1
|
Lyman RA, Edwards CE. Revisiting the comparative phylogeography of unglaciated eastern North America: 15 years of patterns and progress. Ecol Evol 2022; 12:e8827. [PMID: 35475178 PMCID: PMC9019306 DOI: 10.1002/ece3.8827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 11/28/2022] Open
Abstract
In a landmark comparative phylogeographic study, “Comparative phylogeography of unglaciated eastern North America,” Soltis et al. (Molecular Ecology, 2006, 15, 4261) identified geographic discontinuities in genetic variation shared across taxa occupying unglaciated eastern North America and proposed several common biogeographical discontinuities related to past climate fluctuations and geographic barriers. Since 2006, researchers have published many phylogeographical studies and achieved many advances in genotyping and analytical techniques; however, it is unknown how this work has changed our understanding of the factors shaping the phylogeography of eastern North American taxa. We analyzed 184 phylogeographical studies of eastern North American taxa published between 2007 and 2019 to evaluate: (1) the taxonomic focus of studies and whether a previously detected taxonomic bias towards studies focused on vertebrates has changed over time, (2) the extent to which studies have adopted genotyping technologies that improve the resolution of genetic groups (i.e., NGS DNA sequencing) and analytical approaches that facilitate hypothesis‐testing (i.e., divergence time estimation and niche modeling), and (3) whether new studies support the hypothesized biogeographic discontinuities proposed by Soltis et al. (Molecular Ecology, 2006, 15, 4261) or instead support new, previously undetected discontinuities. We observed little change in taxonomic focus over time, with studies still biased toward vertebrates. Although many technological and analytical advances became available during the period, uptake was slow and they were employed in only a small proportion of studies. We found variable support for previously identified discontinuities and identified one new recurrent discontinuity. However, the limited resolution and taxonomic breadth of many studies hindered our ability to clarify the most important climatological or geographical factors affecting taxa in the region. Broadening the taxonomic focus to include more non‐vertebrate taxa, employing technologies that improve genetic resolution, and using analytical approaches that improve hypothesis testing are necessary to strengthen our inference of the forces shaping the phylogeography of eastern North America.
Collapse
Affiliation(s)
- Rachel Ann Lyman
- Ecology, Evolution, and Population Biology Program Washington University in St. Louis St. Louis Missouri USA
- Center for Conservation and Sustainable Development Missouri Botanical Garden St. Louis Missouri USA
| | - Christine E. Edwards
- Center for Conservation and Sustainable Development Missouri Botanical Garden St. Louis Missouri USA
| |
Collapse
|
2
|
Mayer GC, Lazell J. The identity of the introduced green anole (Reptilia: Squamata) of Hawaii and other Pacific islands. P BIOL SOC WASH 2021. [DOI: 10.2988/0006-324x-134.1.294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Gregory C. Mayer
- (GCM) Department of Biological Sciences, University of Wisconsin-Parkside, Kenosha, WI, 53405, USA, e-mail:
| | - James Lazell
- (JL) The Conservation Agency, 6 Swinburne Street, Jamestown, RI, 02835, USA
| |
Collapse
|
3
|
Phylogeography of the Rough Greensnake, Opheodrys aestivus (Squamata: Colubridae), Using Multilocus Sanger Sequence and Genomic ddRADseq Data. J HERPETOL 2021. [DOI: 10.1670/20-040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
4
|
Bourgeois Y, Ruggiero RP, Hariyani I, Boissinot S. Disentangling the determinants of transposable elements dynamics in vertebrate genomes using empirical evidences and simulations. PLoS Genet 2020; 16:e1009082. [PMID: 33017388 PMCID: PMC7561263 DOI: 10.1371/journal.pgen.1009082] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 10/15/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022] Open
Abstract
