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The evolution of siphonophore tentilla for specialized prey capture in the open ocean. Proc Natl Acad Sci U S A 2021; 118:2005063118. [PMID: 33593896 PMCID: PMC7923536 DOI: 10.1073/pnas.2005063118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Predatory specialization is often associated with the evolution of modifications in the morphology of the prey-capture apparatus. Specialization has been considered an evolutionary “dead end” due to the constraints associated with these morphological changes. However, in predators like siphonophores, armed with modular structures used exclusively for prey capture, this assumption is challenged. Our results show that siphonophores can evolve generalism and new prey-type specializations by modifying the morphological states, modes of evolution, and evolutionary correlations between the parts of their prey-capture apparatus. These findings demonstrate how studying open-ocean nonbilaterian predators can reveal novel patterns and mechanisms in the evolution of specialization. Understanding these evolutionary processes is fundamental to the study of food web structure and complexity. Predator specialization has often been considered an evolutionary “dead end” due to the constraints associated with the evolution of morphological and functional optimizations throughout the organism. However, in some predators, these changes are localized in separate structures dedicated to prey capture. One of the most extreme cases of this modularity can be observed in siphonophores, a clade of pelagic colonial cnidarians that use tentilla (tentacle side branches armed with nematocysts) exclusively for prey capture. Here we study how siphonophore specialists and generalists evolve, and what morphological changes are associated with these transitions. To answer these questions, we: a) Measured 29 morphological characters of tentacles from 45 siphonophore species, b) mapped these data to a phylogenetic tree, and c) analyzed the evolutionary associations between morphological characters and prey-type data from the literature. Instead of a dead end, we found that siphonophore specialists can evolve into generalists, and that specialists on one prey type have directly evolved into specialists on other prey types. Our results show that siphonophore tentillum morphology has strong evolutionary associations with prey type, and suggest that shifts between prey types are linked to shifts in the morphology, mode of evolution, and evolutionary correlations of tentilla and their nematocysts. The evolutionary history of siphonophore specialization helps build a broader perspective on predatory niche diversification via morphological innovation and evolution. These findings contribute to understanding how specialization and morphological evolution have shaped present-day food webs.
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Seabolt MH, Alderisio KA, Xiao L, Roellig DM. Prevalence and molecular characterization of novel species of the Diplomonad genus Octomitus (Diplomonadida: Giardiinae) from wildlife in a New York watershed. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2021; 14:267-272. [PMID: 33898227 PMCID: PMC8056139 DOI: 10.1016/j.ijppaw.2021.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/08/2021] [Accepted: 03/08/2021] [Indexed: 11/28/2022]
Abstract
Octomitus is a diplomonad genus known to inhabit the intestinal tracts of rodents. Ultrastructural morphology and 18S rDNA gene sequence analysis support the placement of Octomitus as the closest sister lineage to Giardia, a parasite which causes diarrheal disease in humans and animals worldwide. However, further information on the ecology and diversity of Octomitus is currently scarce. Expanding the available database of characterized sequences for this organism would therefore be helpful to studies of Diplomonad ecology, evolution, and epidemiology, particularly related to the evolution of parasitism in Giardia and Spironucleus, another related Diplomonad common in commercial fish farming. In order to study the prevalence and genotypic diversity of Octomitus, we developed a nested PCR assay specific to Octomitus and optimized to detect genotypes in fecal samples collected from wildlife in a New York watershed, and sequenced a portion of the small subunit ribosomal DNA (18S rDNA) gene to identify samples to species level. Molecular evidence suggested that Octomitus genotypes display similar prevalence to Cryptosporidium and microsporidian pathogens in wildlife as well as strong host preference for rodent and opossum hosts. Phylogenetic analysis showed strong support for 14 Octomitus genotypes, 13 of these novel, and patterns of host-parasite co-evolution. First molecular detection assay for novel Octomitus genotypes. 13 new Octomitus genotypes are identified in diverse rodent hosts and a marsupial. Comparable prevalence of Octomitus in wildlife to Cryptosporidium and microsporidia (24.3%). Octomitus likely has little, if any, public health impact.
