The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical Andes
The evolutionary processes responsible for the extraordinary diversity in the middle elevation montane forests of the Tropical Andes (MMF; 1000–3500 m) remain poorly understood. It is not clear whether adaptive divergence, niche conservatism or geographical processes were the main contributors to th...
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| Format: | Article |
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MDPI AG
2021-08-01
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| Series: | Biology |
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| Online Access: | https://www.mdpi.com/2079-7737/10/9/825 |
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| author | Julien C. Vieu Darina Koubínová Jason R. Grant |
| author_facet | Julien C. Vieu Darina Koubínová Jason R. Grant |
| author_sort | Julien C. Vieu |
| collection | DOAJ |
| description | The evolutionary processes responsible for the extraordinary diversity in the middle elevation montane forests of the Tropical Andes (MMF; 1000–3500 m) remain poorly understood. It is not clear whether adaptive divergence, niche conservatism or geographical processes were the main contributors to the radiation of the respective lineages occurring there. We investigated the evolutionary history of plant lineages in the MMF. We used the vascular plant genus <i>Macrocarpaea</i> (Gentianaceae) as a model, as it consists of 118 morphologically diverse species, a majority of which are endemic to the MMF. We used a time-calibrated molecular phylogeny and morphological and climatic data to compare a set of evolutionary scenarios of various levels of complexity in a phylogenetic comparative framework. In this paper, we show that the hypothesis of adaptive radiation for <i>Macrocarpaea</i> in the MMF is unlikely. The genus remained confined to the upper montane forests (UMF > 1800 m) during more than a half of its evolutionary history, possibly due to evolutionary constraints. Later, coinciding with the beginning of the Pleistocene (around 2.58 Ma), a phylogenetically derived (recently branching) clade, here referred to as the <i>M. micrantha</i> clade (25 species), successfully colonized and radiated in the lower montane forests (LMF < 1800 m). This colonization was accompanied by the evolution of a new leaf phenotype that is unique to the species of the <i>M. micrantha</i> clade that likely represents an adaptation to life in this new environment (adaptive zone). Therefore, our results suggest that niche conservatism and geographical processes have dominated most of the diversification history of <i>Macrocarpaea</i>, but that a rare adaptive divergence event allowed a transition into a new adaptive zone and enabled progressive radiation in this zone through geographical processes. |
| first_indexed | 2024-03-10T07:53:18Z |
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| language | English |
| last_indexed | 2024-03-10T07:53:18Z |
| publishDate | 2021-08-01 |
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| series | Biology |
| spelling | doaj.art-713297fd18b04a67a12db6f51d8801ca2023-11-22T12:04:51ZengMDPI AGBiology2079-77372021-08-0110982510.3390/biology10090825The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical AndesJulien C. Vieu0Darina Koubínová1Jason R. Grant2Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, 2000 Neuchâtel, SwitzerlandInstitute of Biology, University of Neuchâtel, Rue Emile Argand 11, 2000 Neuchâtel, SwitzerlandInstitute of Biology, University of Neuchâtel, Rue Emile Argand 11, 2000 Neuchâtel, SwitzerlandThe evolutionary processes responsible for the extraordinary diversity in the middle elevation montane forests of the Tropical Andes (MMF; 1000–3500 m) remain poorly understood. It is not clear whether adaptive divergence, niche conservatism or geographical processes were the main contributors to the radiation of the respective lineages occurring there. We investigated the evolutionary history of plant lineages in the MMF. We used the vascular plant genus <i>Macrocarpaea</i> (Gentianaceae) as a model, as it consists of 118 morphologically diverse species, a majority of which are endemic to the MMF. We used a time-calibrated molecular phylogeny and morphological and climatic data to compare a set of evolutionary scenarios of various levels of complexity in a phylogenetic comparative framework. In this paper, we show that the hypothesis of adaptive radiation for <i>Macrocarpaea</i> in the MMF is unlikely. The genus remained confined to the upper montane forests (UMF > 1800 m) during more than a half of its evolutionary history, possibly due to evolutionary constraints. Later, coinciding with the beginning of the Pleistocene (around 2.58 Ma), a phylogenetically derived (recently branching) clade, here referred to as the <i>M. micrantha</i> clade (25 species), successfully colonized and radiated in the lower montane forests (LMF < 1800 m). This colonization was accompanied by the evolution of a new leaf phenotype that is unique to the species of the <i>M. micrantha</i> clade that likely represents an adaptation to life in this new environment (adaptive zone). Therefore, our results suggest that niche conservatism and geographical processes have dominated most of the diversification history of <i>Macrocarpaea</i>, but that a rare adaptive divergence event allowed a transition into a new adaptive zone and enabled progressive radiation in this zone through geographical processes.https://www.mdpi.com/2079-7737/10/9/825radiationniche conservatismadaptationtrait disparitymontane forestsAndes |
| spellingShingle | Julien C. Vieu Darina Koubínová Jason R. Grant The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical Andes Biology radiation niche conservatism adaptation trait disparity montane forests Andes |
| title | The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical Andes |
| title_full | The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical Andes |
| title_fullStr | The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical Andes |
| title_full_unstemmed | The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical Andes |
| title_short | The Evolution of Trait Disparity during the Radiation of the Plant Genus <i>Macrocarpaea</i> (Gentianaceae) in the Tropical Andes |
| title_sort | evolution of trait disparity during the radiation of the plant genus i macrocarpaea i gentianaceae in the tropical andes |
| topic | radiation niche conservatism adaptation trait disparity montane forests Andes |
| url | https://www.mdpi.com/2079-7737/10/9/825 |
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