1
|
Liu K, Li E, Cui X, Wang Y, Xu C, Suo Z, Dong W, Zhang Z. Key innovations and niche variation promoted rapid diversification of the widespread Juniperus (Cupressaceae). Commun Biol 2024; 7:1002. [PMID: 39152250 PMCID: PMC11329744 DOI: 10.1038/s42003-024-06687-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 08/06/2024] [Indexed: 08/19/2024] Open
Abstract
The processes of forming lineages undergoing widespread radiations remain a knowledge gap that is fundamental to our understanding of the geographic distributions of species. Although early studies emphasized the importance of dispersal ability and historical migration events, key innovations that promote rapid diversification and/or adaptation to new habitats may also strongly influence distribution ranges. Juniperus is the second largest genus of conifers and is widely distributed throughout the Northern Hemisphere. Here, we used phylogenetic, phenotypic, and climatic data to investigate the contributions of these processes to the wide distribution and rapid diversification of Juniperus. Combining a time-scaled phylogeny and macroevolutionary theory, we show that the key innovations of berry-like seed cones and dioecy promoted the rapid diversification of Juniperus and that increased dispersal ability promoted allopatric speciation. Ecological niches had significant divergence among different clades of Juniperus. Biogeographic results supported multiple long-distance dispersal events and niche variation that contributed to the modern range of Juniperus, while both phenotypic adaptation and ecological opportunity probably drove its distribution range. Our findings suggest that the current widespread distribution is likely the result of significant divergence driven by niche variation in which ecological opportunities from key innovation and phenotypic divergence.
Collapse
Affiliation(s)
- Kangjia Liu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Enze Li
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Xingyong Cui
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Yushuang Wang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Chao Xu
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Zhili Suo
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Wenpan Dong
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China.
| | - Zhixiang Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China.
| |
Collapse
|
2
|
Ferrer MM, Vásquez-Cruz M, Hernández-Hernández T, Good SV. Geographical and life-history traits associated with low and high species richness across angiosperm families. FRONTIERS IN PLANT SCIENCE 2023; 14:1276727. [PMID: 38107007 PMCID: PMC10722503 DOI: 10.3389/fpls.2023.1276727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 10/26/2023] [Indexed: 12/19/2023]
Abstract
Introduction The phenomenal expansion of angiosperms has prompted many investigations into the factors driving their diversification, but there remain significant gaps in our understanding of flowering plant species diversity. Methods Using the crown age of families from five studies, we used a maximum likelihood approach to classify families as having poor, predicted or high species richness (SR) using strict consensus criteria. Using these categories, we looked for associations between family SR and i) the presence of an inferred familial ancestral polyploidization event, ii) 23 life history and floral traits compiled from previously published datasets and papers, and iii) sexual system (dioecy) or genetically determined self-incompatibility (SI) mating system using an updated version of our own database and iv) geographic distribution using a new database describing the global distribution of plant species/families across realms and biomes and inferred range. Results We find that more than a third of angiosperm families (65%) had predicted SR, a large proportion (30.2%) were species poor, while few (4.8%) had high SR. Families with poor SR were less likely to have undergone an ancestral polyploidization event, exhibited deficits in diverse traits, and were more likely to have unknown breeding systems and to be found in only one or few biomes and realms, especially the Afrotropics or Australasia. On the other hand, families with high SR were more likely to have animal mediated pollination or dispersal, are enriched for epiphytes and taxa with an annual life history, and were more likely to harbour sporophytic SI systems. Mapping the global distribution of georeferenced taxa by their family DR, we find evidence of regions dominated by taxa from lineages with high vs low SR. Discussion These results are discussed within the context of the literature describing "depauperons" and the factors contributing to low and high biodiversity in angiosperm clades.
Collapse
Affiliation(s)
- Miriam Monserrat Ferrer
- Departamento de Manejo y Conservación de Recursos Naturales Tropicales, Universidad Autónoma de Yucatán, Mérida Yucatán, Mexico
| | | | | | - Sara V. Good
- Department of Biology, The University of Winnipeg, Winnipeg, MB, Canada
| |
Collapse
|
3
|
Ren CQ, Zhang DQ, Liu XY, Zhang JQ. Genomic data provide a robust phylogeny backbone for Rhodiola L. (Crassulaceae) and reveal extensive reticulate evolution during its rapid radiation. Mol Phylogenet Evol 2023:107863. [PMID: 37329933 DOI: 10.1016/j.ympev.2023.107863] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/19/2023]
Abstract
The Tibetan Plateau and adjacent mountain regions (TP; including the Tibetan Plateau, Himalaya, Hengduan Mountains and Mountains of Central Asia) harbor great biodiversity, some lineages on which may have undergone rapid radiations. However, only a few studies have investigated the evolutionary pattern of such diversification in depth using genomic data. In this study, we reconstructed a robust phylogeny backbone of Rhodiola, a lineage that may have undergone rapid radiation in the TP, using Genotyping-by-sequencing data, and conducted a series of gene flow and diversification analyses. The concatenation and coalescent-based methods yield similar tree topologies, and five well-supported clades were revealed. Potential gene flow and introgression events were detected, both between species from different major clades and closely related species, suggesting pervasive hybridization and introgression. An initial rapid and later slowdown of the diversification rate was revealed, indicating niche filling. Molecular dating and correlation analyses showed that the uplift of TP and global cooling in the mid-Miocene might have played an important role in promoting the rapid radiation of Rhodiola. Our work demonstrates that gene flow and introgression might be an important contributor to rapid radiation possibly by quickly reassembling old genetic variation into new combinations.
