“Understanding the basis of ageing in somatic evolution”

Prof. Michael Lässig

Prof. Michael Lässig studied physics in Munich, Rome and Santa Barbara (CA). He obtained his PhD in Theoretical Physics from University of California, Santa ­Barbara, in 1991. He is an internationally recognized expert on equilibrium and nonequilibrium statistical physics. In the last ten years, he has focused on research at the interface of statistical biophysics and molecular evolution. Since 1999, he has held his current position as Professor of Physics at the University of Cologne and since 2007, he is Speaker of the Collaborative Research Center Molecular Basis of Evolutionary Innovations. Lässig currently serves as deputy coordinator responsible for the theory projects of the Sybacol initiative.  

Research interests

  • Regulatory networks
  • Molecular evolution and population genetics
  • Biophysics 

Previous scientific achievements

Michael Lässig has used biophysical models to explain how the regulation of genes has evolved and has also made ­significant contributions to the statistics of genomic sequences and of complex networks. In collaboration with Johannes Berg, he has developed methods to compare networks and to identify their biologically relevant features. Finally, he is also known for his seminal work on the theory of biological evolution.

Current projects

To determine the interactions between ageing-related path­ways, the Lässig group in collaboration with the experimental groups is analysing time-series expression data to identify regulatory pathways affecting the process of ageing and their mutual interactions.

To better understand somatic evolution over the lifespan of an individual, this group is also quantifying the complex ­mutational processes characterizing the ageing process. These processes include deleterious mutations affecting, e.g. mitochondrial function, as well as beneficial mutations that prolong lifespan. The ultimate aim of these studies is to produce a clearer picture on the effects of multiple mutations on ageing.


Selected Publications

Perfeito, L., Ghozzi, S., Berg, J., Schnetz, K., and Lassig, M.: Nonlinear fitness landscape of a molecular pathway. PLoS Genet. (2011); 7(7): e1002160.

Mustonen, V., and Lassig, M.: Fitness flux and ubiquity of adaptive evolution. Proc Natl Acad Sci U S A. (2010); 107(9): 4248-4253.

Mustonen, V., Kinney, J., Callan, C.G., Jr., and Lassig, M.: Energy-dependent fitness: a quantitative model for the evolution of yeast transcription factor binding sites. Proc Natl Acad Sci U S A. (2008); 105(34): 12376-12381.

Mustonen, V., and Lassig, M.: Adaptations to fluctuating selection in Drosophila. Proc Natl Acad Sci U S A. (2007); 104(7): 2277-2282.

Mustonen, V., and Lassig, M.: Evolutionary population genetics of promoters: predicting binding sites and functional phylogenies. Proc Natl Acad Sci U S A. (2005); 102(44): 15936-15941.

Organisation / Institute
Institute for Theoretical Physics,
University of Cologne

Prof. Michael Lässig
Institute for Theoretical Physics
University of Cologne
Zülpicher Str. 77
50937 Köln, Germany


This tree shows the evolution of the influenza virus, a process with multiple beneficial and deleterious mutations. Can we think of the ageing process in a comparable way?