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Brennan IG, Chapple DG, Keogh JS, Donnellan S. Evolutionary bursts drive morphological novelty in the world's largest skinks. Curr Biol 2024; 34:3905-3916.e5. [PMID: 39137786 DOI: 10.1016/j.cub.2024.07.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 06/26/2024] [Accepted: 07/09/2024] [Indexed: 08/15/2024]
Abstract
Animal phenotypes evolve and diverge as a result of differing selective pressures and drift. These processes leave unique signatures in patterns of trait evolution, impacting the tempo and mode of morphological macroevolution. While there is a broad understanding of the history of some organismal traits (e.g., body size), there is little consensus about the evolutionary mode of most others. This includes the relative contribution of prolonged (Darwinian gradualist) and episodic (Simpsonian jump) changes toward the evolution of novel morphologies. Here, we use new exon-capture and linear morphological datasets to investigate the tempo and mode of morphological evolution in Australo-Melanesian Tiliquini skinks. We generate a well-supported time-calibrated phylogenomic tree from ∼400 nuclear markers for more than 100 specimens, including undescribed diversity, and provide unprecedented resolution of the rapid Miocene diversification of these lizards. By collecting a morphological dataset that encompasses the lizard body plan (19 traits across the head, body, limb, and tail), we are able to identify that most traits evolve conservatively, but infrequent evolutionary bursts result in morphological novelty. These phenotypic discontinuities occur via rapid rate increases along individual branches, inconsistent with both gradualistic and punctuated equilibrial evolutionary modes. Instead, this "punctuated gradualism" has resulted in the rapid evolution of blue-tongued giants and armored dwarves in the ∼20 million years since colonizing Australia. These results outline the evolutionary pathway toward new morphologies and highlight the heterogeneity of evolutionary tempo and mode, even within individual traits.
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Affiliation(s)
- Ian G Brennan
- Natural History Museum, Cromwell Road, London SW7 5BD, UK; Australian National University, Division of Ecology & Evolution, Linnaeus Way, Canberra, ACT 2600, Australia.
| | - David G Chapple
- Monash University, School of Biological Sciences, Wellington Road, Melbourne, VIC 3800, Australia
| | - J Scott Keogh
- Australian National University, Division of Ecology & Evolution, Linnaeus Way, Canberra, ACT 2600, Australia
| | - Stephen Donnellan
- The University of Adelaide, School of Biological Sciences, North Terrace, Adelaide, SA 5005, Australia; South Australian Museum, North Terrace, Adelaide, SA 5000, Australia; Australian Museum, Australian Museum Research Institute, William Street, Sydney, NSW 2010, Australia
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2
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Abstract
AbstractEvolvability is best addressed from a multi-level, macroevolutionary perspective through a comparative approach that tests for among-clade differences in phenotypic diversification in response to an opportunity, such as encountered after a mass extinction, entering a new adaptive zone, or entering a new geographic area. Analyzing the dynamics of clades under similar environmental conditions can (partially) factor out shared external drivers to recognize intrinsic differences in evolvability, aiming for a macroevolutionary analog of a common-garden experiment. Analyses will be most powerful when integrating neontological and paleontological data: determining differences among extant populations that can be hypothesized to generate large-scale, long-term contrasts in evolvability among clades; or observing large-scale differences among clade histories that can by hypothesized to reflect contrasts in genetics and development observed directly in extant populations. However, many comparative analyses can be informative on their own, as explored in this overview. Differences in clade-level evolvability can be visualized in diversity-disparity plots, which can quantify positive and negative departures of phenotypic productivity from stochastic expectations scaled to taxonomic diversification. Factors that evidently can promote evolvability include modularity—when selection aligns with modular structure or with morphological integration patterns; pronounced ontogenetic changes in morphology, as in allometry or multiphase life cycles; genome size; and a variety of evolutionary novelties, which can also be evaluated using macroevolutionary lags between the acquisition of a trait and phenotypic diversification, and dead-clade-walking patterns that may signal a loss of evolvability when extrinsic factors can be excluded. High speciation rates may indirectly foster phenotypic evolvability, and vice versa. Mechanisms are controversial, but clade evolvability may be higher in the Cambrian, and possibly early in the history of clades at other times; in the tropics; and, for marine organisms, in shallow-water disturbed habitats.