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Affiliation(s)
- Matthew H Seabolt
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA.,CFD Research Corporation, Huntsville, AL, 38506, USA
| | - Kerri A Alderisio
- Division of Water Quality Science and Research, Bureau of Water Supply, New York City Department of Environmental Protection, Valhalla, NY, USA
| | - Lihua Xiao
- Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, Guangdong, 510642, China
| | - Dawn M Roellig
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
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3
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Losos JB, Irschick DJ, Schoener TW. ADAPTATION AND CONSTRAINT IN THE EVOLUTION OF SPECIALIZATION OF BAHAMIAN
ANOLIS
LIZARDS. Evolution 2017; 48:1786-1798. [DOI: 10.1111/j.1558-5646.1994.tb02214.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/1993] [Accepted: 02/07/1994] [Indexed: 11/30/2022]
Affiliation(s)
- Jonathan B. Losos
- Department of Biology, Campus Box 1137 Washington University St. Louis Missouri 63130‐4899
| | - Duncan J. Irschick
- Department of Biology, Campus Box 1137 Washington University St. Louis Missouri 63130‐4899
| | - Thomas W. Schoener
- Section of Evolution and Ecology and Center for Population Biology, Storer Hall University of California Davis California 95616
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4
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da Silva-Júnior R, Paiva TDS. Evaluating the role of morphological characters in the phylogeny of some trypanosomatid genera (Excavata, Kinetoplastea, Trypanosomatida). Cladistics 2017; 34:167-180. [DOI: 10.1111/cla.12199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2017] [Indexed: 11/29/2022] Open
Affiliation(s)
- Renato da Silva-Júnior
- Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera; FIOCRUZ; Instituto Oswaldo Cruz; 21040-900 Rio de Janeiro RJ Brazil
- Programa de Pós-graduação em Ciências e Biotecnologia; Universidade Federal Fluminense; Niterói RJ Brazil
| | - Thiago da Silva Paiva
- Laboratory of Evolutionary Protistology; Instituto de Biociências; Universidade de São Paulo; 05508-090 São Paulo SP Brazil
- Laboratório de Biologia Molecular “Francisco Mauro Salzano”; Instituto de Ciências Biológicas; Universidade Federal do Pará; 66075-110 Belém PA Brazil
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5
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Yubuki N, Zadrobílková E, Čepička I. Ultrastructure and Molecular Phylogeny of Iotanema spirale gen. nov. et sp. nov., a New Lineage of Endobiotic Fornicata with Strikingly Simplified Ultrastructure. J Eukaryot Microbiol 2016; 64:422-433. [PMID: 27749017 DOI: 10.1111/jeu.12376] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/30/2016] [Accepted: 10/12/2016] [Indexed: 12/19/2022]
Abstract
Fornicata (Metamonada) is a group of Excavata living in low-oxygen environments and lacking conventional mitochondria. It includes free-living Carpediemonas-like organisms from marine habitats and predominantly parasitic/commensal retortamonads and diplomonads. Current modest knowledge of biodiversity of Fornicata limits our ability to draw a complete picture of the evolutionary history in this group. Here, we report the discovery of a novel fornicate, Iotanema spirale gen. nov. et sp. nov., obtained from fresh feces of the gecko Phelsuma madagascariensis. Our phylogenetic analyses of the small subunit ribosomal RNA gene demonstrate that I. spirale is closely related to the free-living, marine strain PCS and the Carpediemonas-like organism Hicanonectes teleskopos within Fornicata. Iotanema spirale exhibits several features uncommon to fornicates, such as a single flagellum, a highly reduced cytoskeletal system, and the lack of the excavate ventral groove, but shares these characters with the poorly known genus Caviomonas. Therefore, I. spirale is accommodated within the family Caviomonadidae, which represents the third known endobiotic lineage of Fornicata. This study improves our understanding of character evolution within Fornicata when placed within the molecular phylogenetic context.
