By Cora Engelbrecht and Isabella Kwai
The Nobel Prize in Physiology or Medicine was awarded to Svante Pääbo, a Swedish geneticist, on Monday for his discoveries concerning the genomes of extinct hominins and human evolution.
It was the first of several prizes to be given over the next week. The Nobel Prizes, among the highest honors in science, recognize groundbreaking contributions in a variety of fields.
“Through his pioneering research, Svante Pääbo — this year’s Nobel Prize laureate in physiology or medicine — accomplished something seemingly impossible: sequencing the genome of the Neanderthal, an extinct relative of present-day humans,” the Nobel committee said in a statement.
“Pääbo’s discoveries have generated new understanding of our evolutionary history,” the statement said, adding that this research had helped establish the burgeoning science of “paleogenomics,” or the study of genetic material from ancient pathogens.
Nils-Göran Larsson, a professor in medical biochemistry for the Karolinska Institute in Solna, Sweden, said that Pääbo had used existing technology and his own methods to extract and analyze the ancient DNA.
“It was certainly considered to be impossible to recover DNA from 40,000-year-old bones,” Larsson said, adding later that his discoveries would “allow us to compare changes between contemporary Homo sapiens and ancient hominins. And this, over the years to come, will give us huge insights into human physiology.”
Anna Wedell, a professor of medical genetics at the Karolinska Institute, said that Pääbo’s findings “allow us to address one of the most fundamental questions of all: What makes us unique?”
By comparing and analyzing human genome sequences, Pääbo’s team discovered a previously unknown type of hominin, Denisova, the committee’s statement said, finding that gene flow occurred from the Denisova to Homo sapiens about 70,000 years ago. That information remained relevant, the statement said — for example, in helping to inform how human immune systems reacted to infections.
Pääbo, a Stockholm native, is the son of Sune Bergström, a biochemist who shared the Nobel Prize in Medicine in 1982.
When reached by telephone in Leipzig, Germany, Pääbo “was overwhelmed, he was speechless,” Thomas Perlmann, the secretary of the Nobel Assembly and the Nobel Committee, said in announcing the award.
Pääbo became enraptured with the possibility of using modern methods to study the genetic coding of Neanderthals early in his career, when he extracted the DNA from ancient mummies.
That experiment led him to become a pioneer in the swiftly evolving field of paleogenomics. He became a jigsaw master of human origins, developing and refining methods for recovering and analyzing DNA from ancient animal bones, such as those belonging to cave bears and ground sloths. But he was after something bigger.
“I longed to bring a new rigor to the study of human history by investigating DNA sequence variation in ancient humans,” he wrote in his 2014 memoir, “Neanderthal Man.”
In 2010, Pääbo achieved renown when he and his research team presented the first sequencing of the entire Neanderthal genome. It was a milestone for scientists, who had been puzzled by the fossils of Neanderthals since they were discovered in a German quarry in 1856.
Neanderthals, who lived up to 800,000 years ago in parts of Europe and Asia, had large brains and used sophisticated tools to hunt large mammals. Pääbo’s genome sequence helped settle many questions surrounding their relationship to modern-day humans.
“It’s a basic scientific discovery,” Larsson said. “It identities the very small and few differences between anatomically modern humans, Homo sapiens, and extinct hominins.”
The road to that discovery was punctuated by challenges. DNA in old bones becomes degraded and chemically damaged. Over time, the long coiled sequence breaks into fragments, making it vexingly difficult to create an accurate reconstruction of an extinct organism’s genes.
In her book “The Sixth Extinction,” science writer Elizabeth Kolbert likens the process to reassembling a “Manhattan telephone book from pages that have been put through a shredder, mixed with yesterday’s trash, and left to rot in a landfill.”