14 3 / 2024 // LEOPOLDINA / NEWS
“ I have got better at saying ‘ no ’“
Leopoldina Member , Svante Pääbo , will give the Christmas Lecture in Halle ( Saale )/ Germany
Svante Pääbo ML is Director at the Max Planck Institute for Evolutionary Anthropology in Leipzig / Germany . The Swedish molecular biologist and palaeogeneticist is considered the founder of palaeogenetics , which deals with the analysis of genetic samples of fossil and historical remains .
Since time immemorial , we have asked ourselves “ Where do we come from , who are we , where are we going ?” Svante Pääbo , Member of the Leopoldina since 2001 , has made a significant contribution to answering these questions and was awarded the Nobel Prize for Physiology or Medicine in 2022 for decoding the Neanderthal Genome .
For a long time , we thought that it was impossible to analyse the genetic material of a species that has been extinct for tens of thousands of years . But you didn ’ t let that deter you . What was your motivation ? Svante Pääbo : In the 1990s it became possible to determine some DNA sequences of cave bears and other animals that lived at the same time as the Neanderthals . This made it seem plausible that it would also be possible to decode the DNA sequences of Neanderthals , even though DNA decays over time .
Your initial focus was on mitochondrial DNA , which is easier to obtain . Pääbo : Yes , it was only possible to do that in the 1990s because it has several copies in each cell .
Image : Frank Vinken | MPI EVA
In 2010 your team almost completely decoded the Neanderthal Genome . What ultimately led to success ? Pääbo : Mitochondrial DNA represents only the maternal line of descent and only a small part of the genome . Techno logical advances , such as high-throughput sequencing and innovative bioinformatics , were crucial . We have also developed methods for working with small amounts of DNA and enriching the DNA . Another challenge was to detect contamination with human DNA and remove it in a targeted manner .
Apparently , early modern humans interbred with Neanderthals after our ancestors migrated out of Africa . Did you find this result surprising ? Pääbo : Yes , after analysing the mitochondrial DNA we tended to think that we would not find any Neanderthal genes in the human genome . However , our results showed us that we were wrong . About two per cent of our genome comes from the Neanderthals , and in Asians the percentage is significantly higher .
You have already achieved everything in terms of honours and success . What continues to motivate you ? What would you like to discover ? Pääbo : Our team is currently researching the functional effects of hominid DNA on modern humans in order to understand what advantages and disadvantages it offers . The immune system is of particular interest here , for example .
We are also studying the DNA of the Denisovans , a group of humans related to the Neanderthals . People from Oceania have about four per cent of this DNA in their genome . We want to find out what evolutionary advantages and disadvantages the DNA might have which has been preserved for such a long time . While archaic gene variants can help us in the fight against pathogens , it can also have disadvantages .
We are also particularly interested in gene variants which are involved in cognitive development . We are interested in when and how the variations that distinguish us from Neanderthals came about . I will talk about our efforts to study such variants in the Christmas lecture at the Leopoldina .
Your research has changed our understanding of our origins . What has changed for you since receiving the Nobel Prize ? Pääbo : I have got better at saying “ no ”. I decline invitations that are not primarily related to our research as politely as possible .
You have been a Member of the Leopoldina since 2001 . What does this mean to you ? Pääbo : I appreciate the policy advice issued by the Leopoldina , even though I have never been actively involved in this myself .
■ THE INTERVIEW WAS CONDUCTED BY HANNELORE GIESSEN