The interactions between transposable elements (TEs) and their hosts constitute one of the most profound co-evolutionary processes found in nature. The population dynamics of TEs depends on factors specific to each TE families, such as the rate of transposition and insertional preference, the demographic history of the host and the genomic landscape. How these factors interact has yet to be investigated holistically. Here we are addressing this question in the green anole (Anolis carolinensis) whose genome contains an extraordinary diversity of TEs (including non-LTR retrotransposons, SINEs, LTR-retrotransposons and DNA transposons). We observed a positive correlation between recombination rate and frequency of TEs and densities for LINEs, SINEs and DNA transposons. For these elements, there was a clear impact of demography on TE frequency and abundance, with a loss of polymorphic elements and skewed frequency spectra in recently expanded populations. On the other hand, some LTR-retrotransposons displayed patterns consistent with a very recent phase of intense amplification. To determine how demography, genomic features and intrinsic properties of TEs interact we ran simulations using SLiM3. We determined that i) short TE insertions are not strongly counter-selected, but long ones are, ii) neutral demographic processes, linked selection and preferential insertion may explain positive correlations between average TE frequency and recombination, iii) TE insertions are unlikely to have been massively recruited in recent adaptation. We demonstrate that deterministic and stochastic processes have different effects on categories of TEs and that a combination of empirical analyses and simulations can disentangle these mechanisms.
Collapse
Affiliation(s)
- Yann Bourgeois
- School of Biological Sciences, University of Portsmouth, Portsmouth, United Kingdom
- New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
- * E-mail: (YB); (SB)
| | - Robert P. Ruggiero
- New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
- Department of Biology, Southeast Missouri State University, Cape Girardeau, MO, United States of America
| | - Imtiyaz Hariyani
- New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Stéphane Boissinot
- New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
- * E-mail: (YB); (SB)
| |
Collapse
|
5
|
Ramírez-Reyes T, Blair C, Flores-Villela O, Piñero D, Lathrop A, Murphy R. Phylogenomics and molecular species delimitation reveals great cryptic diversity of leaf-toed geckos (Phyllodactylidae: Phyllodactylus), ancient origins, and diversification in Mexico. Mol Phylogenet Evol 2020; 150:106880. [PMID: 32512192 DOI: 10.1016/j.ympev.2020.106880] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/25/2020] [Accepted: 06/01/2020] [Indexed: 10/24/2022]
Abstract
We utilize the efficient GBS technique to obtain thousands of nuclear loci and SNPs to reconstruct the evolutionary history of Mexican leaf-toed geckos (Phyllodactylus). Through the incorporation of unprecedented sampling for this group of geckos, in combination with genomic data analysis, we generate mostly consistent phylogenetic hypotheses using two approaches: supermatrix and coalescent-based inference. All topologies depict three, mutually exclusive major clades. Clade I comprises P. bordai and all species closer to P. bordai than to any other Phyllodactylus. Clade II comprises P. nocticolus and all species closer to P. nocticolus than to any other Phyllodactylus. Clade III comprises P. tuberculosus and all species closer to P. tuberculosus than to any other Phyllodactylus. Analyses estimate the age for the most recent common ancestor of Phyllodactylus in the Eocene (~43 mya), and the ancestors of each major clade date to the Eocene-Oligocene transition (32-36 mya). This group includes one late-Eocene lineage (P. bordai), Oligocene lineages (P. paucituberculatus, P. delcampi), but also topological patterns that indicate a recent radiation occurred during the Pleistocene on islands in the Gulf of California. The wide spatial and temporal scale indicates a complex and unique biogeographic history for each major clade. The 33 species delimited by BPP and stepping-stone BFD*coalescent based genomic approaches reflect this history. This diversity delimited for Mexican leaf-toed geckos demonstrates a vast underestimation in the number of species based on morphological data alone.