Collapse
Affiliation(s)
- Chun-Qian Ren
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China; Key Laboratory of Medicinal Plant Resource and Natural Pharmaceutical Chemistry of Ministry of Education, Shaanxi Normal University, Xi'an 710119, China
| | - Dan-Qing Zhang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China; Key Laboratory of Medicinal Plant Resource and Natural Pharmaceutical Chemistry of Ministry of Education, Shaanxi Normal University, Xi'an 710119, China
| | - Xiao-Ying Liu
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China; Key Laboratory of Medicinal Plant Resource and Natural Pharmaceutical Chemistry of Ministry of Education, Shaanxi Normal University, Xi'an 710119, China
| | - Jian-Qiang Zhang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China; Key Laboratory of Medicinal Plant Resource and Natural Pharmaceutical Chemistry of Ministry of Education, Shaanxi Normal University, Xi'an 710119, China.
| |
Collapse
|
4
|
Anderson B, Pannell J, Billiard S, Burgarella C, de Boer H, Dufay M, Helmstetter AJ, Méndez M, Otto SP, Roze D, Sauquet H, Schoen D, Schönenberger J, Vallejo-Marin M, Zenil-Ferguson R, Käfer J, Glémin S. Opposing effects of plant traits on diversification. iScience 2023; 26:106362. [PMID: 37034980 PMCID: PMC10074578 DOI: 10.1016/j.isci.2023.106362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Species diversity can vary dramatically across lineages due to differences in speciation and extinction rates. Here, we explore the effects of several plant traits on diversification, finding that most traits have opposing effects on diversification. For example, outcrossing may increase the efficacy of selection and adaptation but also decrease mate availability, two processes with contrasting effects on lineage persistence. Such opposing trait effects can manifest as differences in diversification rates that depend on ecological context, spatiotemporal scale, and associations with other traits. The complexity of pathways linking traits to diversification suggests that the mechanistic underpinnings behind their correlations may be difficult to interpret with any certainty, and context dependence means that the effects of specific traits on diversification are likely to differ across multiple lineages and timescales. This calls for taxonomically and context-controlled approaches to studies that correlate traits and diversification.
Collapse
|
5
|
Helmstetter AJ, Zenil-Ferguson R, Sauquet H, Otto SP, Méndez M, Vallejo-Marin M, Schönenberger J, Burgarella C, Anderson B, de Boer H, Glémin S, Käfer J. Trait-dependent diversification in angiosperms: Patterns, models and data. Ecol Lett 2023; 26:640-657. [PMID: 36829296 DOI: 10.1111/ele.14170] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 12/19/2022] [Accepted: 12/22/2022] [Indexed: 02/26/2023]
Abstract
Variation in species richness across the tree of life, accompanied by the incredible variety of ecological and morphological characteristics found in nature, has inspired many studies to link traits with species diversification. Angiosperms are a highly diverse group that has fundamentally shaped life on earth since the Cretaceous, and illustrate how species diversification affects ecosystem functioning. Numerous traits and processes have been linked to differences in species richness within this group, but we know little about their relative importance and how they interact. Here, we synthesised data from 152 studies that used state-dependent speciation and extinction (SSE) models on angiosperm clades. Intrinsic traits related to reproduction and morphology were often linked to diversification but a set of universal drivers did not emerge as traits did not have consistent effects across clades. Importantly, SSE model results were correlated to data set properties - trees that were larger, older or less well-sampled tended to yield trait-dependent outcomes. We compared these properties to recommendations for SSE model use and provide a set of best practices to follow when designing studies and reporting results. Finally, we argue that SSE model inferences should be considered in a larger context incorporating species' ecology, demography and genetics.