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Vermeij GJ. The ecology of marine colonization by terrestrial arthropods. ARTHROPOD STRUCTURE & DEVELOPMENT 2020; 56:100930. [PMID: 32200289 DOI: 10.1016/j.asd.2020.100930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/24/2020] [Accepted: 02/27/2020] [Indexed: 06/10/2023]
Abstract
Terrestrial arthropods often colonized and became important in freshwater ecosystems, but did so less often and with little consequence in marine habitats. This pattern cannot be explained by the physical properties of water alone or by limitations of the terrestrial arthropod body plan alone. One hypothesis is that transitions among terrestrial, aquatic and marine ecosystems are unlikely when well-adapted incumbent species in the recipient realm collectively resist entry by initially less well adapted newcomers. I evaluated and modified this hypothesis by examining the properties of donor and recipient ecosystems and the roles that insects play or do not play in each. I argue that the insularity and diminished competitiveness of most freshwater ecosystems makes them vulnerable to invasion from land and sea, and largely prevent transitions from freshwater to terrestrial and marine habitats by arthropods. Small terrestrial arthropods emphasize high locomotor performance and long-distance communication, traits that work less well in the denser, more viscous medium of water. These limitations pose particular challenges for insects colonizing highly escalated marine ecosystems, where small incumbent species rely more on passive than on active defences. Predatory insects are less constrained than herbivores, wood-borers, filter-feeders, sediment burrowers and social species.
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Affiliation(s)
- Geerat J Vermeij
- Dept. Earth and Planetary Sciences, University of California, 1 Shields Ave., Davis, CA, 95616, USA.
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Thomson TJ. Three-Legged Locomotion and the Constraints on Limb Number: Why Tripeds Don't Have a Leg to Stand On. Bioessays 2019; 41:e1900061. [PMID: 31531902 DOI: 10.1002/bies.201900061] [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: 04/03/2019] [Revised: 07/06/2019] [Indexed: 11/09/2022]
Abstract
Three-legged animals do not exist today and such an animal is not found in the fossil record. Which constraints operate to result in the lack of a triped phenotype? Consideration of animal locomotion and robotic studies suggests that physical constraints would not prevent a triped from being functional or advantageous. As is reviewed here, the strongest constraint on the evolution of a triped is phylogenetic: namely, the early genetic adoption of a bilaterally symmetrical body plan occurring before the advent of limbs. Presumably, this would greatly constrain any three-legged animal from ever evolving. Tripedalism is employed only by a few animals, but many use a tripod stance while engaged in a variety of activities. Because terms are often used interchangeably in the literature, a standardization of locomotion terminology is proposed. Understanding the constraints behind "forbidden" phenotypes forces us to confront gaps in our evolutionary understanding of which we may be unaware.
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Affiliation(s)
- Tracy J Thomson
- 2119 Earth and Planetary Sciences, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
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Burress ED, Tan M, Wainwright PC. Head Shape Modulates Diversification of a Classic Cichlid Pharyngeal Jaw Innovation. Am Nat 2019; 194:693-706. [PMID: 31613667 DOI: 10.1086/705392] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Functional innovations are often invoked to explain the uneven distribution of ecological diversity. Innovations may provide access to new adaptive zones by expanding available ecological opportunities and may serve as catalysts of adaptive radiation. However, diversity is often unevenly distributed within clades that share a key innovation, highlighting the possibility that the impact of the innovation is mediated by other traits. Pharyngognathy is a widely recognized innovation of the pharyngeal jaws that enhances the ability to process hard and tough prey in several major radiations of fishes, including marine wrasses and freshwater cichlids. We explored diversification of lower pharyngeal jaw shape, a key feature of pharyngognathy, and the extent to which it is influenced by head shape in Neotropical cichlids. While pharyngeal jaw shape was unaffected by either head length or head depth, its disparity declined dramatically with increasing head width. Head width also predicted the rate of pharyngeal jaw evolution such that higher rates were associated with narrow heads. Wide heads are associated with exploiting prey that require intense processing by pharyngeal jaws that have expanded surfaces for the attachment of enlarged muscles. However, we show that a wide head constrains access to adaptive peaks associated with several trophic roles. A constraint on the independent evolution of pharyngeal jaw and head shape may explain the uneven distribution of ecological diversity within a clade that shares a major functional innovation.
