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Scherrer R, Donihue CM, Reynolds RG, Losos JB, Geneva AJ. Dewlap colour variation in Anolis sagrei is maintained among habitats within islands of the West Indies. J Evol Biol 2022; 35:680-692. [PMID: 35535762 PMCID: PMC9321103 DOI: 10.1111/jeb.14002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 11/30/2022]
Abstract
Animal signals evolve in an ecological context. Locally adapting animal sexual signals can be especially important for initiating or reinforcing reproductive isolation during the early stages of speciation. Previous studies have demonstrated that dewlap colour in Anolis lizards can be highly variable between populations in relation to both biotic and abiotic adaptive drivers at relatively large geographical scales. Here, we investigated differentiation of dewlap coloration among habitat types at a small spatial scale, within multiple islands of the West Indies, to test the hypothesis that similar local adaptive processes occur over smaller spatial scales. We explored variation in dewlap coloration in the most widespread species of anole, Anolis sagrei, across three characteristic habitats spanning the Bahamas and the Cayman Islands, namely beach scrub, primary coppice forest and mangrove forest. Using reflectance spectrometry paired with supervised machine learning, we found significant differences in spectral properties of the dewlap between habitats within small islands, sometimes over very short distances. Passive divergence in dewlap phenotype associated with isolation-by-distance did not seem to explain our results. On the other hand, these habitat-specific dewlap differences varied in magnitude and direction across islands, and thus, our primary test for adaptation-parallel responses across islands-was not supported. We suggest that neutral processes or selection could be involved in several ways, including sexual selection. Our results shed new light on the scale at which signal colour polymorphism can be maintained in the presence of gene flow, and the relative role of local adaptation and other processes in driving these patterns of dewlap colour variation across islands.
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Affiliation(s)
- Raphaël Scherrer
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Colin M Donihue
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Robert Graham Reynolds
- Department of Biology, University of North Carolina Asheville, Asheville, North Carolina, USA
| | - Jonathan B Losos
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Anthony J Geneva
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
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2
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de Mello PLH, Hime PM, Glor RE. Transcriptomic Analysis of Skin Color in Anole Lizards. Genome Biol Evol 2021; 13:evab110. [PMID: 33988681 PMCID: PMC8290120 DOI: 10.1093/gbe/evab110] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2021] [Indexed: 01/23/2023] Open
Abstract
Color and color pattern are critical for animal camouflage, reproduction, and defense. Few studies, however, have attempted to identify candidate genes for color and color pattern in squamate reptiles, a colorful group with over 10,000 species. We used comparative transcriptomic analyses between white, orange, and yellow skin in a color-polymorphic species of anole lizard to 1) identify candidate color and color-pattern genes in squamates and 2) assess if squamates share an underlying genetic basis for color and color pattern variation with other vertebrates. Squamates have three types of chromatophores that determine color pattern: guanine-filled iridophores, carotenoid- or pteridine-filled xanthophores/erythrophores, and melanin-filled melanophores. We identified 13 best candidate squamate color and color-pattern genes shared with other vertebrates: six genes linked to pigment synthesis pathways, and seven genes linked to chromatophore development and maintenance. In comparisons of expression profiles between pigment-rich and white skin, pigment-rich skin upregulated the pteridine pathway as well as xanthophore/erythrophore development and maintenance genes; in comparisons between orange and yellow skin, orange skin upregulated the pteridine and carotenoid pathways as well as melanophore maintenance genes. Our results corroborate the predictions that squamates can produce similar colors using distinct color-reflecting molecules, and that both color and color-pattern genes are likely conserved across vertebrates. Furthermore, this study provides a concise list of candidate genes for future functional verification, representing a first step in determining the genetic basis of color and color pattern in anoles.