Collapse
Affiliation(s)
- Tonatiuh Ramírez-Reyes
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, 04510 Ciudad de México, Mexico; Museo de Zoología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior de CU, Ciudad Universitaria, 04510 Ciudad de México, Mexico; Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70-275, 04510 Ciudad de México, Mexico.
| | - Christopher Blair
- Department of Biological Sciences, New York City College of Technology, The City University of New York, 285 Jay Street, Brooklyn, NY 11201, USA; Biology PhD Program, CUNY Graduate Center, 365 5th Ave., New York, NY 10016, USA
| | - Oscar Flores-Villela
- Museo de Zoología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior de CU, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Daniel Piñero
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70-275, 04510 Ciudad de México, Mexico
| | - Amy Lathrop
- Royal Ontario Museum, Centre for Biodiversity and Conservation Biology, Toronto, Ontario, Canada
| | - Robert Murphy
- Royal Ontario Museum, Centre for Biodiversity and Conservation Biology, Toronto, Ontario, Canada; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Kunming, China
| |
Collapse
|
6
|
Bourgeois Y, Boissinot S. Selection at behavioural, developmental and metabolic genes is associated with the northward expansion of a successful tropical colonizer. Mol Ecol 2019; 28:3523-3543. [PMID: 31233650 DOI: 10.1111/mec.15162] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/28/2019] [Indexed: 02/06/2023]
Abstract
What makes a species able to colonize novel environments? This question is key to understand the dynamics of adaptive radiations and ecological niche shifts, but the mechanisms that underlie expansion into novel habitats remain poorly understood at a genomic scale. Lizards from the genus Anolis are typically tropical, and the green anole (Anolis carolinensis) constitutes an exception since it expanded into temperate North America from subtropical Florida. Thus, we used the green anole as a model to investigate signatures of selection associated with colonization of a new environment, namely temperate North America. To this end, we analysed 29 whole-genome sequences, covering the entire native range of the species. We used a combination of recent methods to quantify both positive and balancing selection in northern populations, including FST outlier methods, machine learning and ancestral recombination graphs. We naively scanned for genes of interest and assessed the overlap between multiple tests. Strikingly, we identified many genes involved in behaviour, suggesting that the recent successful colonization of northern environments may have been linked to behavioural shifts as well as physiological adaptation. Using a candidate genes strategy, we determined that genes involved in response to cold or behaviour displayed more frequently signals of selection, while controlling for local recombination rate, gene clustering and gene length. In addition, we found signatures of balancing selection at immune genes in all investigated genetic groups, but also at genes involved in neuronal and anatomical development.
Collapse
Affiliation(s)
- Yann Bourgeois
- New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | | |
Collapse
|
7
|
Bourgeois Y, Ruggiero RP, Manthey JD, Boissinot S. Recent Secondary Contacts, Linked Selection, and Variable Recombination Rates Shape Genomic Diversity in the Model Species Anolis carolinensis. Genome Biol Evol 2019; 11:2009-2022. [PMID: 31134281 PMCID: PMC6681179 DOI: 10.1093/gbe/evz110] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2019] [Indexed: 12/14/2022] Open
Abstract
Gaining a better understanding on how selection and neutral processes affect genomic diversity is essential to gain better insights into the mechanisms driving adaptation and speciation. However, the evolutionary processes affecting variation at a genomic scale have not been investigated in most vertebrate lineages. Here, we present the first population genomics survey using whole genome resequencing in the green anole (Anolis carolinensis). Anoles have been intensively studied to understand mechanisms underlying adaptation and speciation. The green anole in particular is an important model to study genome evolution. We quantified how demography, recombination, and selection have led to the current genetic diversity of the green anole by using whole-genome resequencing of five genetic clusters covering the entire species range. The differentiation of green anole's populations is consistent with a northward expansion from South Florida followed by genetic isolation and subsequent gene flow among adjacent genetic clusters. Dispersal out-of-Florida was accompanied by a drastic population bottleneck followed by a rapid population expansion. This event was accompanied by male-biased dispersal and/or selective sweeps on the X chromosome. We show that the interaction between linked selection and recombination is the main contributor to the genomic landscape of differentiation in the anole genome.