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Affiliation(s)
- David Jablonski
- Department of Geophysical Sciences University of Chicago Chicago Illinois
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Vermeij GJ. How convergent are Lake Tanganyika’s gastropods to marine ones? Comparative ecology and adaptive morphology. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Geerat J Vermeij
- University of California, Davis, Department of Earth and Planetary Sciences, Davis, CA, USA
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Luque J, Feldmann RM, Vernygora O, Schweitzer CE, Cameron CB, Kerr KA, Vega FJ, Duque A, Strange M, Palmer AR, Jaramillo C. Exceptional preservation of mid-Cretaceous marine arthropods and the evolution of novel forms via heterochrony. SCIENCE ADVANCES 2019; 5:eaav3875. [PMID: 31032408 PMCID: PMC6482010 DOI: 10.1126/sciadv.aav3875] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 03/06/2019] [Indexed: 06/09/2023]
Abstract
Evolutionary origins of novel forms are often obscure because early and transitional fossils tend to be rare, poorly preserved, or lack proper phylogenetic contexts. We describe a new, exceptionally preserved enigmatic crab from the mid-Cretaceous of Colombia and the United States, whose completeness illuminates the early disparity of the group and the origins of novel forms. Its large and unprotected compound eyes, small fusiform body, and leg-like mouthparts suggest larval trait retention into adulthood via heterochronic development (pedomorphosis), while its large oar-like legs represent the earliest known adaptations in crabs for active swimming. Our phylogenetic analyses, including representatives of all major lineages of fossil and extant crabs, challenge conventional views of their evolution by revealing multiple convergent losses of a typical "crab-like" body plan since the Early Cretaceous. These parallel morphological transformations may be associated with repeated invasions of novel environments, including the pelagic/necto-benthic zone in this pedomorphic chimera crab.
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Affiliation(s)
- J. Luque
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá
- Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109, USA
| | - R. M. Feldmann
- Department of Geology, Kent State University, Kent, OH 44242, USA
| | - O. Vernygora
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - C. E. Schweitzer
- Department of Geology, Kent State University at Stark, 6000 Frank Ave. NW, North Canton, OH 44720, USA
| | - C. B. Cameron
- Département de Sciences Biologiques Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - K. A. Kerr
- Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá
- Canadian Parks and Wilderness Society (CPAWS) Northern Alberta, P.O. Box 52031, Edmonton, AB T6G 2T5, Canada
| | - F. J. Vega
- Instituto de Geología, Universidad Autónoma de México, Ciudad Universitaria, México, CDMX 04510, México
| | - A. Duque
- Computer Animation and Visual Effects, College of Communication and Design, Lynn University, 2601 North Military Trail, Boca Raton, FL 33431, USA
| | - M. Strange
- Department of Geoscience, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, NV 89154-4010, USA
| | - A. R. Palmer
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - C. Jaramillo
- Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá
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Kingston ACN, Sigwart JD, Chappell DR, Speiser DI. Monster or multiplacophoran: A teratological specimen of the chiton
Acanthopleura granulata
(Mollusca: Polyplacophora) with a valve split into independent and symmetrical halves. ACTA ZOOL-STOCKHOLM 2019. [DOI: 10.1111/azo.12289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Daniel R. Chappell
- Department of Biological Sciences University of South Carolina Columbia South Carolina
| | - Daniel I. Speiser
- Department of Biological Sciences University of South Carolina Columbia South Carolina
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10
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Memar N, Schiemann S, Hennig C, Findeis D, Conradt B, Schnabel R. Twenty million years of evolution: The embryogenesis of four Caenorhabditis species are indistinguishable despite extensive genome divergence. Dev Biol 2019; 447:182-199. [DOI: 10.1016/j.ydbio.2018.12.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 12/19/2022]
