Penn State University

PSU - Department of Statistics

Topic 1:

Estimating the Distribution of Amino Acids at the Origin of Life on Earth - Dennis Pearl

The recent discovery of water on the surface of Mars has presented the exciting possibility that amino acids may soon be discovered there as well.  If they are, which amino acids are most likely to be found and in what abundance?  In this project, students will study a collection of ancient enzymes using Bayesian Phylogenetics methodology to estimate the probability distribution of amino acids at the root of the tree of life. This work will involve a new stochastic model of molecular evolution specifically targeting the amino acid distribution at the root.  The results derived will then be compared to those from independent lines of inquiry on this topic that guess at the temporal order that the different amino acids have appeared on Earth, but do not arrive at an explicit probability distribution.  Students taking part in this project will advance their knowledge of probability, statistical inference, modeling of evolutionary processes, and computational issues in aligning amino acid sequences and drawing phylogenetic information from the alignment.