A little over 20 years ago, scientists figured out how to isolate the DNA of prehistoric humans from fossils, allowing them to study ancient genetic material and learn more about the development of our species. In 2022, a team from the Planck Institute in Leipzig, Germany followed in the footsteps of that development by discovering Neanderthal DNA in a cave in Belgium—a cave completely devoid of Neanderthal fossils. The scientists needed only scraps of DNA found in soil samples to characterize it as Neanderthal and study it in detail. As The Guardian reports, this technique represents a significant advance in the field of evolutionary biology.
By studying ancient DNA, scientists can uncover otherwise unknowable revelations about our ancestors and other human species. For example, by identifying genetic markers in DNA from the first farmers, we know that a distinct population known as basal Eurasians lived in the Middle East around 15,000 years ago, even without any physical evidence of their existence. DNA analysis has similarly shown that while much of the human genome is interspersed with Neanderthal DNA, there are genes in which no Neanderthal traces can be found, meaning the people who inherited the Neanderthal versions were stuck with some yet-unknown evolutionary disadvantage and died out as a result.
There remain huge gaps in our understanding of human evolution and archaic history, the mysterious disadvantage of Neanderthal genes being just one example. The ability to rigorously analyze small amounts of DNA opens a world of discoveries that bones and fossils could never have revealed, but which we are only beginning to shed light onto. Further progress using these techniques will teach us more not only about how early humans migrated and interacted, but how exactly they evolved, and likewise how they gave rise to the humans that walk the planet today.