Systematics/Phytogeography / Taxonomie/ Section
Joly, Simon , McLenachan, Patricia A. , Lockhart, Peter .
A statistical approach for distinguishing hybridization and lineage sorting detects hybridization in New Zealand alpine Ranunculus.
Hybridization is widespread in nature. Yet, the problem of distinguishing hybridization from incomplete lineage sorting makes the extent and evolutionary significance of hybridization difficult to evaluate. Although some methods have been described in the past to differentiate these two evolutionary processes, they do not have general application. We present a novel parametric approach for statistically distinguishing hybridization from incomplete lineage sorting based on minimum genetic distances. It is based on the idea that the expected genetic distance between sequences from two species is smaller for some hybridization events than for incomplete lineage sorting scenarios. Using coalescent simulations and assuming a range of priors for divergence time and population size, predictive posterior distributions can be generated for the minimum inter-species distances expected under incomplete lineage sorting. If the observed distance between sequences from two species is smaller than its predicted distribution, incomplete lineage sorting can be rejected and hybridization inferred. We illustrate the approach and identify an ancient hybridization event in the Late Tertiary radiation of New Zealand alpine buttercups (Ranunculus).
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1 - Massey University, Allan Wilson Centre for Molecular Ecology and Evolution, Private Bag 11222, Palmerston North, New Zealand
2 - Massey University, Allan Wilson Centre For Molecular Ecology And Evolution, Private Bag 11 222, Palmerston North, New Zealand
incomplete lineage sorting
Non monophyletic species
Predictive posterior distribution.
Presentation Type: Oral Paper:Papers for Sections
Location: Room 5/Woodward
Date: Tuesday, July 29th, 2008
Time: 1:45 PM