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Affiliation(s)
- Naoji Yubuki
- Department of Zoology, Faculty of Science, Charles University, Vinicna 7, Prague, 128 44, Czech Republic
| | - Eliška Zadrobílková
- Department of Zoology, Faculty of Science, Charles University, Vinicna 7, Prague, 128 44, Czech Republic.,Centre for Epidemiology and Microbiology, National Institute of Public Health, Srobarova 48, Prague, 100 42, Czech Republic
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Vinicna 7, Prague, 128 44, Czech Republic
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6
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Xu F, Jerlström-Hultqvist J, Kolisko M, Simpson AGB, Roger AJ, Svärd SG, Andersson JO. On the reversibility of parasitism: adaptation to a free-living lifestyle via gene acquisitions in the diplomonad Trepomonas sp. PC1. BMC Biol 2016; 14:62. [PMID: 27480115 PMCID: PMC4967989 DOI: 10.1186/s12915-016-0284-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/13/2016] [Indexed: 01/08/2023] Open
Abstract
Background It is generally thought that the evolutionary transition to parasitism is irreversible because it is associated with the loss of functions needed for a free-living lifestyle. Nevertheless, free-living taxa are sometimes nested within parasite clades in phylogenetic trees, which could indicate that they are secondarily free-living. Herein, we test this hypothesis by studying the genomic basis for evolutionary transitions between lifestyles in diplomonads, a group of anaerobic eukaryotes. Most described diplomonads are intestinal parasites or commensals of various animals, but there are also free-living diplomonads found in oxygen-poor environments such as marine and freshwater sediments. All these nest well within groups of parasitic diplomonads in phylogenetic trees, suggesting that they could be secondarily free-living. Results We present a transcriptome study of Trepomonas sp. PC1, a diplomonad isolated from marine sediment. Analysis of the metabolic genes revealed a number of proteins involved in degradation of the bacterial membrane and cell wall, as well as an extended set of enzymes involved in carbohydrate degradation and nucleotide metabolism. Phylogenetic analyses showed that most of the differences in metabolic capacity between free-living Trepomonas and the parasitic diplomonads are due to recent acquisitions of bacterial genes via gene transfer. Interestingly, one of the acquired genes encodes a ribonucleotide reductase, which frees Trepomonas from the need to scavenge deoxyribonucleosides. The transcriptome included a gene encoding squalene-tetrahymanol cyclase. This enzyme synthesizes the sterol substitute tetrahymanol in the absence of oxygen, potentially allowing Trepomonas to thrive under anaerobic conditions as a free-living bacterivore, without depending on sterols from other eukaryotes. Conclusions Our findings are consistent with the phylogenetic evidence that the last common ancestor of diplomonads was dependent on a host and that Trepomonas has adapted secondarily to a free-living lifestyle. We believe that similar studies of other groups where free-living taxa are nested within parasites could reveal more examples of secondarily free-living eukaryotes. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0284-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Feifei Xu
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Jon Jerlström-Hultqvist
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Present address: Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Martin Kolisko
- Department of Biology, Dalhousie University, Halifax, NS, Canada.,Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.,Present address: Botany Department, University of British Columbia, Vancouver, BC, Canada
| | - Alastair G B Simpson
- Department of Biology, Dalhousie University, Halifax, NS, Canada.,Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, Toronto, ON, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.,Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, Toronto, ON, Canada
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Jan O Andersson
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
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Wang F, Kaplan JL, Gold BD, Bhasin MK, Ward NL, Kellermayer R, Kirschner BS, Heyman MB, Dowd SE, Cox SB, Dogan H, Steven B, Ferry GD, Cohen SA, Baldassano RN, Moran CJ, Garnett EA, Drake L, Otu HH, Mirny LA, Libermann TA, Winter HS, Korolev KS. Detecting Microbial Dysbiosis Associated with Pediatric Crohn Disease Despite the High Variability of the Gut Microbiota. Cell Rep 2016; 14:945-955. [PMID: 26804920 DOI: 10.1016/j.celrep.2015.12.088] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 12/03/2015] [Accepted: 12/18/2015] [Indexed: 02/06/2023] Open
Abstract
The relationship between the host and its microbiota is challenging to understand because both microbial communities and their environments are highly variable. We have developed a set of techniques based on population dynamics and information theory to address this challenge. These methods identify additional bacterial taxa associated with pediatric Crohn disease and can detect significant changes in microbial communities with fewer samples than previous statistical approaches required. We have also substantially improved the accuracy of the diagnosis based on the microbiota from stool samples, and we found that the ecological niche of a microbe predicts its role in Crohn disease. Bacteria typically residing in the lumen of healthy individuals decrease in disease, whereas bacteria typically residing on the mucosa of healthy individuals increase in disease. Our results also show that the associations with Crohn disease are evolutionarily conserved and provide a mutual information-based method to depict dysbiosis.
