Since the first Neanderthal remains were discovered in a German quarry in 1856, paleontologists have struggled to understand what separated those primitive humans from modern ones, and how did they relate to us?

Svante Pääbo, a scientist of Swedish descent whose decades-long efforts to extract DNA from 40,000-year-old remains culminated in the publication of the Neanderthal genome in 2010, was given the Nobel Prize in Physiology or Medicine

The Nobel committee stated on Monday that Dr. Pääbo's enduring obsession—how to recover and interpret ancient genetic material—seemed destined to fail in the face of frustrating technological challenges. Chemical damage to ancient DNA causes it to typically only be found in extremely small amounts in old samples. It can be easily contaminated by the DNA of the scientists handling it, making it challenging to discriminate between ancient and current genes. Additionally, bacteria can leave DNA in fossils, pushing researchers to learn how to identify those genes.

But Dr. Pääbo made use of the most recent DNA sequencing technologies. He managed the diplomatic complexities of collecting fossilized bone fragments from other nations when he ran out of bone. He created "clean rooms," laboratories with strict cleanliness requirements that shielded specimens from contamination. He and his team then utilized advanced statistical tools to identify the current genetic contamination after unraveling the millions of DNA fragments in the fossils. Such a discovery allowed us to examine alterations between modern Homo sapiens and prehistoric hominids thanks to Dr. Pääbo's exacting standards, bioinformatic techniques, and chemical cunning.

And this will provide us with a great deal of knowledge into human physiology throughout the coming years. The study contributed to the discovery that contemporary humans and Neanderthals have a 600,000-year-old common ancestor. Genetic proof that modern humans and Neanderthals interbred throughout times of coexistence was also discovered by Dr. Pääbo and his team. Neanderthals inhabited much of Europe before going extinct some 30,000 years ago for reasons that are still hotly contested. Before traveling to Europe and Asia, the progenitors of modern humans evolved in Africa. There, they interbred with more primitive human forms and acquired genetic alterations that improved their odds of surviving in unfamiliar circumstances. These included gene variations that affected the immune system's reaction to infection and enhanced the capacity to survive at high elevations.

However, despite Dr. Pääbo's ground-breaking discoveries, the most important query — what distinguishes modern humans from other species? — continues to be a mystery. His research revealed genetic variations that are present in current people but not in Neanderthals, providing a kind of blueprint for the mutations that put modern humans apart from Neanderthals and explain their radical departure from their culture and behavior. But it's still difficult to connect such mutations to modern human characteristics like the ability to create figurative art, complex cultures, massive social networks, and cutting-edge innovation.