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Affiliation(s)
- Pietro Longo Hollanda de Mello
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, KS, USA
| | - Paul M Hime
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, KS, USA
| | - Richard E Glor
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, KS, USA
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Prates I, D'Angiolella AB, Rodrigues MT, Melo-Sampaio PR, de Queiroz K, Bell RC. Evolutionary drivers of sexual signal variation in Amazon Slender Anoles. Evolution 2021; 75:1361-1376. [PMID: 33860933 DOI: 10.1111/evo.14230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 03/19/2021] [Accepted: 03/25/2021] [Indexed: 01/29/2023]
Abstract
Phenotypic variation among populations, as seen in the signaling traits of many species, provides an opportunity to test whether similar factors generate repeated phenotypic patterns in different parts of a species' range. We investigated whether genetic divergence, abiotic gradients, and sympatry with closely related species explain variation in the dewlap colors of Amazon Slender Anoles, Anolis fuscoauratus. To this aim, we characterized dewlap diversity in the field with respect to population genetic structure and evolutionary relationships, assessed whether dewlap phenotypes are associated with climate or landscape variables, and tested for nonrandom associations in the distributions of A. fuscoauratus phenotypes and sympatric Anolis species. We found that dewlap colors vary among but not within sites in A. fuscoauratus. Regional genetic clusters included multiple phenotypes, while populations with similar dewlaps were often distantly related. Phenotypes did not segregate in environmental space, providing no support for optimized signal transmission at a local scale. Instead, we found a negative association between certain phenotypes and sympatric Anolis species with similar dewlap color attributes, suggesting that interactions with closely related species promoted dewlap divergence among A. fuscoauratus populations. Amazon Slender Anoles emerge as a promising system to address questions about parallel trait evolution and the contribution of signaling traits to speciation.
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Affiliation(s)
- Ivan Prates
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, 20560.,Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, Michigan, 48109
| | | | - Miguel T Rodrigues
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Paulo R Melo-Sampaio
- Departamento de Vertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kevin de Queiroz
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, 20560
| | - Rayna C Bell
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, 20560.,Herpetology Department, California Academy of Sciences, San Francisco, California, 94118
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Stuart‐Fox D, Aulsebrook A, Rankin KJ, Dong CM, McLean CA. Convergence and divergence in lizard colour polymorphisms. Biol Rev Camb Philos Soc 2020; 96:289-309. [DOI: 10.1111/brv.12656] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Devi Stuart‐Fox
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
| | - Anne Aulsebrook
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
| | - Katrina J. Rankin
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
| | - Caroline M. Dong
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
- Sciences Department Museums Victoria 11 Nicholson Street Carlton Gardens VIC 3053 Australia
| | - Claire A. McLean
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
- Sciences Department Museums Victoria 11 Nicholson Street Carlton Gardens VIC 3053 Australia
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Myers TC, de Mello PLH, Glor RE. A morphometric assessment of species boundaries in a widespread anole lizard (Squamata: Dactyloidae). Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AbstractCryptic species – genetically distinct species that are morphologically difficult to distinguish – present challenges to systematists. Operationally, cryptic species are very difficult to identify and sole use of genetic data or morphological data can fail to recognize evolutionarily isolated lineages. We use morphometric data to test species boundaries hypothesized with genetic data in the North Caribbean bark anole (Anolis distichus), a suspected species complex. We use univariate and multivariate analyses to test if candidate species based on genetic data can be accurately diagnosed. We also test alternative species delimitation scenarios with a model fitting approach that evaluates normal mixture models capable of identifying morphological clusters. Our analyses reject the hypothesis that the candidate species are diagnosable. Neither uni- nor multivariate morphometric data distinguish candidate species. The best-supported model included two morphological clusters; however, these clusters were uneven and did not align with a plausible species divergence scenario. After removing two related traits driving this result, only one cluster was supported. Despite substantial differentiation revealed by genetic data, we recover no new evidence to delimit species and refrain from taxonomic revision. This study highlights the importance of considering other types of data along with molecular data when delimiting species.
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Affiliation(s)
- Tanner C Myers
- Department of Biological Sciences & Museum of Natural History, Auburn University, Auburn, AL, USA
| | - Pietro L H de Mello
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
- Herpetology Division, Biodiversity Institute, University of Kansas, Lawrence, KS, USA
| | - Richard E Glor
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
- Herpetology Division, Biodiversity Institute, University of Kansas, Lawrence, KS, USA
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Gray LN, Barley AJ, Hillis DM, Pavón‐Vázquez CJ, Poe S, White BA. Does breeding season variation affect evolution of a sexual signaling trait in a tropical lizard clade? Ecol Evol 2020; 10:3738-3746. [PMID: 32313632 PMCID: PMC7160170 DOI: 10.1002/ece3.6167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/04/2020] [Accepted: 02/18/2020] [Indexed: 12/30/2022] Open
Abstract
Sexually selected traits can be expected to increase in importance when the period of sexual behavior is constrained, such as in seasonally restricted breeders. Anolis lizard male dewlaps are classic examples of multifaceted signaling traits, with demonstrated intraspecific reproductive function reflected in courtship behavior. Fitch and Hillis found a correlation between dewlap size and seasonality in mainland Anolis using traditional statistical methods and suggested that seasonally restricted breeding seasons enhanced the differentiation of this signaling trait. Here, we present two tests of the Fitch-Hillis Hypothesis using new phylogenetic and morphological data sets for 44 species of Mexican Anolis. A significant relationship between dewlap size and seasonality is evident in phylogenetically uncorrected analyses but erodes once phylogeny is accounted for. This loss of strong statistical support for a relationship between a key aspect of dewlap morphology and seasonality also occurs within a species complex (A. sericeus group) that inhabits seasonal and aseasonal environments. Our results fail to support seasonality as a strong driver of evolution of Anolis dewlap size. We discuss the implications of our results and the difficulty of disentangling the strength of single mechanisms on trait evolution when multiple selection pressures are likely at play.
