Intercontinental Mediterranean disjunct mosses: morphological and molecular patterns.
This study focused on three species that occur disjunctly between western North America and the Mediterranean region of southern Europe, northern Africa, and western Asia, forming the so-called Madrean-Tethyan distribution pattern. Quantitative morphological characters were measured in New and Old World plants to find any subtle phenotypic differentiation between the disjunct populations. Sequences from the nuclear ribosomal internal transcribed spacer region were obtained from the same populations to assess differentiation at the molecular level and to compare molecular diversity with patterns of morphological similarity among plants. Little or no morphological differentiation existed between New and Old World plants in any of the species, but internal transcribed spacer (ITS) sequences revealed some phylogeographic structure. Patterns of morphological similarity in all three species were incongruent with phylogeographic structure revealed by sequence data. New World populations were more variable than Old World populations at the molecular level in the three species. Despite some evidence for differentiation between disjunct plants, no plausible mutation rate would date the divergence at ≥20 million years ago (MYA), as implied by the Madrean-Tethyan hypothesis. Recent long-distance dispersal is a more likely explanation for intercontinental disjunctions in these species.
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Related Subject Headings
- Evolutionary Biology
- 3108 Plant biology
- 3104 Evolutionary biology
- 3103 Ecology
- 0607 Plant Biology
- 0603 Evolutionary Biology
- 0602 Ecology
Citation
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Evolutionary Biology
- 3108 Plant biology
- 3104 Evolutionary biology
- 3103 Ecology
- 0607 Plant Biology
- 0603 Evolutionary Biology
- 0602 Ecology