Collapse
Affiliation(s)
- Andrew J Helmstetter
- Fondation pour la recherche sur la biodiversité-CEntre de Synthèse et d'Analyse sur la Biodiversité, Montpellier, France
| | | | - Hervé Sauquet
- National Herbarium of New South Wales, Royal Botanic Gardens and Domain Trust, Sydney, New South Wales, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Sarah P Otto
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marcos Méndez
- Area of Biodiversity and Conservation, Universidad Rey Juan Carlos, Móstoles, Madrid, Spain
| | | | - Jürg Schönenberger
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | | | - Bruce Anderson
- Department of Botany and Zoology, University of Stellenbosch, Matieland, South Africa
| | - Hugo de Boer
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Sylvain Glémin
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
- CNRS, Ecosystèmes Biodiversité Evolution (Université de Rennes), Rennes, France
| | - Jos Käfer
- Université de Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive UMR 5558, Villeurbanne, France
- DIADE, Université de Montpellier, IRD, CIRAD, Montpellier, France
| |
Collapse
|
6
|
Brignone NF, Pozner R, Denham SS. Macroevolutionary trends and diversification dynamics in Atripliceae (Amaranthaceae s.l., Chenopodioideae): a first approach. ANNALS OF BOTANY 2022; 130:199-214. [PMID: 35737947 PMCID: PMC9445597 DOI: 10.1093/aob/mcac085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND AIMS Atripliceae evolved and diversified by dispersals and radiations across continents in both hemispheres, colonizing similar semi-arid, saline-alkaline environments throughout the world. Meanwhile, its species developed different life forms, photosynthetic pathways, mono- or dioecy, and different morphological features in flowers, fruiting bracteoles and seeds. In this study, we introduce a first approach to the macroevolutionary patterns and diversification dynamics of the Atripliceae to understand how time, traits, speciation, extinction and new habitats influenced the evolution of this lineage. METHODS We performed molecular phylogenetic analyses and clade age estimation of Atripliceae to apply time-, trait- and geographic-dependent diversification analyses and ancestral state reconstructions to explore diversification patterns within the tribe. KEY RESULTS Opposite diversification dynamics within the two major clades of Atripliceae, the Archiatriplex and Atriplex clades, could explain the unbalanced species richness between them; we found low mean speciation rates in the Archiatriplex clade and one shift to higher speciation rates placed in the branch of the Atriplex core. This acceleration in diversification seems to have started before the transition between C3 and C4 metabolism and before the arrival of Atriplex in the Americas, and matches the Mid-Miocene Climatic Optimum. Besides, the American species of Atriplex exhibit slightly higher net diversification rates than the Australian and Eurasian ones. While time seems not to be associated with diversification, traits such as life form, photosynthetic pathway and plant sex may have played roles as diversification drivers. CONCLUSIONS Traits more than time played a key role in Atripliceae diversification, and we could speculate that climate changes could have triggered speciation. The extreme arid or saline environments where Atripliceae species prevail may explain its particular evolutionary trends and trait correlations compared with other angiosperms and highlight the importance of conservation efforts needed to preserve them as genetic resources to deal with climatic changes.
Collapse
Affiliation(s)
| | - Raúl Pozner
- Instituto de Botánica Darwinion (Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Ciencias Exactas, Físicas y Naturales), Labardén, Casilla de Correo, San Isidro, Buenos Aires, Argentina
| | - Silvia S Denham
- Instituto de Botánica Darwinion (Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Ciencias Exactas, Físicas y Naturales), Labardén, Casilla de Correo, San Isidro, Buenos Aires, Argentina
- Laboratorio de Investigaciones en Biotecnología Sustentable (LIBioS), Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña, Bernal, Buenos Aires, Argentina
- Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
| |
Collapse
|
7
|
Cássia-Silva C, Freitas CG, Jardim L, Bacon CD, Collevatti RG. In situ radiation explains the frequency of dioecious palms on islands. ANNALS OF BOTANY 2021; 128:205-215. [PMID: 33949659 PMCID: PMC8324027 DOI: 10.1093/aob/mcab056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND AIMS Dioecy has evolved up to 5000 times in angiosperms, despite the potentially high intrinsic costs to unisexuality. Dioecy prevents inbreeding, which is especially relevant on isolated islands when gene pools are small. Dioecy is also associated with certain dispersal traits, such as fruit size and type. However, the influence of dioecy on other life history traits and island distribution remains poorly understood. Here, we test the effect of dioecy on palm (Arecaceae) speciation rates, fruit size and frequency on islands. METHODS We used phylogenetic comparative methods to estimate the ancestral state of the sexual system and its impact on speciation rates and fruit size. Frequency of sexual systems, effect of insularity on the probability of being dioecious, and phylogenetic clustering of island dioecious vs. mainland species were inferred. Lastly, we determined the interplay of insularity and sexual system on speciation rates. KEY RESULTS Palms repeatedly evolved different sexual systems (dioecy, monoecy and polygamy) from a hermaphrodite origin. Differences in speciation rates and fruit size among the different sexual systems were not identified. An effect of islands on the probability of the palms being dioecious was also not found. However, we found a high frequency and phylogenetic clustering of dioecious palms on islands, which were not correlated with higher speciation rates. CONCLUSIONS The high frequency and phylogenetic clustering may be the result of in situ radiation and suggest an 'island effect' for dioecious palms, which was not explained by differential speciation rates. This island effect also cannot be attributed to long-distance dispersal due to the lack of fruit size difference among sexual systems, and particularly because palm dispersal to islands is highly constrained by the interaction between the sizes of fruit and frugivores. Taken together, we suggest that trait flexibility in sexual system evolution and the in situ radiation of dioecious lineages are the underlying causes of the outstanding distribution of palms on islands.
