Ecological distributions, phenological isolation, and genetic structure in sympatric and parapatric populations of the<i>Larrea tridentata</i>polyploid complex

Laport, Robert G.; Minckley, Robert L.; Ramsey, Jennifer

doi:10.3732/ajb.1600105

Cited by 47 publications

(61 citation statements)

References 127 publications

(206 reference statements)

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“…Furthermore, in Galax urceolata complex, tetraploids have experienced niche contraction and divergence with respect to the ancestral wide niche of diploids (Gaynor et al ., ). Contrariwise, in cases where low ploidy cytotypes were unable to expand to occupy their full potential niche (Lowry & Lester, ), and/or multiple polyploid origins occur, the higher levels could experience niche expansion, as in Aster amellus (Münzbergová et al ., ), Claytonia perfoliata (McIntyre, ), Larrea tridentata (Laport et al ., ) or Senecio carniolicus (Sonnleitner et al ., ). These are dynamic systems with frequent coexistence in mixed‐ploidy populations (Kolář et al ., ), and where the apparent competitive superiority of the higher cytotypes may be enhanced by their recurrent polyploid formation and the alleged unfilled niches of lower ploidies.…”

Section: Discussionmentioning

confidence: 99%

Niche divergence and limits to expansion in the high polyploid Dianthus broteri complex

2019

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Summary Niche evolution in plant polyploids remains controversial and evidence for alternative patterns has been reported. Using the autopolyploid Dianthus broteri complex (2×, 4×, 6× and 12×) as a model, we aimed to integrate three scenarios – competitive exclusion, recurrent origins of cytotypes and niche filling – into a single framework of polyploid niche evolution. We hypothesized that high polyploids would tend to evolve towards extreme niches when low ploidy cytotypes have nearly filled the niche space. We used several ecoinformatics and phylogenetic comparative analyses to quantify differences in the ecological niche of each cytotype and to evaluate alternative models of niche evolution. Each cytotype in this complex occupied a distinct ecological niche. The distributions were mainly constrained by soil characteristics, temperature and drought stress imposed by the Mediterranean climate. Tetraploids had the highest niche breadth and overlap due to their multiple origins, whereas the higher ploidy cytotypes were found in different, restricted, nonoverlapping niches. Niche evolution analyses suggested a scenario with one niche optimum for each ploidy, including the two independent tetraploid lineages. Our results suggest that the fate of nascent polyploids could not be predicted without accounting for phylogenetic relatedness, recurrent origins or the niche occupied by ancestors.

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Section: Discussionmentioning

confidence: 99%

Niche divergence and limits to expansion in the high polyploid Dianthus broteri complex

2019

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“…This process can enhance the genetic diversity of a nascent polyploid population and potentially mitigate the consequences of inbreeding among a small number of autopolyploids (Bretagnolle & Thompson, 1995). The evolutionary importance of gene flow between diploids and tetraploids was noted by Stebbins (1971), and the contributions of intercytotype gene flow on genetic diversity have since been reported in autopolyploid Dactylorhiza maculata (Ståhlberg, 2009), Houstonia (Glennon & Church, 2015), and Larrea tridentata (Laport et al, 2016). Selection on new autopolyploids may therefore be complex, with potentially opposing pressures-complete reproductive isolation from diploid progenitors (through prezygotic or postzygotic mechanisms) will counteract the deleterious effects of MCE by preventing often-unsuccessful intercytotype mating, but maintaining reproductive overlap with diploids may provide the benefit of increased genetic diversity through rare introgression via unreduced gametes.…”

