Dating dispersal and radiation in the gymnosperm gnetum

Posted by / 18-Jul-2017 18:14

Twenty-eight taxa; 4,367 and 1,025 bases; ML: –ln likelihood = 24,645.044 (ti/tv = 2.137, inv sites = 0.427, gamma = 0.685); MP: 3 trees at 3,583 steps (CI = 0.49; RI = 0.67).ML/MP bootstraps also given for two key nodes (in brackets) after deletion of long-branch A (17 taxa, 1,283 and 244 bases): ML: -ln likelihood = 5,678.420 (ti/tv = 1.774, inv sites = 0.431, gamma = 1.836; MP: 1 tree at 777 steps (CI = 0.621; RI = 0.723).Analyses with outgroups screened to avoid long branches consistently identify all gymnosperms as a monophyletic sister group to angiosperms.Combined three- and four-gene rooted analyses resolve the branching order for the remaining major groups—cycads separate from other gymnosperms first, followed by and then (Gnetales Pinaceae) sister to a monophyletic group with all other conifer families.There are many reasons why a cookie could not be set correctly.Below are the most common reasons: This site uses cookies to improve performance by remembering that you are logged in when you go from page to page.The origin of angiosperms has long been considered a fundamental mystery of plant evolution (1–4), and until recently, the main data available for addressing this question came from morphological and anatomical analysis of living and fossil species, with subsequent cladistic analysis.

Efforts to resolve Darwin's “abominable mystery”—the origin of angiosperms—have led to the conclusion that Gnetales and various fossil groups are sister to angiosperms, forming the “anthophytes.” Morphological homologies, however, are difficult to interpret, and molecular data have not provided clear resolution of relationships among major groups of seed plants.

We also considered certain fossil Mesozoic conifer cones, which shed further light on the evolution of the cupressaceous cone.

The evidence from these various genera strongly indicates that recently reconstructed phylogenies of gymnosperms based on molecular evidence from extant taxa do not reflect the evolution that actually happened.

Some species have been proposed to have been the first plants to be insect-pollinated as their fossils occur in association with extinct pollinating scorpionflies.

Molecular phylogenies based on nuclear and plastid sequences from most of the species indicate hybridization among some of the Southeast Asian species.

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We introduce two sequence data sets from slowly evolving mitochondrial genes, A also strongly support a gnetophyte–conifer grouping.

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