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Aguilar‐Puntriano C, Avila LJ, De la Riva I, Johnson L, Morando M, Troncoso‐Palacios J, Wood PL, Sites JW. The shadow of the past: Convergence of young and old South American desert lizards as measured by head shape traits. Ecol Evol 2018; 8:11399-11409. [PMID: 30598744 PMCID: PMC6303702 DOI: 10.1002/ece3.4548] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/31/2018] [Accepted: 08/07/2018] [Indexed: 11/17/2022] Open
Abstract
Convergence is a pervasive phenomenon in the Tree of Life, and evolution of similar phenotypes sharing the same environmental conditions is expected in phylogenetically closely related species. In contrast, contingent factors are probably more influential in shaping phenotypic diversity for distantly related taxa. Here, we test putative convergent evolution of lizard head morphologies among relatively closely related desert dwelling Liolaemus species, and the very distantly related Ctenoblepharys adspersa. We estimated a multilocus time-calibrated phylogeny of 57 species of South American liolaemus lizards, based on seven molecular markers. We collected head shape data for 468 specimens, and used three phylogenetic comparative methods (SURFACE, CONVEVOL, and WHEATSHEAF index) to test for and estimate the strength of convergence. We found strong evidence for convergence among Pacific desert lizard C. adspersa, Liolaemus audivetulatus, Liolaemus insolitus, Liolaemus poconchilensis, Liolaemus stolzmanni, and a candidate species (Liolaemus "Moquegua"). Our results suggest that, despite the long divergence and phylogenetic distance of C. adspersa with respect to convergent Liolaemus species, natural selection was probably more important than historical contingency in shaping phenotypic evolution in these desert lizards.
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Affiliation(s)
- César Aguilar‐Puntriano
- Departamento de HerpetologíaMuseo de Historia Natural de San Marcos (MUSM)LimaPerú
- Instituto Antonio Raimondi, Facultad de Ciencias BiológicasUniversidad Nacional Mayor de San Marcos (UNMSM)LimaPerú
| | - Luciano J. Avila
- Instituto Patagónico para el Estudio de los Ecosistemas Continentales (IPEEC‐CONICET)Puerto Madryn, ChubutArgentina
| | | | - Leigh Johnson
- Department of Biology, M. L. Bean Life Science MuseumBrigham Young University (BYU)ProvoUtah
| | - Mariana Morando
- Instituto Patagónico para el Estudio de los Ecosistemas Continentales (IPEEC‐CONICET)Puerto Madryn, ChubutArgentina
| | - Jaime Troncoso‐Palacios
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas (ICBM), Facultad de MedicinaUniversidad de ChileSantiagoChile
| | - Perry L. Wood
- Biodiversity Institute, Department of Ecology and Evolutionary BiologyThe University of KansasLawrenceKansas
| | - Jack W. Sites
- Department of Biology, M. L. Bean Life Science MuseumBrigham Young University (BYU)ProvoUtah
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12
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Galis F, Metz JA, van Alphen JJ. Development and Evolutionary Constraints in Animals. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2018. [DOI: 10.1146/annurev-ecolsys-110617-062339] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We review the evolutionary importance of developmental mechanisms in constraining evolutionary changes in animals—in other words, developmental constraints. We focus on hard constraints that can act on macroevolutionary timescales. In particular, we discuss the causes and evolutionary consequences of the ancient metazoan constraint that differentiated cells cannot divide and constraints against changes of phylotypic stages in vertebrates and other higher taxa. We conclude that in all cases these constraints are caused by complex and highly controlled global interactivity of development, the disturbance of which has grave consequences. Mutations that affect such global interactivity almost unavoidably have many deleterious pleiotropic effects, which will be strongly selected against and will lead to long-term evolutionary stasis. The discussed developmental constraints have pervasive consequences for evolution and critically restrict regeneration capacity and body plan evolution.
