Thursday, February 27, 4:15pm, 9206
 
Tandy Warnow  
(Dept. of Computer Science University of Texas at Austin)
 
"New Algorithms for Reconstructing Evolutionary Trees"
 
Phylogenetic trees, also known as evolutionary trees,
model the evolution of biological species or genes
from a common ancestor. Reconstructing evolutionary
trees is a fundamental research problem in biology,
with applications to protein structure and function
prediction, pathway detection, sequence alignment,
drug design, etc. However, the reconstruction of
very large evolutionary trees is exceedingly difficult;
not only are the major optimization problems NP-hard,
but large real datasets of interest to the biological
community can take years of analysis without being
solved exactly. Furthermore, while polynomial time
methods for phylogeny reconstruction exist, our research
shows that the standard approaches (including the
popular Neighbor Joining method) may have "large
sequence length requirements".
In this talk I will present a new algorithmic approach,
called the "Disk-Covering Method (DCM)", for reconstructing
phylogenies. DCM is designed to be used in conjunction with a base
phylogenetic method. Our simulation studies show that
DCM, combined with the popular polynomial time
method Neighbor Joining, produces much more accurate
trees than Neighbor Joining by itself. Furthermore,
we can prove that DCM-NJ requires only polynomial
length sequences for accurate reconstruction of the
true tree with high probability.
 
The Colloquium is supported by generous
contributions from the CUNY Faculty Development Program, Bloomberg,
Information Builders, Inc., and Royal Philips Electronics.
 
 
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