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An engine for global plant diversity: highest evolutionary turnover and emigration in the American tropics.

Antonelli A, Zizka A, Silvestro D, Scharn R, Cascales-Miñana B, Bacon CD - Front Genet (2015)

Bottom Line: Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms.In contrast, the outstanding species richness found today in the American tropics (the Neotropics), as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates.These results imply that the Neotropics have acted as an engine for global plant diversity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Environmental Sciences, University of Gothenburg Göteborg, Sweden ; Gothenburg Botanical Garden Göteborg, Sweden.

ABSTRACT
Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms) between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the latitudinal biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics), as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e., Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having "pumped out" more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity.

No MeSH data available.


Angiosperm phylogeny used for the range shift and diversification analyses, pruned from Zanne et al. (2014). The tree contains c. 22,600 terminal species and shows (A) the codification into each one of the continental-level regions defined in Figure 2, and (B) the codification of all species as tropical or non-tropical. Species in each of the regions defined are highly clustered phylogenetically according to Bayesian Tip-Significance testing (p < 0.001).
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Figure 4: Angiosperm phylogeny used for the range shift and diversification analyses, pruned from Zanne et al. (2014). The tree contains c. 22,600 terminal species and shows (A) the codification into each one of the continental-level regions defined in Figure 2, and (B) the codification of all species as tropical or non-tropical. Species in each of the regions defined are highly clustered phylogenetically according to Bayesian Tip-Significance testing (p < 0.001).

Mentions: Figure 4A shows the angiosperm phylogeny and the coding of each species as occurring in each of the four regions defined, whereas Figure 4B shows the coding in tropical and non-tropical regions. The Bayesian Tip-Significance testing indicated that species in all regions (Figure 2) are highly clustered phylogenetically (p<0.001 for all three statistical tests implemented in BaTS: parsimony score, association index and maximum exclusive single-state clade).


An engine for global plant diversity: highest evolutionary turnover and emigration in the American tropics.

Antonelli A, Zizka A, Silvestro D, Scharn R, Cascales-Miñana B, Bacon CD - Front Genet (2015)

Angiosperm phylogeny used for the range shift and diversification analyses, pruned from Zanne et al. (2014). The tree contains c. 22,600 terminal species and shows (A) the codification into each one of the continental-level regions defined in Figure 2, and (B) the codification of all species as tropical or non-tropical. Species in each of the regions defined are highly clustered phylogenetically according to Bayesian Tip-Significance testing (p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4389561&req=5

Figure 4: Angiosperm phylogeny used for the range shift and diversification analyses, pruned from Zanne et al. (2014). The tree contains c. 22,600 terminal species and shows (A) the codification into each one of the continental-level regions defined in Figure 2, and (B) the codification of all species as tropical or non-tropical. Species in each of the regions defined are highly clustered phylogenetically according to Bayesian Tip-Significance testing (p < 0.001).
Mentions: Figure 4A shows the angiosperm phylogeny and the coding of each species as occurring in each of the four regions defined, whereas Figure 4B shows the coding in tropical and non-tropical regions. The Bayesian Tip-Significance testing indicated that species in all regions (Figure 2) are highly clustered phylogenetically (p<0.001 for all three statistical tests implemented in BaTS: parsimony score, association index and maximum exclusive single-state clade).

Bottom Line: Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms.In contrast, the outstanding species richness found today in the American tropics (the Neotropics), as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates.These results imply that the Neotropics have acted as an engine for global plant diversity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Environmental Sciences, University of Gothenburg Göteborg, Sweden ; Gothenburg Botanical Garden Göteborg, Sweden.

ABSTRACT
Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms) between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the latitudinal biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics), as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e., Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having "pumped out" more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity.

No MeSH data available.