Revisiting the question how many characters are needed to reconstruct the true tree

14 mins 18 secs, 95.69 MB, WebM 640x360, 29.97 fps, 44100 Hz, 913.66 kbits/sec

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Description:	Fischer, M (CIBIV, Vienna) Monday 20 June 2011, 11:50-12:10

Created:

2011-06-23 16:45

Collection:

Phylogenetics

Publisher:

Isaac Newton Institute

Fischer, M

Language:

eng (English)

Credits:

Author:	Fischer, M
Producer:	Steve Greenham


Abstract:	The question of how many sequence sites are required to recover the evolutionary relationship of the underlying species accurately is important for phylogeneticists. It is known that a particularly challenging problem for phylogenetic methods arises when a rapid divergence event occurred in the distant past, which leads to long pending branches and a short internal branch in the corresponding phylogenetic tree. While most previous approaches tackling this problem considered only 2-state models, we investigate the scenario based on all four (DNA) character states. Particularly, we analyze a binary unrooted 4-taxon phylogenetic tree with a short interior edge and pending edges of multiple length. In my talk, I will present an optimal branch length of the interior edge in this case and I will explain how many characters are at least needed to reconstruct the 'true' tree.

Abstract:

The question of how many sequence sites are required to recover the evolutionary relationship of the underlying species accurately is important for phylogeneticists. It is known that a particularly challenging problem for phylogenetic methods arises when a rapid divergence event occurred in the distant past, which leads to long pending branches and a short internal branch in the corresponding phylogenetic tree.
While most previous approaches tackling this problem considered only 2-state models, we investigate the scenario based on all four (DNA) character states. Particularly, we analyze a binary unrooted 4-taxon phylogenetic tree with a short interior edge and pending edges of multiple length. In my talk, I will present an optimal branch length of the interior edge in this case and I will explain how many characters are at least needed to reconstruct the 'true' tree.

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