Phylogenomics: Gene Duplication, Unrecognized Paralogy and Outgroup Choice
2009

Choosing Outgroups in Phylogenetic Analysis

publication Evidence: moderate

Author Information

Author(s): Roy Scott William

Primary Institution: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health

Hypothesis

How should outgroups be chosen to reduce non-species tree signal in phylogenetic analysis?

Conclusion

Using closely-related outgroups can minimize conflicting signals from gene duplication in phylogenetic analysis.

Supporting Evidence

  • When a single outgroup is used, the degree of non-species tree signal is minimized by using a maximally closely related outgroup.
  • Using two outgroups can help detect gene trees that contradict known species relationships.
  • Gene duplication can lead to gene trees that do not reflect the actual species tree.

Takeaway

When scientists want to understand how different species are related, they can use other species as 'outgroups' to help. Choosing the right outgroup can make their conclusions more accurate.

Methodology

The study analyzes the effects of gene duplication and loss on phylogenetic trees using theoretical models.

Limitations

The study only considers relationships among three species and uses a limited number of outgroups.

Digital Object Identifier (DOI)

10.1371/journal.pone.0004568

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