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Affiliation(s)
- Feng Wang
- Bioinformatics Graduate Program, Boston University, Boston, MA 02215, USA
| | - Jess L Kaplan
- Department of Pediatrics, MassGeneral Hospital for Children, Harvard Medical School, Boston, MA 02114, USA
| | - Benjamin D Gold
- Children's Healthcare of Atlanta, LLC; GI Care for Kids, LLC; Atlanta, GA 30342, USA
| | - Manoj K Bhasin
- BIDMC Genomics, Proteomics, Bioinformatics and Systems Biology Center and Department of Medicine, Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
| | - Naomi L Ward
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA
| | - Richard Kellermayer
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Barbara S Kirschner
- Department of Pediatrics, University of Chicago Comer Children's Hospital, Chicago, IL 60637, USA
| | - Melvin B Heyman
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Scot E Dowd
- Molecular Research MR DNA, Shallowater, TX 79363, USA
| | - Stephen B Cox
- Molecular Research MR DNA, Shallowater, TX 79363, USA
| | - Haluk Dogan
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Blaire Steven
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA
| | - George D Ferry
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Stanley A Cohen
- Children's Healthcare of Atlanta, LLC; GI Care for Kids, LLC; Atlanta, GA 30342, USA
| | - Robert N Baldassano
- Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Christopher J Moran
- Department of Pediatrics, MassGeneral Hospital for Children, Harvard Medical School, Boston, MA 02114, USA
| | - Elizabeth A Garnett
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Lauren Drake
- Department of Pediatrics, MassGeneral Hospital for Children, Harvard Medical School, Boston, MA 02114, USA
| | - Hasan H Otu
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Leonid A Mirny
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Towia A Libermann
- BIDMC Genomics, Proteomics, Bioinformatics and Systems Biology Center and Department of Medicine, Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
| | - Harland S Winter
- Department of Pediatrics, MassGeneral Hospital for Children, Harvard Medical School, Boston, MA 02114, USA.
| | - Kirill S Korolev
- Bioinformatics Graduate Program, Boston University, Boston, MA 02215, USA; Department of Physics, Boston University, Boston, MA 02215, USA.
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8
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Klimov PB, OConnor B. Is permanent parasitism reversible?--critical evidence from early evolution of house dust mites. Syst Biol 2013; 62:411-23. [PMID: 23417682 DOI: 10.1093/sysbio/syt008] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Long-term specialization may limit the ability of a species to respond to new environmental conditions and lead to a higher likelihood of extinction. For permanent parasites and other symbionts, the most intriguing question is whether these organisms can return to a free-living lifestyle and, thus, escape an evolutionary "dead end." This question is directly related to Dollo's law, which stipulates that a complex trait (such as being free living vs. parasitic) cannot re-evolve again in the same form. Here, we present conclusive evidence that house dust mites, a group of medically important free-living organisms, evolved from permanent parasites of warm-blooded vertebrates. A robust, multigene topology (315 taxa, 8942 nt), ancestral character state reconstruction, and a test for irreversible evolution (Dollo's law) demonstrate that house dust mites have abandoned a parasitic lifestyle, secondarily becoming free living, and then speciated in several habitats. Hence, as exemplified by this model system, highly specialized permanent parasites may drastically de-specialize to the extent of becoming free living and, thus escape from dead-end evolution. Our phylogenetic and historical ecological framework explains the limited cross-reactivity between allergens from the house dust mites and "storage" mites and the ability of the dust mites to inhibit host immune responses. It also provides insights into how ancestral features related to parasitism (frequent ancestral shifts to unrelated hosts, tolerance to lower humidity, and pre-existing enzymes targeting skin and keratinous materials) played a major role in reversal to the free-living state. We propose that parasitic ancestors of pyroglyphids shifted to nests of vertebrates. Later the nest-inhabiting pyroglyphids expanded into human dwellings to become a major source of allergens.
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Affiliation(s)
- Pavel B Klimov
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109-1079, USA.
