Various forms of the human species have been alive for hundreds of thousands of years before us. For the longest time, it was concluded that DNA breaks down over time and cannot be excreted from ancient fossils…until Svante Pääbo joined the research.
Pääbo, the leader of his research team, was able to extract fragments of DNA from the bones of Neanderthals and Denisovans. By extracting mitochondria outside the cell nuclei, Pääbo’s team was able to place the genetic information into the appropriate chromosome locations “by matching each fragment to similar sequences in human DNA” (Bower). As we learned in class, mitochondria contain circular chromosomes of DNA. Pääbo’s team was able to extract the mitochondria from the cell and then analyze the mtDNA in comparison to modern-day humans. With this process, he concluded that humans diverged from Neanderthals about 516,000 years ago.
Another way they were able to identify common genetic information in the present-day Homo sapiens was by putting DNA into a certain bacteria, which would then make copies of DNA fragments. With this effort, they were able to recover 29 out of the 35 genes that they were targeting.
These new techniques brought research teams to conclude that modern-day humans share similar genes to Denisovans such as ones that regulate brain size, help us adapt to altitude, or even make covid-19 more severe in some cases. The evidence around the commonalities of certain genes encourages the theory that at some point there was interbreeding between Homo lineage.
Pääbo’s findings have paved the way for groundbreaking research, identifying commonalities in evolution, and have helped us understand what makes humans so unique. This new state-of-the-art process can hopefully one day expand to multiple labs, research teams, and even countries. This would allow us to learn even more about our sophisticated past and maybe even some things about our future!