Nobel Prize for Physiology and Medicine 2022
Complete Neanderthal genome sequencing by Swedish Geneticist Svante Pääbo:
The Nobel Prize in Physiology or Medicine 2022 has gone to Sweden's Svante Paabo for his work on human evolution.
Recently, the 2022 Nobel Prize for Physiology or Medicine has been awarded to Swedish geneticist Svante Pääbo for his research in the field of genomes of extinct hominins and human evolution.Svante Pääbo, a Swedish scientist who peered back into human history by retrieving genetic material from 40,000 year old bones, producing a complete Neanderthal genome and launching the field of ancient DNA studies, was awarded the Nobel Prize in Physiology or Medicine .
In 2021, the winners received almost 1million euros. Meanwhile, The New York Times have reported that the winner of the 2022 Nobel Peace Prize will receive a prize of 964,000 euros in October 2022.
Neanderthals were a separate species of human that populated Europe for hundreds of thousands of years until they went extinct 40,000 years ago.
The Prize committee said he achieved the seemingly impossible task of cracking the genetic code of one of our extinct relatives - Neanderthals.
He also performed the "sensational" feat of discovering the previously unknown relative - Denisovans.
His work helped explore our own evolutionary history and how humans spread around the planet.The Swedish geneticist's work gets to the heart of some of the most fundamental questions - where do we come from and what allowed us, Homo sapiens, to succeed while our relatives went extinct.
When he got the call saying he'd won. He told the BBC: "I was very surprised and overwhelmed, I had not expected this.Prof Paabo only heard the news when he was called by Thomas Perlmann, the secretary for the Nobel Committee for Physiology or Medicine.
"He was overwhelmed, he was speechless. Very happy," said Prof Perlmann.
In the1990s, research on working out the human genetic code was taking place at pace. But that relied on fresh samples of pristine DNA.
Prof Paabo's interest was in the old, degraded and contaminated genetic material from our ancestors. Many thought it was an impossible challenge. But he was, for the first time, able to sequence DNA from a 40,000-year-old piece of bone.
Those results showed that Neanderthals - who mostly lived in Europe and Western Asia - were distinct from both modern day humans and chimpanzees.
His work focused on hominins - the group of modern humans that includes us, Homo sapiens, but also our extinct relatives.
"By revealing genetic differences that distinguish all living humans from extinct hominins, his discoveries provide the basis for exploring what makes us uniquely human", the Nobel committee said.
BBC Podcast: Svante Paabo on the difference between us and Neanderthals
Further comparisons between Neanderthal DNA and humans from around the world showed their DNA was a closer match to humans coming from Europe or Asia.
This tells us that Homo sapiens had sex and children with Neanderthals after migrating out of Africa around 70,000 years ago.
And you can still see the legacy of that today. Between 1-4% of modern human DNA comes from our Neanderthal relatives and this even affects our body's ability to respond to infection.
The next seismic contribution to human origins came in 2008. Scientists had found a 40,000-year-old finger bone in the Denisova cave, in Siberia.
Prof Paabo was able to sequence a sample of DNA and the results showed it was a previously unknown hominin - known as "Denisovans".
And it turned out Homo sapiens also bred with Denisovans too. In parts of South East Asia up to 6% of people's DNA is Denisovan.
Some of this genetic inheritance helps the body cope with low levels of oxygen, aids survival at high altitudes and is found in present-day Tibetans.
Prof Paabo is seen as one of the founders of the scientific discipline of paleo genomics. He wins the 10 million Swedish kronor (£800,000) prize. He follows in the footsteps of his father, Sune Bergstrom, who won the same Nobel Prize in 1982.
His work shows there were already two distinct groups of hominins (Neanderthals and Denisovans) living in Eurasia when Homo sapiens spread from Africa.
Analysis suggests these now extinct populations were small and relatively inbred and may not have been able to compete with rapidly expanding modern humans.
Neanderthals (Homo neanderthalensis or Homo sapiens neanderthalensis) are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. While the "causes of Neanderthal disappearance about 40,000 years ago remain highly contested,' demographic factors such as small population size, inbreeding, and random fluctuations are considered probable factors. Other scholars have proposed competitive replacement, assimilation into the modern human genome (bred into extinction), great climatic change,diseases,
or a combination of these factors.
