Research in Professor Yang's Group at UCL

Our research is in the areas of molecular evolution, molecular systematics, and population genetics. We are more interested in computational biology than bioinformatics if such a distinction exists.

We develop statistical models of DNA or protein evolution to be used in reconstructing species phylogenies and in understanding the mechanisms of molecular sequence evolution. We make extensive use of maximum likelihood and Bayes methods, as well as computer simulation.

Real data analysis is also a major undertaking in the group, with detection of adaptive molecular evolution and comparative genomics to the focus. Those serves as the motivation and distraction for the more- theoretical work.

The research topics vary as members join and leave the group, but the following should give a good sample of current interests.

  • Bayes estimation of phylogenies and divergence dates.
    This involves developing Markov chain Monte Carlo algorithms to estimate molecular phylogenies and species divergence dates using Bayes statistics. More details about our research in this area can be found here.

  • Markov models of codon substitution and detection of adaptive molecular evolution.
    This involves development of models of codon substitution for comparative analysis of protein-coding DNA sequenecs. The nonsynonymous/synonymous substitution rate ratio provides a measure of selective pressure on the protein, which can be used to detect positive Darwinian selection acting on the protein sequence.

  • MCMC algorithms under coalescent models.
    This involves development of Bayes MCMC algorithms for analysing population samples from multiple loci with different data types (such as sequences and microsatellites), to account for population demographics models and migration.

  • Comparative analyses of viral and mammalian genomes.
    This project intends to perform genome-wide comparisons to identify changes in selective pressures after gene duplications or species divergence, or after viral transmission to a new host.

Return to Professor Yang's group web page.