Collapse
Affiliation(s)
- Cibele Cássia-Silva
- Laboratório de Genética & Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Cíntia G Freitas
- Pós-Graduação em Ecologia e Conservação, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Lucas Jardim
- Laboratório de Ecologia Teórica e Síntese, Departamento de Ecologia, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Christine D Bacon
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - Rosane G Collevatti
- Laboratório de Genética & Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| |
Collapse
|
8
|
Wang Y, Luo A, Lyu T, Dimitrov D, Xu X, Freckleton RP, Li Y, Su X, Li Y, Liu Y, Sandanov D, Li Q, Hao Z, Liu S, Wang Z. Global distribution and evolutionary transitions of angiosperm sexual systems. Ecol Lett 2021; 24:1835-1847. [PMID: 34121305 DOI: 10.1111/ele.13815] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/01/2021] [Accepted: 05/03/2021] [Indexed: 01/08/2023]
Abstract
Angiosperm sexual systems are fundamental to the evolution and distribution of plant diversity, yet spatiotemporal patterns in angiosperm sexual systems and their drivers remain poorly known. Using data on sexual systems and distributions of 68453 angiosperm species, we present the first global maps of sexual system frequencies and evaluate sexual system evolution during the Cenozoic. Frequencies of dioecy and monoecy increase with latitude, while hermaphrodites are more frequent in warm and arid regions. Transitions to dioecy from other states were higher than to hermaphroditism, but transitions away from dioecy increased since the Cenozoic, suggesting that dioecy is not an evolutionary end point. Transitions between hermaphroditism and dioecy increased, while transitions to monoecy decreased with paleo-temperature when paleo-temperature >0℃. Our study demonstrates the biogeography of angiosperm sexual systems from a macroecological perspective, and enhances our understanding of plant diversity patterns and their response to climate change.
Collapse
Affiliation(s)
- Yunyun Wang
- Faculty of Life Science and Technology, Central South University of Forestry and Technology and National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Changsha, China.,Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Ao Luo
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Tong Lyu
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Dimitar Dimitrov
- Department of Natural History, University Museum of Bergen, University of Bergen, Bergen, Norway
| | - Xiaoting Xu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Robert P Freckleton
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Yaoqi Li
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Xiangyan Su
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yichao Li
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yunpeng Liu
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Denis Sandanov
- Institute of General and Experimental Biology, Siberian Branch of Russian Academy of Science, Ulan-Ude, Russia
| | - Qingjun Li
- Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, Yunnan, China
| | - Zhanqing Hao
- Research Center for Ecology and Environmental Sciences, Xian, China
| | - Shuguang Liu
- Faculty of Life Science and Technology, Central South University of Forestry and Technology and National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Changsha, China
| | - Zhiheng Wang
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| |
Collapse
|
9
|
The rapid dissolution of dioecy by experimental evolution. Curr Biol 2021; 31:1277-1283.e5. [PMID: 33472050 DOI: 10.1016/j.cub.2020.12.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/10/2020] [Accepted: 12/18/2020] [Indexed: 11/20/2022]
Abstract
Evolutionary transitions from hermaphroditism to dioecy have been common in flowering plants,1,2 but recent analysis also points to frequent reversions from dioecy to hermaphroditism.2-4 Here, we use experimental evolution to expose a mechanism for such reversions, validating an explanation for the scattered phylogenetic distribution of dioecy. We removed males from dioecious populations of the wind-pollinated plant Mercurialis annua and allowed natural selection to act on the remaining females that occasionally produced male flowers; such "leaky" sex expression is common in both males and females of dioecious plants.5 Over the course of four generations, females evolved a 23-fold increase in average male flower production. This phenotypic masculinization of females coincided with the evolution of partial self-fertilization, high average seed set in the continued absence of males, and a capacity to sire progeny when males were re-introduced into their populations. Our study thus validates a mechanism for the rapid dissolution of dioecy and the evolution of functional hermaphroditism under conditions that may frequently occur during periods of low population density, repeated colonization, or range expansion.6,7 Our results illustrate the power of natural selection, acting in replicated experimental populations, to bring about transitions in the mating behavior of plants.
Collapse
|
10
|
Abstract
In flowering plants, transitions from bisexuality to unisexuality occur often, and have been considered irreversible. A new experimental evolution study demonstrates that this is unlikely to be true - 'leaky' sex expression can promote reversions to hermaphroditism when mates are scarce.
Collapse
Affiliation(s)
- Spencer C H Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willocks Street, Toronto, ON, Canada.
| |
Collapse
|
11
|
Muyle A, Martin H, Zemp N, Mollion M, Gallina S, Tavares R, Silva A, Bataillon T, Widmer A, Glémin S, Touzet P, Marais GAB. Dioecy Is Associated with High Genetic Diversity and Adaptation Rates in the Plant Genus Silene. Mol Biol Evol 2021; 38:805-818. [PMID: 32926156 PMCID: PMC7947750 DOI: 10.1093/molbev/msaa229] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
About 15,000 angiosperm species (∼6%) have separate sexes, a phenomenon known as dioecy. Why dioecious taxa are so rare is still an open question. Early work reported lower species richness in dioecious compared with nondioecious sister clades, raising the hypothesis that dioecy may be an evolutionary dead-end. This hypothesis has been recently challenged by macroevolutionary analyses that detected no or even positive effect of dioecy on diversification. However, the possible genetic consequences of dioecy at the population level, which could drive the long-term fate of dioecious lineages, have not been tested so far. Here, we used a population genomics approach in the Silene genus to look for possible effects of dioecy, especially for potential evidence of evolutionary handicaps of dioecy underlying the dead-end hypothesis. We collected individual-based RNA-seq data from several populations in 13 closely related species with different sexual systems: seven dioecious, three hermaphroditic, and three gynodioecious species. We show that dioecy is associated with increased genetic diversity, as well as higher selection efficacy both against deleterious mutations and for beneficial mutations. The results hold after controlling for phylogenetic inertia, differences in species census population sizes and geographic ranges. We conclude that dioecious Silene species neither show signs of increased mutational load nor genetic evidence for extinction risk. We discuss these observations in the light of the possible demographic differences between dioecious and self-compatible hermaphroditic species and how this could be related to alternatives to the dead-end hypothesis to explain the rarity of dioecy.