Collapse
Affiliation(s)
| | | | - Joseph D Manthey
- New York University Abu Dhabi, United Arab Emirates
- Department of Biological Sciences, Texas Tech University
| | | |
Collapse
|
8
|
Wegener JE, Pita‐Aquino JN, Atutubo J, Moreno A, Kolbe JJ. Hybridization and rapid differentiation after secondary contact between the native green anole ( Anolis carolinensis) and the introduced green anole ( Anolis porcatus). Ecol Evol 2019; 9:4138-4148. [PMID: 31015994 PMCID: PMC6468060 DOI: 10.1002/ece3.5042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/06/2019] [Accepted: 02/12/2019] [Indexed: 11/24/2022] Open
Abstract
In allopatric species, reproductive isolation evolves through the accumulation of genetic incompatibilities. The degree of divergence required for complete reproductive isolation is highly variable across taxa, which makes the outcome of secondary contact between allopatric species unpredictable. Since before the Pliocene, two species of Anolis lizards, Anolis carolinensis and Anolis porcatus, have been allopatric, yet this period of independent evolution has not led to substantial species-specific morphological differentiation, and therefore, they might not be reproductively isolated. In this study, we determined the genetic consequences of localized, secondary contact between the native green anole, A. carolinensis, and the introduced Cuban green anole, A. porcatus, in South Miami. Using 18 microsatellite markers, we found that the South Miami population formed a genetic cluster distinct from both parental species. Mitochondrial DNA revealed maternal A. porcatus ancestry for 35% of the individuals sampled from this population, indicating a high degree of cytonuclear discordance. Thus, hybridization with A. porcatus, not just population structure within A. carolinensis, may be responsible for the genetic distinctiveness of this population. Using tree-based maximum-likelihood analysis, we found support for a more recent, secondary introduction of A. porcatus to Florida. Evidence that ~33% of the nuclear DNA resulted from a secondary introduction supports the hybrid origin of the green anole population in South Miami. We used multiple lines of evidence and multiple genetic markers to reconstruct otherwise cryptic patterns of species introduction and hybridization. Genetic evidence for a lack of reproductive isolation, as well as morphological similarities between the two species, supports revising the taxonomy of A. carolinensis to include A. porcatus from western Cuba. Future studies should target the current geographic extent of introgression originating from the past injection of genetic material from Cuban green anoles and determine the consequences for the evolutionary trajectory of green anole populations in southern Florida.
Collapse
Affiliation(s)
- Johanna E. Wegener
- Department of Biological SciencesUniversity of Rhode IslandKingstonRhode Island
| | | | - Jessica Atutubo
- Department of Biological SciencesUniversity of Rhode IslandKingstonRhode Island
| | - Adam Moreno
- Department of Ecology and Evolutionary BiologyBrown UniversityProvidenceRhode Island
- Present address:
College of Veterinary MedicineOhio State UniversityColumbusOhio
| | - Jason J. Kolbe
- Department of Biological SciencesUniversity of Rhode IslandKingstonRhode Island
| |
Collapse
|
9
|
Tollis M, Hutchins ED, Stapley J, Rupp SM, Eckalbar WL, Maayan I, Lasku E, Infante CR, Dennis SR, Robertson JA, May CM, Crusoe MR, Bermingham E, DeNardo DF, Hsieh STT, Kulathinal RJ, McMillan WO, Menke DB, Pratt SC, Rawls JA, Sanjur O, Wilson-Rawls J, Wilson Sayres MA, Fisher RE, Kusumi K. Comparative Genomics Reveals Accelerated Evolution in Conserved Pathways during the Diversification of Anole Lizards. Genome Biol Evol 2018; 10:489-506. [PMID: 29360978 PMCID: PMC5798147 DOI: 10.1093/gbe/evy013] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2018] [Indexed: 11/21/2022] Open
Abstract
