Over the past decade, there has been no shortage of studies focused on the relationship between Neanderthals and our own species, Homo sapiens. Researchers have dug deep into the fossil record and our genomes to uncover how closely related we are to the Neanderthals, whether we interacted with them, and even whether our two species shared offspring.
But what about the Neanderthals themselves? We know that beginning around 400,000 years ago, they occupied over 3 million square miles of Europe and Western Asia, from Spain to Iraq. We know that they developed a unique tool technology and that they buried their dead. But what we really don’t know is how they compared to each other: were there in fact distinct Neanderthal sub-groups, shaped by the vastly different environments in which they lived? Or can they all be considered a single, genetically similar population? These questions are addressed in the most recent issue of PLoS One by anthropologists from the Université de la Méditerranée in France, using a method that is both unique and comprehensive.
This study is of interest not only because it attempts to understand Neanderthal diversity, but also because it utilized data from a various sources. First, the researchers collected data from the mitochondrial DNA sequences of 12 separate Neanderthal skeletons. These skeletons ranged in age from 29,000 to 100,000 years and were uncovered in various parts of the Neanderthal homeland, from Siberia to Spain. The researchers then took physical measurements of the skeletons themselves. Finally, they developed and ran complex computer simulations based on the genetic and skeletal data, in an attempt to discover the most likely scenario for how Neanderthals evolved and spread across much of Eurasia.
The authors concluded that the most likely scenario for how the Neanderthals populated Europe and Western Asia involves three Neanderthal sub-groups: one centered in Western Europe, another in Southern Europe, and the final group in the Levant/Western Asia. They propose that the Neanderthals within each of these sub-groups were more genetically — and perhaps physically — similar to each other than they were to members of another sub-group. This is contrary to the idea that the Neanderthals were a single, uniform population.
This result begs the question of cultural distinctions between the sub-groups. After all, if they were genetically and physically different from one another, it is entirely plausible that cultural differences, such as tool technologies, between the sub-groups also existed. The authors hope to understand cultural differences between Neanderthal sub-groups in the same way as they’ve understood genetic and physical differences. And, as more fossils are found and more DNA extracted, we will hopefully develop — with even more confidence — a clear picture on the origins and movements of Neanderthals.