Collapse
Affiliation(s)
- Aline Muyle
- Laboratoire de Biométrie et Biologie Evolutive (UMR 5558), CNRS/Université Lyon 1, Villeurbanne, France
- Department of Ecology and Evolutionary Biology, UC Irvine, Irvine, CA
| | - Hélène Martin
- University of Lille, CNRS, UMR 8198—Evo-Eco-Paleo, F-59000 Lille, France
- Département de Biologie, Institut de Biologie Integrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Niklaus Zemp
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
- Genetic Diversity Centre (GDC), ETH Zurich, Zurich, Switzerland
| | - Maéva Mollion
- Bioinformatics Research Centre, Aarhus University, Aarhus C, Denmark
| | - Sophie Gallina
- University of Lille, CNRS, UMR 8198—Evo-Eco-Paleo, F-59000 Lille, France
| | - Raquel Tavares
- Laboratoire de Biométrie et Biologie Evolutive (UMR 5558), CNRS/Université Lyon 1, Villeurbanne, France
| | - Alexandre Silva
- Centro de Interpretação da Serra da Estrela (CISE), Seia, Portugal
| | - Thomas Bataillon
- Bioinformatics Research Centre, Aarhus University, Aarhus C, Denmark
| | - Alex Widmer
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Sylvain Glémin
- CNRS, ECOBIO [(Ecosystèmes, Biodiversité, Évolution)]—UMR 6553, University of Rennes, Rennes, France
- Department of Ecology and Genetics, Evolutionary Biology Center and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Pascal Touzet
- University of Lille, CNRS, UMR 8198—Evo-Eco-Paleo, F-59000 Lille, France
| | - Gabriel A B Marais
- Laboratoire de Biométrie et Biologie Evolutive (UMR 5558), CNRS/Université Lyon 1, Villeurbanne, France
| |
Collapse
|
12
|
Wang Y, Lyu T, Luo A, Li Y, Liu Y, Freckleton RP, Liu S, Wang Z. Spatial Patterns and Drivers of Angiosperm Sexual Systems in China Differ Between Woody and Herbaceous Species. FRONTIERS IN PLANT SCIENCE 2020; 11:1222. [PMID: 32849756 PMCID: PMC7432134 DOI: 10.3389/fpls.2020.01222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
Plant sexual systems play an important role in the evolution of angiosperm diversity. However, large-scale patterns in the frequencies of sexual systems (i.e. dioecy, monoecy, and hermaphroditism) and their drivers for species with different growth forms remain poorly known. Here, using a newly compiled database on the sexual systems and distributions of 19780 angiosperm species in China, we map the large-scale geographical patterns in frequencies of the sexual systems of woody and herbaceous species separately. We use these data to test the following two hypotheses: (1) the prevalence of sexual systems differs between woody and herbaceous assemblies because woody plants have taller canopies and are found in warm and humid climates; (2) the relative contributions of different drivers (specifically climate, evolutionary age, and mature plant height) to these patterns differ between woody and herbaceous species. We show that geographical patterns in proportions of different sexual systems (especially dioecy) differ between woody and herbaceous species. Geographical variations in sexual systems of woody species were influenced by climate, evolutionary age and plant height. In contrast, these have only weakly significant effects on the patterns of sexual systems of herbaceous species. We suggest that differences between species with woody and herbaceous growth forms in terms of biogeographic patterns of sexual systems, and their drivers, may reflect their differences in physiological and ecological adaptions, as well as the coevolution of sexual system with vegetative traits in response to environmental changes.
Collapse
Affiliation(s)
- Yunyun Wang
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, and College of Life Science and Technology, Central South University of Forest and Technology, Changsha, China
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Tong Lyu
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Ao Luo
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yaoqi Li
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yunpeng Liu
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Robert P. Freckleton
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Shuguang Liu
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, and College of Life Science and Technology, Central South University of Forest and Technology, Changsha, China
| | - Zhiheng Wang
- Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China
| |
Collapse
|
13
|
Shafir A, Azouri D, Goldberg EE, Mayrose I. Heterogeneity in the rate of molecular sequence evolution substantially impacts the accuracy of detecting shifts in diversification rates. Evolution 2020; 74:1620-1639. [PMID: 32510165 DOI: 10.1111/evo.14036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 05/17/2020] [Indexed: 12/01/2022]
Abstract
As species richness varies along the tree of life, there is a great interest in identifying factors that affect the rates by which lineages speciate or go extinct. To this end, theoretical biologists have developed a suite of phylogenetic comparative methods that aim to identify where shifts in diversification rates had occurred along a phylogeny and whether they are associated with some traits. Using these methods, numerous studies have predicted that speciation and extinction rates vary across the tree of life. In this study, we show that asymmetric rates of sequence evolution lead to systematic biases in the inferred phylogeny, which in turn lead to erroneous inferences regarding lineage diversification patterns. The results demonstrate that as the asymmetry in sequence evolution rates increases, so does the tendency to select more complicated models that include the possibility of diversification rate shifts. These results thus suggest that any inference regarding shifts in diversification pattern should be treated with great caution, at least until any biases regarding the molecular substitution rate have been ruled out.
