hunting, perhaps developing a dependence on meat. When mammoths and woolly rhinoceroses became a rarity with the arrival of the last Ice Age (some 120,000 years ago), Neanderthals may have lacked the culinary adaptability necessary to survive. Sapiens, by contrast, developed a truer balance between hunting and gathering, using the latter to enhance their diet with various nuts, seeds and roots.

Dental analyses work in Neanderthals’ favour here. They show that Neanderthals were excellent cooks, willingly accompanying their grilled meats with seasonal vegetables and fish. This was a singularly adaptable species, familiar to the oscillations between glacial and interglacial periods, and armed against them, too: their stockier frames and larger thorax facilitated heat retention in cold climates. It remains unclear, then, why the last Ice Age should have been the end of the road.

This tug-of-war debate about Neanderthals’ extinction could continue. We have yet to examine more closely the climatic backdrop of the Neanderthal-sapiens transition or mention the domestication of wolves by sapiens. There is no need to delve into these hypotheses. Readers can now predict where they lead: argument, counter-argument, confusion.

Thankfully, one takeaway is clear. Just like my sister must tirelessly remind me of her five year seniority and greater lived experience, research on Neanderthals is positively humbling. We are not the first species to have cooked, created art or buried our dead. Others have done it before, and over longer periods (enter Homo erectus, but that’s a story for another time). There really is no need for the youngest of the bunch to insist on superior intelligence or evolutive advantages. Respect towards one’s elders is always more endearing than hubris.