[Reading Science] Finding DNA Even in Ancient People's Urine

Remarkable Advances in DNA Restoration and Analysis Technology
Complete Genome Decoding of Over 10,000 Ancient Individuals
Leading to Various Discoveries Including Origins of Genetic Diseases

"DNA is found even in urine and dry soil from Neanderthals 40,000 years ago."

As gene (DNA) restoration and analysis technologies have advanced, research on the genomes of ancient humans has been increasing. This has led to fascinating discoveries about the origins of genetic diseases such as obesity, baldness, and diabetes, as well as infectious diseases, the living environments of ancient humans, and historical events, drawing significant attention.

Cannibalistic practices existed among Neanderthals.
Photo by AFP

The international academic journal Nature reported on the 24th (local time) that since the development of new DNA restoration and analysis techniques in 2010, the number of ancient individuals whose entire genome information has been decoded has exceeded 10,000 over the past 13 years. This cutting-edge genetic analysis technology began with the successful extraction and sequencing of the genome from the hair of a man who lived about 4,000 years ago in Greenland in 2010.

Previously, research on ancient human DNA was limited to about 16,500 mitochondrial pairs or short fragments of 3.1 billion base pairs. However, with the development of new DNA sequencing technology in 2010, it became possible to fully reconstruct ancient human genomes. At that time, the process was still labor-intensive and only feasible for ancient DNA samples with relatively good preservation. It took several years to restore the DNA of about ten individuals. However, since 2018, DNA sequencing technology and extraction methods have evolved once again. Now, genome sequencing of ancient humans can be done with much less effort and time. Instead of analyzing the entire genome of each individual, which is costly and time-consuming, a method sequencing and compiling one million DNA base sets with individual-specific characteristics is used. The abundance of DNA samples collected from relatively well-preserved ancient humans, i.e., those found after the end of the last Ice Age about 12,000 years ago, has also contributed to this research development.

So far, research on ancient human genome analysis has mainly focused on Western Eurasia, that is, Russia, Europe, and the Middle East (75%). However, there has been a relatively recent increase in research output from East Asia (8%), Oceania (2%), and Africa (3%). Particularly, genome analysis of ancient humans in Africa, where modern humans first inhabited, is increasing and attracting attention. However, about 80% of ancient human DNA analysis is primarily conducted at institutions such as Harvard Medical School in the United States, the University of Copenhagen in Denmark, and the Max Planck Institute in Germany, highlighting the need for activation in other countries and regions.

File photo. Photo by Korea Research Institute of Bioscience and Biotechnology

This ancient human genetic analysis technology has led to remarkable discoveries. According to the MIT Technology Review published in January, scientists can now detect minute traces of DNA not only from Neanderthal teeth or bones but even from soil containing urine. This was also the reason why Svante Paabo, a geneticist at the Max Planck Institute in Germany, was awarded the Nobel Prize in Physiology or Medicine last November. Paabo confirmed through ancient human DNA analysis that modern humans carry DNA from extinct Neanderthals and Denisovans. It was a revolution in paleogenetics that revealed the origins of genetic diseases and traits in modern humans. Human conditions such as obesity, diabetes, and baldness are related to genes inherited from Neanderthals, and some analyses suggest that the high mortality rate among Europeans during the recent COVID-19 pandemic was also linked to this.

Scientists are now using these advanced technologies to make various intriguing discoveries. For example, it was revealed that the ancient Greek army that fought on a battlefield in Sicily 2,500 years ago was composed of diverse ethnic groups. In India, the caste system has been weakened because, although 'pure blood' is highly valued, it was found that most of the population has mixed ancient human genes. Last year, a single gene mutation was discovered in medieval human remains that increased survival chances against the plague by up to 40%.