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Affiliation(s)
- Frietson Galis
- Naturalis Biodiversity Center, 2333 CR Leiden, The Netherlands
| | - Johan A.J. Metz
- Naturalis Biodiversity Center, 2333 CR Leiden, The Netherlands
- International Institute for Applied Systems Analysis, A-2361 Laxenburg, Austria
- Mathematical Institute, University of Leiden; 2333 CA Leiden, The Netherlands
| | - Jacques J.M. van Alphen
- Naturalis Biodiversity Center, 2333 CR Leiden, The Netherlands
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE Amsterdam, The Netherlands
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Haag ES, Fitch DHA, Delattre M. From "the Worm" to "the Worms" and Back Again: The Evolutionary Developmental Biology of Nematodes. Genetics 2018; 210:397-433. [PMID: 30287515 PMCID: PMC6216592 DOI: 10.1534/genetics.118.300243] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 08/03/2018] [Indexed: 12/13/2022] Open
Abstract
Since the earliest days of research on nematodes, scientists have noted the developmental and morphological variation that exists within and between species. As various cellular and developmental processes were revealed through intense focus on Caenorhabditis elegans, these comparative studies have expanded. Within the genus Caenorhabditis, they include characterization of intraspecific polymorphisms and comparisons of distinct species, all generally amenable to the same laboratory culture methods and supported by robust genomic and experimental tools. The C. elegans paradigm has also motivated studies with more distantly related nematodes and animals. Combined with improved phylogenies, this work has led to important insights about the evolution of nematode development. First, while many aspects of C. elegans development are representative of Caenorhabditis, and of terrestrial nematodes more generally, others vary in ways both obvious and cryptic. Second, the system has revealed several clear examples of developmental flexibility in achieving a particular trait. This includes developmental system drift, in which the developmental control of homologous traits has diverged in different lineages, and cases of convergent evolution. Overall, the wealth of information and experimental techniques developed in C. elegans is being leveraged to make nematodes a powerful system for evolutionary cellular and developmental biology.
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Affiliation(s)
- Eric S Haag
- Department of Biology, University of Maryland, College Park, Maryland 20742
| | | | - Marie Delattre
- Laboratoire de Biologie Moléculaire de la Cellule, CNRS, INSERM, Ecole Normale Supérieure de Lyon, 69007, France
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How the Land Became the Locus of Major Evolutionary Innovations. Curr Biol 2017; 27:3178-3182.e1. [DOI: 10.1016/j.cub.2017.08.076] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 08/29/2017] [Accepted: 08/31/2017] [Indexed: 11/23/2022]
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15
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Jablonski D. Approaches to Macroevolution: 1. General Concepts and Origin of Variation. Evol Biol 2017; 44:427-450. [PMID: 29142333 PMCID: PMC5661017 DOI: 10.1007/s11692-017-9420-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 05/26/2017] [Indexed: 12/11/2022]
Abstract
Approaches to macroevolution require integration of its two fundamental components, i.e. the origin and the sorting of variation, in a hierarchical framework. Macroevolution occurs in multiple currencies that are only loosely correlated, notably taxonomic diversity, morphological disparity, and functional variety. The origin of variation within this conceptual framework is increasingly understood in developmental terms, with the semi-hierarchical structure of gene regulatory networks (GRNs, used here in a broad sense incorporating not just the genetic circuitry per se but the factors controlling the timing and location of gene expression and repression), the non-linear relation between magnitude of genetic change and the phenotypic results, the evolutionary potential of co-opting existing GRNs, and developmental responsiveness to nongenetic signals (i.e. epigenetics and plasticity), all requiring modification of standard microevolutionary models, and rendering difficult any simple definition of evolutionary novelty. The developmental factors underlying macroevolution create anisotropic probabilities-i.e., an uneven density distribution-of evolutionary change around any given phenotypic starting point, and the potential for coordinated changes among traits that can accommodate change via epigenetic mechanisms. From this standpoint, "punctuated equilibrium" and "phyletic gradualism" simply represent two cells in a matrix of evolutionary models of phenotypic change, and the origin of trends and evolutionary novelty are not simply functions of ecological opportunity. Over long timescales, contingency becomes especially important, and can be viewed in terms of macroevolutionary lags (the temporal separation between the origin of a trait or clade and subsequent diversification); such lags can arise by several mechanisms: as geological or phylogenetic artifacts, or when diversifications require synergistic interactions among traits, or between traits and external events. The temporal and spatial patterns of the origins of evolutionary novelties are a challenge to macroevolutionary theory; individual events can be described retrospectively, but a general model relating development, genetics, and ecology is needed. An accompanying paper (Jablonski in Evol Biol 2017) reviews diversity dynamics and the sorting of variation, with some general conclusions.