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9
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Prendini L, Francke OF, Vignoli V. Troglomorphism, trichobothriotaxy and typhlochactid phylogeny (Scorpiones, Chactoidea): more evidence that troglobitism is not an evolutionary dead-end. Cladistics 2010; 26:117-142. [DOI: 10.1111/j.1096-0031.2009.00277.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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10
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-Grandcolas L. Studies in cave life evolution: a rationale for future theoretical developments using phylogenetic inference. J ZOOL SYST EVOL RES 2009. [DOI: 10.1111/j.1439-0469.1997.tb00400.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Cruickshank RH, Paterson AM. The great escape: do parasites break Dollo's law? Trends Parasitol 2006; 22:509-15. [PMID: 16971179 DOI: 10.1016/j.pt.2006.08.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 08/03/2006] [Accepted: 08/30/2006] [Indexed: 11/17/2022]
Abstract
A long-held assumption in evolutionary studies is that a character that changes from a complex to a simple state is unlikely to return to the same complex state. The extreme version of this assumption has been codified as Dollo's law. Unfortunately, this paradigm has supported the idea that simple and complex traits are qualitatively different, when it is more sensible to suggest that there is a quantitative difference. Dollo's law has been the predominant paradigm in parasitology, where a move from a free-living state to parasitism has been considered a unidirectional pathway or 'one-way trip' because organisms lose the structures required to return to the free-living state. Several recent studies have suggested that complex structures can be regained from simple traits, and we suggest that this is also possible for parasites.
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Affiliation(s)
- Robert H Cruickshank
- Bio-Protection and Ecology Division, Lincoln University, PO Box 84, Lincoln, Canterbury 7647, New Zealand
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12
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Bert W, Messiaen M, Manhout J, Houthoofd W, Borgonie G. Evolutionary loss of parasitism by nematodes? Discovery of a free-living filaroid nematode. J Parasitol 2006; 92:645-7. [PMID: 16884014 DOI: 10.1645/ge-672r.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A cattle-drinking pool in nature reserve "Zwin" on the Belgian coast contained free-living third-stage infective filaroid juveniles. These juveniles clearly differ morphologically from all known nematodes. Morphological and molecular analyses indicate a position within the Filaroidea. The aberrant biology of this nematode, namely, a free-living stage in an aquatic environment, is unknown within this superfamily, and the evolution of the parasitic phenotype to a free-living state is generally thought to be unlikely. However, the obtained placement in the small subunit molecular phylogenetic tree suggests that this free-living stage is most likely a secondary adaptation. It is reasonable to assert that nematodes with complex life cycles still have the genetic potential for a reversion from parasitism to a (partial) free-living stage.
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Affiliation(s)
- Wim Bert
- Department of Biology, Ghent University, Belgium.
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13
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Stireman JO. The evolution of generalization? Parasitoid flies and the perils of inferring host range evolution from phylogenies. J Evol Biol 2005; 18:325-36. [PMID: 15715839 DOI: 10.1111/j.1420-9101.2004.00850.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is widely assumed that high resource specificity predisposes lineages toward greater likelihood of extinction and lower likelihood of diversification than more generalized lineages. This suggests that host range evolution in parasitic organisms should proceed from generalist to specialist, and specialist lineages should be found at the 'tips' of phylogenies. To test these hypotheses, parsimony and maximum likelihood methods were used to reconstruct the evolution of host range on a phylogeny of parasitoid flies in the family Tachinidae. In contrast to predictions, most reconstructions indicated that generalists were repeatedly derived from specialist lineages and tended to occupy terminal branches of the phylogeny. These results are critically examined with respect to hypotheses concerning the evolution of specialization, the inherent difficulties in inferring host ranges, our knowledge of tachinid-host associations, and the methodological problems associated with ancestral character state reconstruction. Both parsimony and likelihood reconstructions are shown to provide misleading results and it is argued that independent evidence, in addition to phylogenetic trees, is needed to inform models of the evolution of host range and the evolutionary consequences of specialization.
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Affiliation(s)
- J O Stireman
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA.
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14
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Ober KA. ARBOREALITY AND MORPHOLOGICAL EVOLUTION IN GROUND BEETLES (CARABIDAE: HARPALINAE): TESTING THE TAXON PULSE MODEL. Evolution 2003. [DOI: 10.1554/02-532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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D'Haese C. Is Psammophily an Evolutionary Dead End? A Phylogenetic Test in the Genus Willemia (Collembola: Hypogastruridae). Cladistics 2000; 16:255-273. [DOI: 10.1111/j.1096-0031.2000.tb00282.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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16
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Desutter-Grandcolas L. A Phylogenetic Analysis of the Evolution of the Stridulatory Apparatus in True Crickets (Orthoptera, Grylloidea). Cladistics 1997; 13:101-108. [DOI: 10.1111/j.1096-0031.1997.tb00244.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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