Collapse
Affiliation(s)
- Anat Shafir
- School of Plant Sciences and Food security, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Dana Azouri
- School of Plant Sciences and Food security, Tel Aviv University, Ramat Aviv, 69978, Israel.,School of Molecular Cell Biology & Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | | | - Itay Mayrose
- School of Plant Sciences and Food security, Tel Aviv University, Ramat Aviv, 69978, Israel
| |
Collapse
|
14
|
Skeels A, Cardillo M. Reconstructing the Geography of Speciation from Contemporary Biodiversity Data. Am Nat 2019; 193:240-255. [DOI: 10.1086/701125] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
15
|
Santos Del Blanco L, Tudor E, Pannell JR. Low siring success of females with an acquired male function illustrates the legacy of sexual dimorphism in constraining the breakdown of dioecy. Ecol Lett 2019; 22:486-497. [PMID: 30618173 PMCID: PMC6850444 DOI: 10.1111/ele.13207] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/24/2018] [Accepted: 11/20/2018] [Indexed: 01/03/2023]
Abstract
Dioecy has often broken down in flowering plants, yielding functional hermaphroditism. We reasoned that evolutionary transitions from dioecy to functional hermaphroditism must overcome an inertia of sexual dimorphism, because modified males or females will express the opposite sexual function for which their phenotypes have been optimised. We tested this prediction by assessing the siring success of monoecious individuals of the plant Mercurialis annua with an acquired male function but that are phenotypically still female‐like. We found that pollen dispersed by female‐like monoecious individuals was ~ 1/3 poorer at siring outcrossed offspring than pollen from monoecious individuals with an alternative male‐like inflorescence. We conclude that whereas dioecy might evolve from functional hermaphroditism by conferring upon individuals certain benefits of sexual specialisation, reversion from a strategy of separate sexes to one of combined sexes must overcome constraints imposed by the advantages of sexual dimorphism. The breakdown of dioecy must therefore often be limited to situations in which outcrossing cannot be maintained and where selection favours a capacity for inbreeding by functional hermaphrodites.
Collapse
Affiliation(s)
- Luis Santos Del Blanco
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, 1015, Lausanne, Switzerland
| | - Eleri Tudor
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - John R Pannell
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, 1015, Lausanne, Switzerland
| |
Collapse
|
16
|
Zhang Q, Onstein RE, Little SA, Sauquet H. Estimating divergence times and ancestral breeding systems in Ficus and Moraceae. ANNALS OF BOTANY 2019; 123:191-204. [PMID: 30202847 PMCID: PMC6344110 DOI: 10.1093/aob/mcy159] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 08/06/2018] [Indexed: 05/30/2023]
Abstract
Background and Aims Although dioecy, which characterizes only 6 % of angiosperm species, has been considered an evolutionary dead end, recent studies have demonstrated that this is not necessarily the case. Moraceae (40 genera, 1100 spp., including Ficus, 750 spp.) are particularly diverse in breeding systems (including monoecy, gynodioecy, androdioecy and dioecy) and thus represent a model clade to study macroevolution of dioecy. Methods Ancestral breeding systems of Ficus and Moraceae were inferred. To do so, a new dated phylogenetic tree of Ficus and Moraceae was first reconstructed by combining a revised 12-fossil calibration set and a densely sampled molecular data set of eight markers and 320 species. Breeding system evolution was then reconstructed using both parsimony and model-based (maximum likelihood and Bayesian) approaches with this new time scale. Key Results The crown group ages of Ficus and Moraceae were estimated in the Eocene (40.6-55.9 Ma) and Late Cretaceous (73.2-84.7 Ma), respectively. Strong support was found for ancestral dioecy in Moraceae. Although the ancestral state of Ficus remained particularly sensitive to model selection, the results show that monoecy and gynodioecy evolved from dioecy in Moraceae, and suggest that gynodioecy probably evolved from monoecy in Ficus. Conclusions Dioecy was found not to be an evolutionary dead end in Moraceae. This study provides a new time scale for the phylogeny and a new framework of breeding system evolution in Ficus and Moraceae.