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Affiliation(s)
- David Jablonski
- Department of Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 USA
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16
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Vermeij GJ. Plant defences on land and in water: why are they so different? ANNALS OF BOTANY 2016; 117:1099-109. [PMID: 27091505 PMCID: PMC4904178 DOI: 10.1093/aob/mcw061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 02/22/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Plants (attached photosynthesizing organisms) are eaten by a wide variety of herbivorous animals. Despite a vast literature on plant defence, contrasting patterns of antiherbivore adaptation among marine, freshwater and land plants have been little noticed, documented or understood. SCOPE Here I show how the surrounding medium (water or air) affects not only the plants themselves, but also the sensory and locomotor capacities of herbivores and their predators, and I discuss patterns of defence and host specialization of plants and herbivores on land and in water. I analysed the literature on herbivory with special reference to mechanical defences and sensory cues emitted by plants. Spines, hairs, asymmetrically oriented features on plant surfaces, and visual and olfactory signals that confuse or repel herbivores are common in land plants but rare or absent in water-dwelling plants. Small terrestrial herbivores are more often host-specific than their aquatic counterparts. I propose that patterns of selection on terrestrial herbivores and plants differ from those on aquatic species. Land plants must often attract animal dispersers and pollinators that, like their herbivorous counterparts, require sophisticated locomotor and sensory abilities. Plants counter their attractiveness to animal helpers by evolving effective contact defences and long-distance cues that mislead or warn herbivores. The locomotor and sensory world of small aquatic herbivores is more limited. These characteristics result from the lower viscosity and density of air compared with water as well as from limitations on plant physiology and signal transmission in water. Evolutionary innovations have not eliminated the contrasts in the conditions of life between water and land. CONCLUSION Plant defence can be understood fully when herbivores and their victims are considered in the broader context of other interactions among coexisting species and of the medium in which these interactions occur.
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Affiliation(s)
- Geerat J Vermeij
- University of California, Davis, Department of Earth and Planetary Sciences, One Shields Avenue, Davis, CA 95616, USA
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17
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Abstract
Should the tape of life be replayed, would it produce similar living beings? A classical answer has long been ‘no’, but accumulating data are now challenging this view. Repeatability in experimental evolution, in phenotypic evolution of diverse species and in the genes underlying phenotypic evolution indicates that despite unpredictability at the level of basic evolutionary processes (such as apparition of mutations), a certain kind of predictability can emerge at higher levels over long time periods. For instance, a survey of the alleles described in the literature that cause non-deleterious phenotypic differences among animals, plants and yeasts indicates that similar phenotypes have often evolved in distinct taxa through independent mutations in the same genes. Does this mean that the range of possibilities for evolution is limited? Does this mean that we can predict the outcomes of a replayed tape of life? Imagining other possible paths for evolution runs into four important issues: (i) resolving the influence of contingency, (ii) imagining living organisms that are different from the ones we know, (iii) finding the relevant concepts for predicting evolution, and (iv) estimating the probability of occurrence for complex evolutionary events that occurred only once during the evolution of life on earth.
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Affiliation(s)
- Virginie Orgogozo
- CNRS, UMR7592, Institut Jacques Monod , Univ Paris Diderot, Sorbonne Paris Cité , 15 rue Hélène Brion, 75013 Paris , France
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18
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Conway Morris S, Hoyal Cuthill JF, Gerber S. Hunting Darwin's Snark: which maps shall we use? Interface Focus 2015. [DOI: 10.1098/rsfs.2015.0078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The 11 contributions to this thematic volume touch on a large range of issues concerning the landscape of biological possibilities and the manner by which it may be traversed by evolving life forms. The contributors also consider how this landscape might be mapped by evolutionary biologists, with an emphasis on how one might identify the limits of such maps. While some agreements emerge on the question of limits on evolution, not surprisingly few contributors look towards the same horizons. Rather than providing a potted summary of the 11 papers, our aim in this introduction is to identify eight principal themes that might serve as common ground and, as importantly, to listen out for the sound of rushing subterranean waters that hint at caverns of concealed knowledge. By no means all of these themes are addressed by all authors, but in gathering the many strands of enquiry we hope that this will allow us to ask: What, if any, are the limits to evolution?
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Affiliation(s)
- Simon Conway Morris
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
| | | | - Sylvain Gerber
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
- National Museum of Natural History, Paris, France
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