Section: Gene Flow Between Cytotypesmentioning

confidence: 95%

Pure polyploidy: Closing the gaps in autopolyploid research

Spoelhof

Soltis

2017

J of Sytematics Evolution

158

129

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Polyploidy (whole-genome duplication, WGD) is an integral feature of eukaryotic evolution with two main forms typically recognized, autopolyploidy and allopolyploidy. In plants, a growing body of research contradicts historical assumptions that autopolyploidy is both infrequent and inconsequential in comparison to allopolyploidy. However, the legacy of these assumptions still persists through a lack of research on central facets of autopolyploid evolution. This review highlights recent research that has significantly increased scientific understanding of autopolyploidy. Key advances include: 1) unreduced female gametes contribute disproportionally to polyploidization through the formation of triploids, 2) niche divergence in autopolyploids can occur immediately or gradually after WGD through a diverse set of mechanisms, but broad niche overlap is also common between diploids and autopolyploids, and 3) the degree of genomic and transcriptomic changes following WGD is lower in autopolyploids than allopolyploids, but is highly variable both within and between species in both types of polyploids. We discuss the implications of these and other recent findings, present promising systems for future research, and advocate for expanded research in diverse areas of autopolyploid evolution.

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“…Empirical support for this prediction is mixed (Vellend 2016), but more importantly this prediction does not consider that different mechanisms of speciation can cause differences in SPFD among regions. For example, sympatric speciation can occur via polyploidy in plants (Levin 1975, Husband andSchemske 2000) and this can result in polyploids occupying distinct niches from their diploid progenitors (e.g., Laport et al 2016, Ostevik et al 2016. In such a case, speciation in one region may concurrently increase species pool richness and SPFD ( Fig.…”

Section: Speciationmentioning

confidence: 99%

Integrating species traits into species pools

Spasojevic

Catano

LaManna

et al. 2018

Ecology

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Despite decades of research on the species-pool concept and the recent explosion of interest in trait-based frameworks in ecology and biogeography, surprisingly little is known about how spatial and temporal changes in species-pool functional diversity (SPFD) influence biodiversity and the processes underlying community assembly. Current trait-based frameworks focus primarily on community assembly from a static regional species pool, without considering how spatial or temporal variation in SPFD alters the relative importance of deterministic and stochastic assembly processes. Likewise, species-pool concepts primarily focus on how the number of species in the species pool influences local biodiversity. However, species pools with similar richness can vary substantially in functional-trait diversity, which can strongly influence community assembly and biodiversity responses to environmental change. Here, we integrate recent advances in community ecology, trait-based ecology, and biogeography to provide a more comprehensive framework that explicitly considers how variation in SPFD, among regions and within regions through time, influences the relative importance of community assembly processes and patterns of biodiversity. First, we provide a brief overview of the primary ecological and evolutionary processes that create differences in SPFD among regions and within regions through time. We then illustrate how SPFD may influence fundamental processes of local community assembly (dispersal, ecological drift, niche selection). Higher SPFD may increase the relative importance of deterministic community assembly when greater functional diversity in the species pool increases niche selection across environmental gradients. In contrast, lower SPFD may increase the relative importance of stochastic community assembly when high functional redundancy in the species pool increases the influence of dispersal history or ecological drift. Next, we outline experimental and observational approaches for testing the influence of SPFD on assembly processes and biodiversity. Finally, we highlight applications of this framework for restoration and conservation. This species-pool functional diversity framework has the potential to advance our understanding of how local- and regional-scale processes jointly influence patterns of biodiversity across biogeographic regions, changes in biodiversity within regions over time, and restoration outcomes and conservation efforts in ecosystems altered by environmental change.

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Ecological distributions, phenological isolation, and genetic structure in sympatric and parapatric populations of theLarrea tridentatapolyploid complex

Abstract: Diploid, tetraploid, and hexaploid cytotypes of L. tridentata are segregated by environmental distributions and flowering phenology in contact zones, with diploid and tetraploid populations having corresponding differences in genetic structure.

Cited by 47 publications

References 127 publications

Niche divergence and limits to expansion in the high polyploid Dianthus broteri complex

Niche divergence and limits to expansion in the high polyploid Dianthus broteri complex

Pure polyploidy: Closing the gaps in autopolyploid research

Integrating species traits into species pools

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