NEWS HIGHLIGHTS
Theme : Science & Technology
Paper : GS - 3
The 2022 Nobel Prize for Physiology or Medicine has been awarded by the Royal Swedish Academy of Sciences to Swedish geneticist Svante Pääbo for his research in the field of genomes of extinct hominins and human evolution.
Dr. Pääbo’s research has resulted in the rise of a new scientific discipline called Paleogenomics, which is the study and analysis of genes of ancient or extinct organisms.
TABLE OF CONTENT
- Context
- Svante Pääbo work
- Hominins
- What is the Breakthrough?
- Mitochondria
- Implications
Context :
The 2022 Nobel Prize for Physiology or Medicine has been awarded by the Royal Swedish Academy of Sciences to Swedish geneticist Svante Pääbo for his research in the field of genomes of extinct hominins and human evolution.
Svante Paabo work :
- Dr. Pääbo’s research has resulted in the rise of a new scientific discipline called Paleogenomics, which is the study and analysis of genes of ancient or extinct organisms.
- Dr. Pääbo was able to sequence the genome of Neanderthal, a species of humans that existed on the earth and went extinct around 30,000 to 40,000 years ago. They were a species or subspecies of archaic humans who lived in Eurasia.
- Dr. Pääbo also discovered Denisova. Denisovans or Denisova hominins are an extinct species or subspecies of archaic humans that ranged across Asia during the Lower and Middle Paleolithic. Denisovans are known from few physical remains and consequently, most of what is known about them comes from DNA evidence
Hominins :
- Hominins are the members of the zoological “tribe” Hominini (family Hominidae, order Primates), of which only one species exists today—Homo sapiens, or human beings.
- The term is used most often to refer to extinct members of the human lineage, some of which are now quite well known from fossil remains: Homo neanderthalensis (the Neanderthals), Homo erectus, Homo habilis, and various species of Australopithecus.
- Some characteristics that have distinguished hominins from other primates, living and extinct, are their erect posture, bipedal locomotion, larger brains, and behavioral characteristics such as specialized tool use and, in some cases, communication through language.
What is the Breakthrough?
- He found that “gene transfer had occurred from these now extinct hominins to Homo sapiens following the migration out of Africa around 70,000 years ago. This ancient gene flow has significant physiological relevance for present-day humans.
- Studying the DNA of Neanderthals was not an easy task, because over time, DNA tends to degrade and become chemically modified. Since Neanderthals became extinct 30,000 years ago, only trace amounts of their DNA would have been left in fossils, if any.
- So Dr Pääbo decided to study mitochondrial DNA from Neanderthals. In 2010, he published the first Neanderthal genome sequence. The geneticist was successful in sequencing a part of mitochondrial DNA from a 40,000-year-old bone.
Mitochondria :
-
Mitochondria, popularly called the powerhouse of the cell, is an organelle inside the cell that has its own DNA. Although the mitochondrial genome is small and only contains a fraction of genetic information in the cell, it is present in thousands of copies.
Implications :
- The Neanderthal genome allows researchers to identify features that are unique to present-day humans, relative to other hominins.
- DNA sequences from Neanderthals were also found to be more similar to sequences from contemporary humans originating from Europe or Asia than to contemporary humans originating from Africa, suggesting interbreeding between Neanderthals and Homo sapiens during their coexistence.
- Five present-day human genomes from different regions were sequenced and analyzed against the Neanderthal genome derived from the experiment. It was noted that the divergence of the Neanderthal genome to the human reference genome was greater than for any of the present-day human genomes that had been analyzed.