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Proc Natl Acad Sci U S A. Jul 23, 1996; 93(15): 7743–7748.
PMCID: PMC38818

A common origin for woody Sonchus and five related genera in the Macaronesian islands: molecular evidence for extensive radiation.

Abstract

Woody Sonchus and five related genera (Babcockia, Taeckholmia, Sventenia, Lactucosonchus, and Prenanthes) of the Macaronesian islands have been regarded as an outstanding example of adaptive radiation in angiosperms. Internal transcribed spacer region of the nuclear rDNA (ITS) sequences were used to demonstrate that, despite the extensive morphological and ecological diversity of the plants, the entire alliance in insular Macaronesia has a common origin. The sequence data place Lactucosonchus as sister group to the remainder of the alliance and also indicate that four related genera are in turn sister groups to subg. Dendrosonchus and Taeckholmia. This implies that the woody members of Sonchus were derived from an ancestor similar to allied genera now present on the Canary Islands. It is also evident that the alliance probably occurred in the Canary Islands during the late Miocene or early Pliocene. A rapid radiation of major lineages in the alliance is consistent with an unresolved polytomy near the base and low ITS sequence divergence. Increase of woodiness is concordant with other insular endemics and refutes the relictural nature of woody Sonchus in the Macaronesian islands.

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  • Baldwin BG, Kyhos DW, Dvorak J, Carr GD. Chloroplast DNA evidence for a North American origin of the Hawaiian silversword alliance (Asteraceae). Proc Natl Acad Sci U S A. 1991 Mar 1;88(5):1840–1843. [PMC free article] [PubMed]
  • Givnish TJ, Sytsma KJ, Smith JF, Hahn WJ. Thorn-like prickles and heterophylly in Cyanea: adaptations to extinct avian browsers on Hawaii? Proc Natl Acad Sci U S A. 1994 Mar 29;91(7):2810–2814. [PMC free article] [PubMed]
  • Gunnersen JM, Crawford RJ, Tregear GW. Expression of the relaxin gene in rat tissues. Mol Cell Endocrinol. 1995 Apr 28;110(1-2):55–64. [PubMed]
  • Baldwin BG. Phylogenetic utility of the internal transcribed spacers of nuclear ribosomal DNA in plants: an example from the compositae. Mol Phylogenet Evol. 1992 Mar;1(1):3–16. [PubMed]
  • Li WH, Tanimura M. The molecular clock runs more slowly in man than in apes and monkeys. Nature. 1987 Mar 5;326(6108):93–96. [PubMed]
  • Wu CI, Li WH. Evidence for higher rates of nucleotide substitution in rodents than in man. Proc Natl Acad Sci U S A. 1985 Mar;82(6):1741–1745. [PMC free article] [PubMed]

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