Nobel Prize lecture: Svante Pääbo, Nobel Prize in Physiology or Medicine 2022 | Summary and Q&A

Summary

This video is the 2022 Nobel lecture in physiology or medicine, given by Professor Svante Pääbo, the Nobel laureate for his discoveries concerning the genomes of extinct hominins and human evolution. He discusses his journey in the field of ancient DNA research, including studying DNA from Egyptian mummies and Neanderthal and Denisovan genomes. He explains the contributions of Neanderthals and Denisovans to the genetic makeup of modern humans and discusses the implications of these findings for understanding human evolution and various aspects of human biology.

Questions & Answers

Q: What is the background of Professor Svante Pääbo's research?

Professor Svante Pääbo started his research career in the field of immunology, studying how the immune system recognizes infections. However, he became interested in ancient DNA and began exploring methods to extract DNA from historical specimens, such as Egyptian mummies. His diverse academic interests and his collaboration with other experts in the field allowed him to develop groundbreaking techniques for ancient DNA research.

Q: What were some of the challenges in studying ancient DNA?

Studying ancient DNA poses several technical challenges. The first challenge is the low amount of DNA present in ancient specimens, often on the order of thousands or millions of times less than in fresh tissues. In addition, ancient DNA is chemically modified and highly degraded, making it difficult to obtain long fragments of DNA. There is also a significant amount of contamination from microbial DNA, which needs to be distinguished from the target DNA. These challenges require extensive methods development to overcome.

Q: What were the major findings of Professor Svante Pääbo's research on Neanderthal genomes?

Through the sequencing of Neanderthal genomes, Professor Svante Pääbo and his team discovered that Neanderthals and modern humans share a common ancestor, and modern humans outside of Africa have inherited about 1-2% of their DNA from Neanderthals. This suggests that modern humans interbred with Neanderthals when they encountered each other, likely in the Middle East. It was also discovered that Neanderthals and Denisovans, another group of archaic hominins, interbred with each other as well as with modern humans. These findings provide insights into our genetic history and the evolutionary relationships between different human species.

Q: How did interbreeding with Neanderthals and Denisovans impact modern humans?

The interbreeding between modern humans and Neanderthals and Denisovans has had a lasting impact on the genetic makeup of modern humans. The introduction of archaic DNA into the modern human gene pool has influenced our physiology and health. For example, certain Neanderthal DNA variants have been associated with pain sensitivity and risk factors for preterm birth and severe disease. The ability to study these archaic genomes allows researchers to better understand the genetic basis of various traits and diseases in modern humans.

Q: How did Professor Svante Pääbo and his team study the function of Neanderthal DNA variants?

By comparing Neanderthal genomes to modern human genomes, Professor Svante Pääbo and his team were able to identify genetic variants that are specific to Neanderthals. They then studied the effects of these variants on specific genes and their associated biological functions. For example, they found that a Neanderthal variant of an ion channel gene is associated with increased pain sensitivity in modern humans. They also found that a Neanderthal variant of the progesterone receptor gene is associated with preterm birth and miscarriages. By understanding the functional impact of these genetic variants, researchers can gain insights into the biology of both Neanderthals and modern humans.

Q: What have we learned about the evolutionary relationships between modern humans, Neanderthals, and Denisovans?

Through the analysis of ancient DNA, it has been revealed that Neanderthals and Denisovans were closely related to each other and to modern humans. They shared a common ancestor in Africa and diverged into separate populations that evolved in different parts of Eurasia. Modern humans, on the other hand, evolved in Africa and later migrated out of Africa, encountering and interbreeding with Neanderthals and Denisovans along the way. The interbreeding between these different human species contributed to the genetic diversity of modern humans and shaped our evolutionary history.

Q: How did the interbreeding between different human species impact the genetic makeup of modern humans?

The interbreeding between different human species resulted in the transfer of genetic material between them, leading to the presence of archaic DNA in modern humans. This archaic DNA can still be found in specific regions of the genomes of individuals today. The presence of archaic DNA has provided new insights into human evolution and has allowed researchers to study the genetic basis of various traits and diseases in modern humans. It has also allowed for the reconstruction of the genetic history of different human populations and their interactions with each other.

Q: How does the study of ancient DNA contribute to our understanding of human evolution?

The study of ancient DNA provides a direct window into the past, allowing researchers to reconstruct the genetic history of different human species and their interactions. By comparing ancient genomes to modern genomes, researchers can identify genetic changes that occurred throughout human evolution. This includes changes that are specific to certain human species and changes that are unique to modern humans. These findings help us understand how different genetic variants have arisen and how they have shaped human evolution and the traits we see in modern humans.

Q: What are some of the implications of studying ancient DNA for medical research?

The study of ancient DNA has important implications for medical research. By comparing ancient genomes to modern genomes, researchers can identify genetic variants that have been associated with specific traits, diseases, and health conditions. This can help researchers understand the genetic basis of these conditions and develop targeted therapies. Additionally, studying the genetic history of different human populations can provide insights into the genetic diversity of modern humans and how it contributes to differences in disease susceptibility and treatment response among different populations.

Q: How does the study of ancient DNA contribute to our understanding of human biology?

The study of ancient DNA allows researchers to investigate the genetic basis of various aspects of human biology. By comparing ancient genomes to modern genomes, researchers can identify genetic variants that are associated with specific traits or biological functions. This can help us understand the evolutionary forces that have shaped human biology and how genetic variants influence traits and disease susceptibility. By studying the genetic makeup of our closest relatives, such as Neanderthals and Denisovans, we can gain insights into what makes us uniquely human and how we have evolved over time.

Takeaways

In summary, Professor Svante Pääbo's research on ancient DNA has provided valuable insights into human evolution and the genetic history of our species. Through the sequencing of Neanderthal and Denisovan genomes, he has shown that modern humans interbred with these archaic hominin groups, leading to the presence of archaic DNA in modern human populations. This interbreeding has had a lasting impact on the genetic makeup of modern humans, influencing our physiology, health, and susceptibility to diseases. By studying the functional effects of Neanderthal DNA variants, researchers can better understand the biology of both Neanderthals and modern humans. The study of ancient DNA is a powerful tool that contributes to our understanding of human evolution, genetic diversity, and the genetic basis of various traits and diseases.