Collapse
Affiliation(s)
- Qian Zhang
- Laboratoire Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Renske E Onstein
- Laboratoire Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
- German Centre for Integrative Biodiversity Research (iDiv), Halle‐Jena‐Leipzig, Leipzig, Germany
| | - Stefan A Little
- Laboratoire Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Hervé Sauquet
- Laboratoire Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
- National Herbarium of New South Wales (NSW), Royal Botanic Gardens and Domain Trust, Sydney, Australia
| |
Collapse
|
17
|
Singhal S, Huang H, Grundler MR, Marchán-Rivadeneira MR, Holmes I, Title PO, Donnellan SC, Rabosky DL. Does Population Structure Predict the Rate of Speciation? A Comparative Test across Australia’s Most Diverse Vertebrate Radiation. Am Nat 2018; 192:432-447. [DOI: 10.1086/699515] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
18
|
Pennell MW, Mank JE, Peichel CL. Transitions in sex determination and sex chromosomes across vertebrate species. Mol Ecol 2018; 27:3950-3963. [PMID: 29451715 PMCID: PMC6095824 DOI: 10.1111/mec.14540] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 01/30/2018] [Accepted: 02/06/2018] [Indexed: 12/14/2022]
Abstract
Despite the prevalence of sexual reproduction across eukaryotes, there is a remarkable diversity of sex-determination mechanisms. The underlying causes of this diversity remain unclear, and it is unknown whether there are convergent trends in the directionality of turnover in sex-determination mechanisms. We used the recently assembled Tree of Sex database to assess patterns in the evolution of sex-determination systems in the remarkably diverse vertebrate clades of teleost fish, squamate reptiles and amphibians. Contrary to theoretical predictions, we find no evidence that the evolution of separate sexes is irreversible, as transitions from separate sexes to hermaphroditism occur at higher rates than the reverse in fish. We also find that transitions from environmental sex determination to genetic sex determination occur at higher rates than the reverse in both squamates and fish, suggesting that genetic sex determination is more stable. However, our data are not consistent with the hypothesis that heteromorphic sex chromosomes are an "evolutionary trap." Rather, we find similar transition rates between homomorphic and heteromorphic sex chromosomes in both fish and amphibians, and to environmental sex determination from heteromorphic vs. homomorphic sex chromosome systems in fish. Finally, we find that transitions between male and female heterogamety occur at similar rates in amphibians and squamates, while transitions to male heterogamety occur at higher rates in fish. Together, these results provide the most comprehensive view to date of the evolution of vertebrate sex determination in a phylogenetic context, providing new insight into long-standing questions about the evolution of sexual reproduction.
Collapse
Affiliation(s)
- Matthew W. Pennell
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Judith E. Mank
- Department of Genetics, Evolution and Environment, University College London, London, UK
- Department of Organismal Biology, Uppsala University, Sweden
| | | |
Collapse
|
19
|
Walas Ł, Mandryk W, Thomas PA, Tyrała-Wierucka Ż, Iszkuło G. Sexual systems in gymnosperms: A review. Basic Appl Ecol 2018. [DOI: 10.1016/j.baae.2018.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
20
|
Vamosi JC, Magallón S, Mayrose I, Otto SP, Sauquet H. Macroevolutionary Patterns of Flowering Plant Speciation and Extinction. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:685-706. [PMID: 29489399 DOI: 10.1146/annurev-arplant-042817-040348] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Species diversity is remarkably unevenly distributed among flowering plant lineages. Despite a growing toolbox of research methods, the reasons underlying this patchy pattern have continued to perplex plant biologists for the past two decades. In this review, we examine the present understanding of transitions in flowering plant evolution that have been proposed to influence speciation and extinction. In particular, ploidy changes, transitions between tropical and nontropical biomes, and shifts in floral form have received attention and have offered some surprises in terms of which factors influence speciation and extinction rates. Mating systems and dispersal characteristics once predominated as determining factors, yet recent evidence suggests that these changes are not as influential as previously thought or are important only when paired with range shifts. Although range extent is an important correlate of speciation, it also influences extinction and brings an applied focus to diversification research. Recent studies that find that past diversification can predict present-day extinction risk open an exciting avenue for future research to help guide conservation prioritization.
Collapse
Affiliation(s)
- Jana C Vamosi
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada;
| | - Susana Magallón
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México 04510, México
| | - Itay Mayrose
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Sarah P Otto
- Department of Zoology and the Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Hervé Sauquet
- Laboratoire Écologie, Systématique, Évolution, Université Paris-Sud, CNRS UMR 8079, 91405 Orsay, France
- National Herbarium of New South Wales (NSW), Royal Botanic Gardens and Domain Trust, Sydney, NSW 2000, Australia
| |
Collapse
|
21
|
Goldberg EE, Otto SP, Vamosi JC, Mayrose I, Sabath N, Ming R, Ashman TL. Macroevolutionary synthesis of flowering plant sexual systems. Evolution 2017; 71:898-912. [PMID: 28085192 DOI: 10.1111/evo.13181] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Indexed: 01/22/2023]
Abstract
Sexual system is a key determinant of genetic variation and reproductive success, affecting evolution within populations and within clades. Much research in plants has focused on evolutionary transitions away from the most common state of hermaphroditism and toward the rare state of dioecy (separate sexes). Rather than transitions predominantly toward greater sexual differentiation, however, evolution may proceed in the direction of lesser sexual differentiation. We analyzed the macroevolutionary dynamics of sexual system in angiosperm genera that contain both dioecious and nondioecious species. Our phylogenetic analyses encompass a total of 2145 species from 40 genera. Overall, we found little evidence that rates of sexual system transitions are greater in any direction. Counting the number of inferred state changes revealed a mild prevalence of transitions away from hermaphroditism and away from dioecy, toward states of intermediate sexual differentiation. We identify genera in which future studies of sexual system evolution might be especially productive, and we discuss how integrating genetic or population-level studies of sexual system could improve the power of phylogenetic comparative analyses. Our work adds to the evidence that different selective pressures and constraints act in different groups, helping maintain the variety of sexual systems observed among plants.
