Nobel Prize 2022 in Medicine/Physiology

Nobel Prize 2022 in Medicine/Physiology

• Svante Pääbo, a Swedish biologist, just received the 2022 Nobel Prize for Physiology or Medicine for his work on the genomes of extinct hominins and human evolution.
• David Julius and Ardem Patapoutian, two American scientists, received the award in 2021 for their work identifying the receptors for temperature and touch.

What are Svante Paabo's Research's Key Highlights?

• Human development and the nearest living relatives of modern humans, the Neanderthals, evolved outside of Africa and lived in Europe and Western Asia from about 400,000 years ago until 30,000 years ago, when they went extinct. Homo sapiens first appeared in Africa about 300,000 years ago.
• Neanderthal genome sequencing: It has been discovered that ancient gene sequences from our extinct ancestors have an impact on the physiology of modern people.
• For instance, the Denisovan variant of the gene EPAS1, which is widespread among modern Tibetans, gives an advantage for life at high altitudes.
• Other instances include Neanderthal genes that influence how our immune systems react to various pathogens.
• Denisova's discovery: In the Denisova cave in southern Siberia, a fragment of a finger bone that was 40,000 years old was found in 2008.
• This bone's DNA was sequenced, which resulted in the identification of a previously unidentified hominin that was given the name Denisova.
• Coexistence of Different Human Species: The Neanderthals and Denisovans, who are the progenitors of modern humans, coexisted with them for around 20,000 years, during which time they not only interacted but also interbred.
• Approximately 1-4% of the genome in contemporary humans of European or Asian descent is Neanderthal-derived.
• Additionally, there had been gene exchange between Denisova and Homo sapiens. Populations in Melanesia and other regions of South East Asia, where people have up to 6% Denisova DNA, are where this association was initially discovered.

Novel Approach:

• Ancient DNA is extremely fragmented and contaminated with fungi and bacteria, making it difficult to amplify and sequence. DNA tends to deteriorate and undergo chemical modification over time.
• Pääbo made the decision to research Neanderthal mitochondrial DNA as a result.
• The organelle inside the cell known as the mitochondria, or the "powerhouse of the cell," has its own DNA.
• The mitochondrial genome exists in thousands of copies despite being tiny and only holding a small portion of the genetic material in the cell. This raises the likelihood of its sequencing being successful.
• Importance: The conceptual innovation is crucial to comprehending human evolution.
• Paleogenomics is the study and analysis of the genes of ancient or extinct creatures, and it has grown as a result of Dr. Pääbo's research.

Neanderthals: Who were they?

• Before going extinct some 30,000 years ago, Neanderthals, the closest relatives of modern humans, inhabited throughout Europe, West Asia, and even southern Siberia and the Middle East.

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