genome

The Denisova Cave, nestled in the cold Altai Mountains of Siberia, continues to be one of the greatest treasures for world paleonthropology, since it brings together a large number of samples that enrich our history. One of the latest discoveries points to how they were organized and they lived Neanderthal populations in this remote Asian region. Something they have done from the genome of a Neanderthal man from 110,000 years ago. How it was done. The protagonist of this new research published in PNAS is a bone fragment named D17 that was found in these Asian mountains. But in light of previous studies, this team has managed to greatly refine the precision of sequencing, achieving an astonishing 37-fold coverage. This in genomics means that each “letter” of your DNA has been read 37 times, ensuring that the genome we are looking at is extraordinarily precise and not plagued by the degradation errors typical in such old samples. The result. When comparing the D17 genome With other fossils, scientists were in for a surprise, since this individual was directly related to another Neanderthal from the same cave, known as D5, who lived about 120,000 years ago. Despite being separated by 10,000 years of history, the two shared a close genetic link. This tells us something fundamental about Denisova Cave, as it was not a fixed settlement or permanent Neanderthal “city.” Rather, it acted as a recurring base camp or historical refuge to which closely related groups returned from generation to generation, maintaining an unusual regional genetic stability. Endogamy. Perhaps most important in this study is the evidence about how the population was structured. Here D17’s genome shows the genetic scars of living in a very empty world, as Neanderthal populations were tiny and incredibly dispersed. And it is no wonder because we are talking about groups of 50 individuals. This lack of other nearby groups with which to reproduce forced the Altai Neanderthals to crossing paths between close relatives for millennia. The problem with all this is that, being such small populations, the genetic changes were fixed quickly, separating them evolutionarily from other Neanderthal populations in Europe at an accelerated rate. A crossroads. If we started this article by mentioning the Denisova cave, logically we must also talk about the Denisovans, which is the other extinct human species discovered there. Here the new genomic analysis of D17 also confirms gene flow with this mysterious species. In both the D17 and older D5 genomes, scientists have found undeniable genetic traces of interbreeding with the Denisovans. This depicts the Denisova cave not only as a recurring refuge for isolated Neanderthal lineages, but as a true prehistoric crucible, a crossroads where two human species met, interacted and left a genetic legacy that today, through the most cutting-edge technology, we are managing to decipher. Images | freepik In Xataka | We had always thought of Neanderthals as “scavengers”: more and more studies point to the opposite