Neanderthals are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago.
Height: 1.6 – 1.7 m (5.3 to 5.7 fee in Male, Adult; 1.5 – 1.6 m (4.11-5.3 feet ) in Female, Adult
Extinction status: Extinct Encyclopedia of Life
Scientific name: Homo neanderthalensis
Family: Hominidae
Kingdom: Animalia
Order: Primates
Neanderthals are different species than us human being
Homosapiens.
The physical traits of Homo sapiens include a high and rounded ('globular') braincase, and a relatively narrow pelvis. Measurement of our braincase and pelvic shape can reliably separate a modern human from a Neanderthal - their fossils exhibit a longer, lower skull and a wider pelvis.
Neanderthals were actually very early humans (Primitive human beings)
Neanderthals were very early (archaic) humans who lived in Europe and Western Asia from about 400,000 i.e. 4 lakh years ago until they became extinct about 40,000 years ago.
Denisovans are another population of early humans who lived in Asia and were distantly related to Neanderthals.
East Asians seem to have the most Neanderthal DNA in their genomes, followed by those of European ancestry. Africans, long thought to have no Neanderthal DNA, were recently found to have genes from the hominins comprising around 0.3 percent of their genome.The researchers found that African individuals on average had significantly more Neanderthal DNA than previously thought—about 17 megabases (Mb) worth, or 0.3% of their genome.
The percentage of Neanderthal DNA in modern humans is zero or close to zero(0.3%) in people from African populations .
Neanderthals DNA is about 1 to 2 percent in people of European or Asian background.Most people have Neanderthal DNA, on average about 2.5 percent.
The researchers then calculated the probability that each stretch of DNA was inherited from a Neanderthal ancestor.
Neanderthals are known to contribute up to 1-4% of the genomes of non-African modern humans, depending on what region of the word your ancestors come from, and modern humans, homosapiens who lived about 40,000 years ago have been found to have up to 6-9% Neanderthal DNA (Fu et al., 2015).
Most scientists think that Neanderthals probably evolved in Europe from African ancestors. The consensus now is that modern humans and Neanderthals shared a common ancestor in Africa about 700,000 years ago. The ancestors of Neanderthals left Africa first, expanding to the Near East and then to Europe and Central Asia.
About Denisovan:
The scientific analysis suggested that Denisovans, much like Neanderthals, had a long, broad, and projecting face; larger nose; sloping forehead; protruding jaw; elongated and flattened skull; and wide chest and hips. However, the Denisovan tooth row was longer than that of Neanderthals and anatomically modern humans.
Denisovan species is the first fossil hominin identified as a new species based on its DNA alone. Denisovans are relatives of both modern humans and Neanderthals, and likely diverged from these lineages around 300,000 to 400,000 years(3 lakh to 4 lakh years) ago.
The Denisovans are the first ancient hominin species to be revealed by genes alone, not by fossil classification. While placed in the Homo genus, they have not yet been given a species classification as no physical description exists. They are named after the "Denisova Cave" in Russia where the first fossils were found.A decade ago, anthropologists shocked the world when they discovered a fossil pinkie bone from a then-unknown group of extinct humans in Siberia's Denisova Cave. The group was named "Denisovans" in its honor.
Denisovans are known to have lived in Siberia, Tibet, and Laos. The Xiahe mandible is the earliest recorded human presence on the Tibetan Plateau.
Influence of Neanderthal genes in modern human against COVID 19:
In fact, Paabo Svante published two papers, in 2020 and in 2021, on the possibility of genes from Neanderthals influencing the susceptibility of human beings to Covid-19. In the 2020 paper, published in Nature, he showed that one particular gene from the Neanderthals aggravated the risk of severe diseases among Covid patients.
However another study showed that Neanderthal inherited gene variant helps in protecting against severe COVID-19.
Remark:The genome sequencing of the Neanderthal genome is an important landmark in field of human genetics.It will help us in further understanding of extinction of Neanderthal and Denisovan, the primitive species of modern human.
Information compiled by: Dr. Bhairavsinh Raol
