The Neanderthal DNA enables scientists to pinpoint traits that distinguish modern humans from other hominins. The Nobel Assembly at the Karolinska Institutet in October awarded this year’s Nobel Prize in Physiology or Medicine to Svante Paabo “for his discoveries concerning the genomes of extinct hominins and human evolution”. Innovative research by Dr. Paabo aims to provide answers regarding human evolution. He was able to sequence the DNA of a type of human called Neanderthal, who lived and perished on the planet around 30,000 years ago. Denisova, a previously unknown hominid, was also discovered by him. (Members of the human ancestry known as hominins are extinct.) Following the journey out of Africa some 70,000 years ago, gene transfer occurred from these now-extinct hominins to Homo sapiens, according to Dr. Paabo’s findings, the Nobel Assembly pointed out. Svante Paabo’s Research According to the Nobel Assembly, Dr Paabo was intrigued by the prospect of analysing Neanderthal DNA, but it was not a simple task. Over time, DNA is prone to deterioration and chemical change. Only minute amounts of the Neanderthals’ DNA would have survived in the fossil record because they became extinct 30,000 years ago. In 1990, Dr Paabo was named professor at the University of Munich, where he carried on his investigation into the DNA of extinct human species. He decided to look at Neanderthal mitochondrial DNA at this moment. The “powerhouse of the cell,” or organelle known as the mitochondria, contains DNA. Thousands of copies of the mitochondrial genome exist despite being very small and only containing a small fraction of the genetic information in the cell. This increases the likelihood of its sequencing becoming successful. From a 40,000-year-old bone, the geneticist was able to sequence a portion of the mitochondrial DNA succesfully, demonstrating the genetic distinction between Neanderthals and modern humans, as well as chimpanzees. In 2010, a study by Dr Pääbo on a draught Neanderthal genome sequence was published. He described the examination of 21 Neanderthal bones from Croatia’s Vindija Caves by his team in the paper. Three bones were chosen for additional analysis after the bone powder from these specimens was analysed. Relevance for Today’s World Svante Paabo pioneering research has proven the significant impact of ancient gene sequences on the physiology of a modern day human being. One such example is that of the gene EPAS1, found in modern-day Tibetans and which helps in adaptability to higher altitude geographies. Another example is Neanderthal genes influencing how our immune system reacts to various pathogens. The work of Dr. Pääbo has in fact given an impetus to a completely new field of study – paleogenomics Dr Paabo is now considered one of the pioneers of the field of paleogenetics, and for good reason. His work has not just illuminated the past in new ways, but also pointed out how our Neanderthal ancestry affects the present. His team garnered widespread attention in 2021 when it revealed that patients with a specific Neanderthal variation on the third chromosome were more likely to experience severe COVID-19.
27 Oct 2022
Arya Zade
