Molecular evidence for multiple origins of woodiness and a New World biogeographic connection of the Macaronesian Island endemic Pericallis (Asteraceae: Senecioneae)

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 96; no. 24; pp. 13886 - 13891
• Main Authors: Panero, J.L, Francisco-Ortega, J, Jansen, R.K, Santos-Guerra, A
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 23.11.1999; National Acad Sciences; National Academy of Sciences
• Subjects: Asteraceae; Asteraceae - classification; Asteraceae - genetics; Atlantic Islands; Base Sequence; Biological Sciences; Biological taxonomies; Canaries; Coniferous forests; DNA, Plant; DNA, Ribosomal; Evolution; Evolution, Molecular; Flowers & plants; Forest ecology; genbank/af155895; genbank/af155896; genbank/af155897; genbank/af155898; genbank/af155900; genbank/af155961; genbank/af155962; genbank/af155963; genbank/af155964; genbank/af155965; genbank/af155966; genbank/af155967; genbank/af155968; genbank/af155969; genbank/af155970; genbank/af155971; genbank/af155972; genbank/af155973; genbank/af155974; genbank/af155975; genbank/af155976; genbank/af155977; genbank/af155978; genbank/af155979; genbank/af155980; genbank/af155981; genbank/af155982; genbank/af155983; genbank/af155984; Genera; habit; internal transcribed spacers; Islands; Lowland forests; Molecular Sequence Data; nucleotide sequences; Parsimony; Pericallis; Phylogeny; phytogeography; ribosomal DNA; rRNA; Senecioneae; spacer region; Taxa; woody plants; Azores; Canary Islands; Madeira Islands; Atlantic Islands; Madeira
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.96.24.13886

The prevalence of woody species in oceanic islands has attracted the attention of evolutionary biologists for more than a century. We used a phylogeny based on sequences of the internal-transcribed spacer region of nuclear ribosomal DNA to trace the evolution of woodiness in Pericallis (Asteraceae: Senecioneae), a genus endemic to the Macaronesian archipelagos of the Azores, Madeira, and Canaries. Our results show that woodiness in Pericallis originated independently at least twice in these islands, further weakening some previous hypotheses concerning the value of this character for tracing the continental ancestry of island endemics. The same data suggest that the origin of woodiness is correlated with ecological shifts from open to species-rich habitats and that the ancestor of Pericallis was an herbaceous species adapted to marginal habitats of the laurel forest. Our results also support Pericallis as closely related to New World genera of the tribe Senecioneae.