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Affiliation(s)
- Levi N. Gray
- Department of BiologyUniversity of New MexicoAlbuquerqueNMUSA
| | | | - David M. Hillis
- Department of Integrative BiologyUniversity of TexasAustinTXUSA
| | | | - Steven Poe
- Department of BiologyUniversity of New MexicoAlbuquerqueNMUSA
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8
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MacGuigan DJ, Geneva AJ, Glor RE. A genomic assessment of species boundaries and hybridization in a group of highly polymorphic anoles ( distichus species complex). Ecol Evol 2017; 7:3657-3671. [PMID: 28616163 PMCID: PMC5468153 DOI: 10.1002/ece3.2751] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/12/2016] [Accepted: 12/22/2016] [Indexed: 02/05/2023] Open
Abstract
Delimiting young species is one of the great challenges of systematic biology, particularly when the species in question exhibit little morphological divergence. Anolis distichus, a trunk anole with more than a dozen subspecies that are defined primarily by dewlap color, may actually represent several independent evolutionary lineages. To test this, we utilized amplified fragment length polymorphisms (AFLP) genome scans and genetic clustering analyses in conjunction with a coalescent‐based species delimitation method. We examined a geographically widespread set of samples and two heavily sampled hybrid zones. We find that genetic divergence is associated with a major biogeographic barrier, the Hispaniolan paleo‐island boundary, but not with dewlap color. Additionally, we find support for hypotheses regarding colonization of two Hispaniolan satellite islands and the Bahamas from mainland Hispaniola. Our results show that A. distichus is composed of seven distinct evolutionary lineages still experiencing a limited degree of gene flow. We suggest that A. distichus merits taxonomic revision, but that dewlap color cannot be relied upon as the primary diagnostic character.
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Affiliation(s)
- Daniel J MacGuigan
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Anthony J Geneva
- Department of Organismic and Evolutionary Biology Harvard University Cambridge MA USA
| | - Richard E Glor
- Herpetology Division Biodiversity Institute University of Kansas Lawrence KS USA.,Department of Ecology and Evolutionary Biology University of Kansas Lawrence KS USA
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Brown RP, Paterson S, Risse J. Genomic Signatures of Historical Allopatry and Ecological Divergence in an Island Lizard. Genome Biol Evol 2016; 8:3618-3626. [PMID: 28040775 PMCID: PMC5203796 DOI: 10.1093/gbe/evw268] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Geographical variation among contiguous populations is frequently attributed to ecological divergence or historical isolation followed by secondary contact. Distinguishing between these effects is key to studies of incipient speciation and could be revealed by different genomic signatures. We used RAD-seq analyses to examine morphologically divergent populations of the endemic lizard (Gallotia galloti) from the volcanic island of Tenerife. Previous analyses have suggested ecological and historical causes to explain the morphological diversity. Analyses of 276,483 single nucleotide polymorphisms (SNPs) from >20 Mbp of the genome revealed one genetically divergent population from Anaga, a region associated with divergent mtDNA lineages in other Tenerife endemics. This population also has a high number of private alleles, and its divergence can be explained by historical isolation. Bayesian outlier analyses identified a small proportion of SNPs as candidates for selection (0.04%) which were strongly differentiated between xeric and mesic habitat types. Individual testing for specific xeric–mesic selection using an alternative approach also supported ecological divergence in a similarly small proportion of SNPs. The study indicates the roles of both historical isolation and ecological divergence in shaping genomic diversity in G. galloti. However, north–south morphological divergence appears solely associated with the latter and likely involves a relatively small proportion of the genome.
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Affiliation(s)
- Richard P Brown
- School of Natural Sciences & Psychology, Liverpool John Moores University, Liverpool, United Kingdom
| | - Steve Paterson
- Department of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Judith Risse
- Department of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
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