Diversification of land plants: insights from a family-level phylogenetic analysis
1 Division of Ecology and Evolution, Imperial College London, Silwood Park Campus, Ascot SL5 7PY, UK
2 Department of Systematic Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18 D, Uppsala 75236, Sweden
3 Department of Botany, Natural History Museum, London SW7 5BD, UK
4 Albrecht-von-Haller-Institute of Plant Sciences, Georg-August University, 37073, Göttingen, Germany
5 Royal Botanic Gardens, Kew, Richmond TW9 3DS, UK
BMC Evolutionary Biology 2011, 11:341 doi:10.1186/1471-2148-11-341Published: 21 November 2011
Some of the evolutionary history of land plants has been documented based on the fossil record and a few broad-scale phylogenetic analyses, especially focusing on angiosperms and ferns. Here, we reconstructed phylogenetic relationships among all 706 families of land plants using molecular data. We dated the phylogeny using multiple fossils and a molecular clock technique. Applying various tests of diversification that take into account topology, branch length, numbers of extant species as well as extinction, we evaluated diversification rates through time. We also compared these diversification profiles against the distribution of the climate modes of the Phanerozoic.
We found evidence for the radiations of ferns and mosses in the shadow of angiosperms coinciding with the rather warm Cretaceous global climate. In contrast, gymnosperms and liverworts show a signature of declining diversification rates during geological time periods of cool global climate.
This broad-scale phylogenetic analysis helps to reveal the successive waves of diversification that made up the diversity of land plants we see today. Both warm temperatures and wet climate may have been necessary for the rise of the diversity under a successive lineage replacement scenario.