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Population genetic analysis reveals a homoploid hybrid origin of Stephanomeria diegensis (Asteraceae)
Author(s) -
SHERMAN NATASHA A.,
BURKE JOHN M.
Publication year - 2009
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1111/j.1365-294x.2009.04349.x
Subject(s) - biology , evolutionary biology , introgression , population , genetic diversity , range (aeronautics) , genetics , gene , demography , sociology , materials science , composite material
Homoploid hybrid speciation has generally been viewed as a rare evolutionary phenomenon, with relatively few well‐documented cases in nature. Here, we investigate the origin of Stephanomeria diegensis , a diploid flowering plant species that has been proposed to have arisen as a result of hybridization between S. exigua and S. virgata . Across the range of S. diegensis , all individuals share a common chloroplast haplotype with S. virgata while showing a greater affinity for S. exigua in terms of nuclear genetic diversity. A prinicipal coordinates analysis (PCO) based on the nuclear data revealed that S. diegensis is most similar to each parent along different axes. Moreover, a Bayesian clustering analysis as well as a hybrid index‐based analysis showed evidence of mixed ancestry, with approximately two thirds of the S. diegensis nuclear genome derived from S. exigua . These results provide strong support for a homoploid hybrid origin of S. diegensis . Finally, contrary to the finding that homoploid hybrid species are typically multiply‐derived, our results were most consistent with a single origin of this species.