Molecular Systematic Analysis Reveals Cryptic Tertiary Diversification of a Widespread Tropical Rain Forest Tree

• Published in: The American naturalist 2003-12, Vol.162 (6), p.691-703
• Main Authors: Dick, Christopher W., Abdul‐Salim, Kobinah, Bermingham, Eldredge
• Format: Article
• Language: English
• Subjects: Africa; Base Sequence; Bayes Theorem; Biodiversity; Biological taxonomies; Caribbean Region; Clusiaceae - genetics; Dispersal; DNA, Ribosomal - genetics; Evolution, Molecular; Forest trees; Fossils; Genera; Genetic Variation; Geography; Haplotypes; Haplotypes - genetics; Internal transcribed spacers; Molecular Sequence Data; Nucleotides; Phylogenetics; Phylogeny; Rainforests; rRNA; Sequence Analysis, DNA; South America; Symphonia globulifera; Trees; Tropical rain forests
• ISSN: 0003-0147; 1537-5323
• DOI: 10.1086/379795

The broad geographic range of many Neotropical rain forest tree species implies excellent dispersal abilities or range establishment that preceded the formation of current dispersal barriers. In order to initiate historical analyses of such widespread Neotropical trees, we sequenced the nuclear ribosomal spacer (ITS) region ofSymphonia globuliferaL. f. (Clusiaceae) from populations spanning the Neotropics and western Africa. This rain forest tree has left unmistakable Miocene fossils in Mesoamerica (15.5–18.2 Ma) and in South America (∼15 Ma). Although marine dispersal ofS. globuliferais considered improbable, our study establishes three marine dispersal events leading to the colonization of Mesoamerica, the Amazon basin, and the West Indies, thus supporting the paleontological data. Our phylogeographic analysis revealed the spatial extent of the three NeotropicalS. globuliferaclades, which represent trans‐Andes ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\mathrm{Mesoamerica}\,+\mathrm{west}\,$ \end{document} Ecuador), cis‐Andes ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\mathrm{Amazonia}\,+\mathrm{Guiana}\,$ \end{document} ), and the West Indies. Strong phylogeographic structure found among trans‐Andean populations ofS. globuliferastands in contrast to an absence of ITS nucleotide variation across the Amazon basin and indicates profound regional differences in the demographic history of this rain forest tree. Drawing from these results, we provide a historical biogeographic hypothesis to a