Evolutionary persistence in Gunnera and the contribution of southern plant groups to the tropical Andes biodiversity hotspot
- Published
- Accepted
- Subject Areas
- Biogeography, Plant Science, Taxonomy
- Keywords
- diversification, climate change, Biogeography, Neotropics, Gondwana, species longevity
- Copyright
- © 2017 Bacon et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Evolutionary persistence in Gunnera and the contribution of southern plant groups to the tropical Andes biodiversity hotspot. PeerJ Preprints 5:e3330v1 https://doi.org/10.7287/peerj.preprints.3330v1
Abstract
Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes – the world’s “hottest” biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e. páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus Gunnera, a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments. Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby Gunnera tracks damp and boggy soils in cool habitats. Colonisation of the northern Andes is related to Quaternary climate change, with subsequent rapid diversification appearing to be driven by their ability to take advantage of environmental opportunities. This study demonstrates the composite origin of a mega-diverse biota.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Fig. S1
Figure S1. Morphological diversity of Gunnera: A. G. manicata (subgenus Panke), B. G. insignis (subgenus Panke), C. G. perpensa (subgenus Gunnera), D. G. magellanica (subgenus Misandra), E. G. dentata (subgenus Milligania), F. G. herteri (subgenus Ostenigunnera). Photos: A–B: A. Antonelli; C, E: I. Trift; D: I. Kärnefeldt, F: J.-T. Johansson.
Fig. S2
Figure S2. Traitgram of ancestral states of Gunnera climatic niche. Black lines correspond to a projection of the phylogenetic tree in a space defined by the bioclimatic variable mean annual temperature and annual precipitation.