Research

A central research focus of mine is estimating a population's demography using genetic data. Direct observations are often costly and time consuming, thus having methods that analyze genetic data can give valuable new insights into current and past population structure.

Ancient DNA of Humans

In the last decade, a new fascinating application of such techniques has emerged. It has become feasible to extract and analyze DNA from ancient skeletal material (aDNA). A new field, termed archaeogenetics, has produced much new insight into long-standing questions about connectivity and migrations of past human cultures. This discipline connects two big personal interests of mine, human history and population genetics. I decided to establish a research career in this field, and in 2021 I started a position as a group leader in the Department of Archaeogenetics at the Max Planck Institute for Evolutionary Anthropology in Leipzig, a leading center for sequencing and analysing human aDNA.

My work on aDNA focusses on two topics:

• Population Genetic analysis of aDNA data. By studying DNA of peoples who lived many generations ago, one can learn about past population history, for instance migrations, admixtures and population turnovers. Archaeogenetics has become an exciting new tool to learn about human population history.
• Creating new computational tools for studying aDNA data. Particularly, I am working on pushing powerful haplotype based methods to the low coverage DNA data typical for aDNA.
  
  

Demographic Inference using shared haplotypes

I am particularly interested in utilizing the power of IBD segments for demographic inference. These blocks are the genomic signposts of recent genealogical connections between two individuals; they are co-inherited identically from a (very) recent common ancestor (hence Identical by Decent - IBD). Based on population genetic arguments, I envision that IBD segments can be an ideal ressource to infer key recent demographic parameters such as rates of mobility, connectivity and population size trajectories.

Method to infer IBD segments are already commonly applied to modern DNA, e.g. IBD blocks are widely used in personal genomics to detect up to third degree cousins. However, the low-coverage regime typical of aDNA data is not accessible with standard IBD detection approaches. My group and I have been working on bringing powerful IBD methods also to aDNA:

• Detecting IBD in aDNA with specifically developed and fine-tuned methods.
• Turning IBD segments inferred in aDNA into demographic estimates. For instance, one needs to develop new tools for time series data.

This progress allows us to address key questions about the human past in a completely new way.