Squamates include all lizards and snakes, and display some of the most diverse and extreme morphological adaptations among vertebrates. However, compared with birds and mammals, relatively few resources exist for comparative genomic analyses of squamates, hampering efforts to understand the molecular bases of phenotypic diversification in such a speciose clade. In particular, the ∼400 species of anole lizard represent an extensive squamate radiation. Here, we sequence and assemble the draft genomes of three anole species-Anolis frenatus, Anolis auratus, and Anolis apletophallus-for comparison with the available reference genome of Anolis carolinensis. Comparative analyses reveal a rapid background rate of molecular evolution consistent with a model of punctuated equilibrium, and strong purifying selection on functional genomic elements in anoles. We find evidence for accelerated evolution in genes involved in behavior, sensory perception, and reproduction, as well as in genes regulating limb bud development and hindlimb specification. Morphometric analyses of anole fore and hindlimbs corroborated these findings. We detect signatures of positive selection across several genes related to the development and regulation of the forebrain, hormones, and the iguanian lizard dewlap, suggesting molecular changes underlying behavioral adaptations known to reinforce species boundaries were a key component in the diversification of anole lizards.
Collapse
Affiliation(s)
- Marc Tollis
- School of Life Sciences, Arizona State University
- Virginia G. Piper Center for Personalized Diagnostics, The Biodesign Institute at Arizona State University
| | - Elizabeth D Hutchins
- School of Life Sciences, Arizona State University
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, Arizona
| | - Jessica Stapley
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
| | - Shawn M Rupp
- School of Life Sciences, Arizona State University
| | | | - Inbar Maayan
- School of Life Sciences, Arizona State University
| | - Eris Lasku
- School of Life Sciences, Arizona State University
| | - Carlos R Infante
- Department of Genetics, University of Georgia
- Department of Molecular and Cellular Biology, University of Arizona
| | - Stuart R Dennis
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
| | | | | | | | - Eldredge Bermingham
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
- Patricia and Phillip Frost Museum of Science, Miami, Florida
| | | | | | | | | | | | | | | | - Oris Sanjur
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
| | | | - Melissa A Wilson Sayres
- School of Life Sciences, Arizona State University
- The Center for Evolution and Medicine, Arizona State University
| | - Rebecca E Fisher
- School of Life Sciences, Arizona State University
- Department of Basic Medical Sciences, University of Arizona College of Medicine–Phoenix
| | - Kenro Kusumi
- School of Life Sciences, Arizona State University
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, Arizona
- Department of Basic Medical Sciences, University of Arizona College of Medicine–Phoenix
| |
Collapse
|
10
|
Michaelides SN, Goodman RM, Crombie RI, Kolbe JJ. Independent introductions and sequential founder events shape genetic differentiation and diversity of the invasive green anole (Anolis carolinensis) on Pacific Islands. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12704] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
| | - Rachel M. Goodman
- Department of Biology; Hampden-Sydney College; Hampden Sydney VA USA
| | | | - Jason J. Kolbe
- Department of Biological Sciences; University of Rhode Island; Kingston RI USA
| |
Collapse
|
11
|
Wanke S, Granados Mendoza C, Müller S, Paizanni Guillén A, Neinhuis C, Lemmon AR, Lemmon EM, Samain MS. Recalcitrant deep and shallow nodes in Aristolochia (Aristolochiaceae) illuminated using anchored hybrid enrichment. Mol Phylogenet Evol 2017; 117:111-123. [DOI: 10.1016/j.ympev.2017.05.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 01/05/2023]
|
12
|
Ruggiero RP, Bourgeois Y, Boissinot S. LINE Insertion Polymorphisms are Abundant but at Low Frequencies across Populations of Anolis carolinensis. Front Genet 2017; 8:44. [PMID: 28450881 PMCID: PMC5389967 DOI: 10.3389/fgene.2017.00044] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/29/2017] [Indexed: 12/30/2022] Open
Abstract