Collapse
Affiliation(s)
- Emma E Goldberg
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, Minnesota, 55108
| | - Sarah P Otto
- Department of Zoology, University of British Columbia, Vancouver, BC, V6J 3S7, Canada
| | - Jana C Vamosi
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Itay Mayrose
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv 69978, Israel
| | - Niv Sabath
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ray Ming
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.,Department of Plant Biology, University of Illinois, Urbana, Illinois, 61801
| | - Tia-Lynn Ashman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260
| |
Collapse
|
22
|
Käfer J, Marais GAB, Pannell JR. On the rarity of dioecy in flowering plants. Mol Ecol 2017; 26:1225-1241. [PMID: 28101895 DOI: 10.1111/mec.14020] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 12/27/2016] [Accepted: 12/28/2016] [Indexed: 01/21/2023]
Abstract
Dioecy, the coexistence of separate male and female individuals in a population, is a rare but phylogenetically widespread sexual system in flowering plants. While research has concentrated on why and how dioecy evolves from hermaphroditism, the question of why dioecy is rare, despite repeated transitions to it, has received much less attention. Previous phylogenetic and theoretical studies have suggested that dioecy might be an evolutionary dead end. However, recent research indicates that the phylogenetic support for this hypothesis is attributable to a methodological bias and that there is no evidence for reduced diversification in dioecious angiosperms. The relative rarity of dioecy thus remains a puzzle. Here, we review evidence for the hypothesis that dioecy might be rare not because it is an evolutionary dead end, but rather because it easily reverts to hermaphroditism. We review what is known about transitions between hermaphroditism and dioecy, and conclude that there is an important need to consider more widely the possibility of transitions away from dioecy, both from an empirical and a theoretical point of view, and by combining tools from molecular evolution and insights from ecology.
Collapse
Affiliation(s)
- Jos Käfer
- Laboratoire de Biométrie et Biologie Evolutive, CNRS, UMR 5558, Université Lyon 1, Bât. Grégor Mendel 43, bd du 11 novembre 1918, 69622, Villeurbanne cedex, France
| | - Gabriel A B Marais
- Laboratoire de Biométrie et Biologie Evolutive, CNRS, UMR 5558, Université Lyon 1, Bât. Grégor Mendel 43, bd du 11 novembre 1918, 69622, Villeurbanne cedex, France
| | - John R Pannell
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
| |
Collapse
|
23
|
Zhan SH, Drori M, Goldberg EE, Otto SP, Mayrose I. Phylogenetic evidence for cladogenetic polyploidization in land plants. AMERICAN JOURNAL OF BOTANY 2016; 103:1252-1258. [PMID: 27466054 DOI: 10.3732/ajb.1600108] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 07/12/2016] [Indexed: 06/06/2023]
Abstract
PREMISE OF THE STUDY Polyploidization is a common and recurring phenomenon in plants and is often thought to be a mechanism of "instant speciation". Whether polyploidization is associated with the formation of new species (cladogenesis) or simply occurs over time within a lineage (anagenesis), however, has never been assessed systematically. METHODS We tested this hypothesis using phylogenetic and karyotypic information from 235 plant genera (mostly angiosperms). We first constructed a large database of combined sequence and chromosome number data sets using an automated procedure. We then applied likelihood models (ClaSSE) that estimate the degree of synchronization between polyploidization and speciation events in maximum likelihood and Bayesian frameworks. KEY RESULTS Our maximum likelihood analysis indicated that 35 genera supported a model that includes cladogenetic transitions over a model with only anagenetic transitions, whereas three genera supported a model that incorporates anagenetic transitions over one with only cladogenetic transitions. Furthermore, the Bayesian analysis supported a preponderance of cladogenetic change in four genera but did not support a preponderance of anagenetic change in any genus. CONCLUSIONS Overall, these phylogenetic analyses provide the first broad confirmation that polyploidization is temporally associated with speciation events, suggesting that it is indeed a major speciation mechanism in plants, at least in some genera.
Collapse
Affiliation(s)
- Shing H Zhan
- Department of Zoology, 4200-6270 University Boulevard, University of British Columbia, Vancouver, British Columbia V6T 1Z4 Canada
| | - Michal Drori
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, P. O. Box 39040, Tel Aviv 69978, Israel
| | - Emma E Goldberg
- Department of Ecology, Evolution, & Behavior, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Avenue, St. Paul, Minnesota 55108 USA
| | - Sarah P Otto
- Department of Zoology, 4200-6270 University Boulevard, University of British Columbia, Vancouver, British Columbia V6T 1Z4 Canada
| | - Itay Mayrose
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, P. O. Box 39040, Tel Aviv 69978, Israel
| |
Collapse
|