Vertebrate genomes differ considerably in size and structure. Among the features that show the most variation is the abundance of Long Interspersed Nuclear Elements (LINEs). Mammalian genomes contain 100,000s LINEs that belong to a single clade, L1, and in most species a single family is usually active at a time. In contrast, non-mammalian vertebrates (fish, amphibians and reptiles) contain multiple active families, belonging to several clades, but each of them is represented by a small number of recently inserted copies. It is unclear why vertebrate genomes harbor such drastic differences in LINE composition. To address this issue, we conducted whole genome resequencing to investigate the population genomics of LINEs across 13 genomes of the lizard Anolis carolinensis sampled from two geographically and genetically distinct populations in the Eastern Florida and the Gulf Atlantic regions of the United States. We used the Mobile Element Locator Tool to identify and genotype polymorphic insertions from five major clades of LINEs (CR1, L1, L2, RTE and R4) and the 41 subfamilies that constitute them. Across these groups we found large variation in the frequency of polymorphic insertions and the observed length distributions of these insertions, suggesting these groups vary in their activity and how frequently they successfully generate full-length, potentially active copies. Though we found an abundance of polymorphic insertions (over 45,000) most of these were observed at low frequencies and typically appeared as singletons. Site frequency spectra for most LINEs showed a significant shift toward low frequency alleles compared to the spectra observed for total genomic single nucleotide polymorphisms. Using Tajima's D, FST and the mean number of pairwise differences in LINE insertion polymorphisms, we found evidence that negative selection is acting on LINE families in a length-dependent manner, its effects being stronger in the larger Eastern Florida population. Our results suggest that a large effective population size and negative selection limit the expansion of polymorphic LINE insertions across these populations and that the probability of LINE polymorphisms reaching fixation is extremely low.
Collapse
|
13
|
Manthey JD, Tollis M, Lemmon AR, Moriarty Lemmon E, Boissinot S. Diversification in wild populations of the model organism Anolis carolinensis: A genome-wide phylogeographic investigation. Ecol Evol 2016; 6:8115-8125. [PMID: 27891220 PMCID: PMC5108263 DOI: 10.1002/ece3.2547] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/14/2016] [Accepted: 09/19/2016] [Indexed: 01/14/2023] Open
Abstract
The green anole (Anolis carolinensis) is a lizard widespread throughout the southeastern United States and is a model organism for the study of reproductive behavior, physiology, neural biology, and genomics. Previous phylogeographic studies of A. carolinensis using mitochondrial DNA and small numbers of nuclear loci identified conflicting and poorly supported relationships among geographically structured clades; these inconsistencies preclude confident use of A. carolinensis evolutionary history in association with morphological, physiological, or reproductive biology studies among sampling localities and necessitate increased effort to resolve evolutionary relationships among natural populations. Here, we used anchored hybrid enrichment of hundreds of genetic markers across the genome of A. carolinensis and identified five strongly supported phylogeographic groups. Using multiple analyses, we produced a fully resolved species tree, investigated relative support for each lineage across all gene trees, and identified mito‐nuclear discordance when comparing our results to previous studies. We found fixed differences in only one clade—southern Florida restricted to the Everglades region—while most polymorphisms were shared between lineages. The southern Florida group likely diverged from other populations during the Pliocene, with all other diversification during the Pleistocene. Multiple lines of support, including phylogenetic relationships, a latitudinal gradient in genetic diversity, and relatively more stable long‐term population sizes in southern phylogeographic groups, indicate that diversification in A. carolinensis occurred northward from southern Florida.
Collapse
Affiliation(s)
| | - Marc Tollis
- Biodesign Institute Arizona State University Tempe AZ USA
| | - Alan R Lemmon
- Department of Scientific Computing Florida State University Tallahassee FL USA
| | | | | |
Collapse
|