DOCSLIB.ORG

Testing the Quality of the Fossil Record by Groups and by Major Habitats

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Testing the Quality of the Fossil Record by Groups and by Major Habitats Histo-icalBiology, 1996, Vol 12,pp I 1I-157 © 1996 OPA (Overseas Publishers Association) Reprints available directly from the publisher Amsterdam B V Published in The Netherlands Photocopying available by license only By Harwood Academic Publishers GmbH Printed in Malaysia TESTING THE QUALITY OF THE FOSSIL RECORD BY GROUPS AND BY MAJOR HABITATS MICHAEL J BENTON and REBECCA HITCHIN Department of Geology, University of Bristol, Bristol, B 58 IRJ, United Kingdom (Received February 9 1996; in final form March 25, 1996) The evolution of life is a form of history and, as Karl Popper pointed out, that makes much of palaeontology and evolutionary biology metaphysical and not scientific, since direct testing is not possible: history cannot be re-run However, it is possible to cross-compare three sources of data on phylogeny stratigraphic, cladistic, and molecular Three metrics for comparing cladograms with stratigraphic information allow cross-testing of () the order of branching with the stratigraphic order of fossils, and of (2) the relative amount of cladistically-implied gap in proportion to known fossil record. Results of the metrics, based upon a data set of 376 cladograms, show that there are statistically significant differences in the results for echinoderms, fishes, and tetrapods Matching of rank- order data on stratigraphic age of first appearances and branching points in cladograms, using Spearman Rank Correlation (SRC), is poorer than reported before, with only 148 of the 376 cladograms tested (39 %) showing statistically significant matching Tests of the relative amount of cladistically-implied gap, using the Relative Completeness Index (RCI), indicated excellent results, with 288 of the cladograms tested (77 %) having records more than 50% complete. Assessment of the Stratigraphic Consistency Index (SCI), the relative number of nodes i a cladogram having younger taxa located above them than immediately below them showed that 79 % of cladograms tested scored over 0 500 This indicates that node order was generally consistent with stratigraphic order of first finds, contrary to the findings of the rather cruder SRC metric. Group-by-group results were variable SRC results, based on significances of age-clade rank order equivalence, were best for tetrapods, moderate for echinoderms, and worst for fishes Best RCI values were for fishes, and poorer for tetrapods and echinoderms SCI values were best for echinoderms, poorer for tetrapods, and poorest for fishes Arbitrary scoring of the three metrics suggests provisionally that the echinoderms and tetrapods have a better fossil record than fishes. Comparison of marine groups (echinoderms + fishes) versus continental groups (tetrapods) showed that many more continental cladograms (50 %) showed significant SRC matching of age and clade order than marine cladograms (25 %) Continental cladograms also yielded higher SCI values, with 87 % achieving values equal to, or higher than, 0 5, while for marine cladograms, the value was 72 % Marine cladograms, on the other hand, scored better for relative completeness, with 79% showing RCI values greater than 50 %, compared to 74 % for continental cladograms The aggregate results suggest that continental cladograms are better than marine cladograms by two metrics (SRC, SCI) to one (RCI). KEY WORDS: Cladistics, phylogeny, stratigraphy, evolution, Popper, fossil record. INTRODUCTION Fossil data offer unique information on evolution, giving the only evidence for the existence of groups that are now extinct, and providing precise data on the order of events in phylogeny Two serious problems with the fossil record have been identified, however, and these must be tackled before palaeontological data can be used III 112 M J BENTON AND R HITCHIN seamlessly in combination with information on living organisms These problems are that ( 1) studies of the history of life may be viewed as non-scientific, as metaphysical (Popper, 1960, 1972, 1976), and that (2) the fossil record is clearly incomplete, but that incompleteness cannot be quantified against an absolute knowledge of the true pattern of the history of life. A potential resolution of these two issues is presented here It is proposed that large parts of Darwinian evolution can be cast in a way that is falsifiable, and phylogeny reconstruction, the methods used to discover the true shape of the history of life, offer means of mutual cross-falsification, a solution to the dilemma that Popper highlighted. The mutual cross-testing approach also offers the opportunity of finding measures of the completeness of the fossil record, in part and in whole. POPPER, EVOLUTION, AND METAPHYSICS Popper (1960, 1972, 1976) charged that the historical sciences, such as the study of the history of life, are metaphysics and not science This is a serious challenge, and potentially damaging to the acceptance of conclusions from large parts of evolutionary biology and palaeontology (Platnick and Gaffney, 1977, 1978 a, 1978 b; Halstead, 1980). Popper based his conclusion on his discovery (Popper, 1959, 1965) of a clear operational demarcation between science and metaphysics: in his terms, scientific theories are capable of falsification, while metaphysical propositions are not. Popper did not use the word 'metaphysics' in a pejorative sense, although many before him and after him have done so, sometimes equating metaphysics with mumbo-jumbo or pseudo-science Indeed, Popper argued very clearly that a theory in metaphysics is not testable, but that does not mean that it is wrong Indeed, in the history of many subjects, what was once metaphysics may become science when the tools or insights become available to design adequate tests that offer the possibility of falsification. Popper considered the nature of Darwinian evolution in various of his writings, but came to the firm conclusion, through a series of his works in which he considered the correct method for studying and analysing history, that evolution is more metaphysics than science Popper ( 1976, p 172) compared the natural theological explanation that nature is perfect because God created it that way, with Darwinian evolution: "Now to the degree that Darwinism creates the same impression, it is not much better than the theistic view of adaptation; it is therefore important to show that Darwinism is not a scientific theory, but metaphysical But its value for science as a metaphysical research programme is very great, especially if it is admitted that it may be criticized, and improved upon " Popper argued that Darwinism was metaphysics, and not science, for two reasons, ( 1) the theory is not testable, and indeed is almost tautological, and (2) the evolution of life happened once, and it is impossible to generalise law-like statements from a single set of events Darwinian evolution is untestable, Popper ( 1976) argued, because it cannot make predictions about what might happen on another planet where life originates The key tenets of Darwinism, natural selection, diversification, and adaptation in a sense simply describe what has happened, and is happening, but these phenomena cannot be framed in a precise way that permits of their falsification. Popper repeats the favourite argument of Creationists that adaptation is virtually a tautologous proposition: adaptation and fitness are defined as survival value, and they can be measured by actual success in survival, but such a definition is virtually untestable The second criticism of evolution was that life has evolved once only, so far as we know, and cannot be tested Hence, the scientist, used to applying the TESTING THE QUALITY OF THE FOSSIL RECORD 113 experimental hypothesis-testing approach is powerless How can a scientific study of phylogeny be instituted if it is impossible to re-run evolutionary history many times, altering variables on each run so that the fundamental principles may be determined? Put another way, and still applying the Popperian method of science, how can evolution be falsified? What single test could be imagined? lThis critique, in simple form, is beloved of creationists, who use it to deny that evolution is scientific l The usual riposte, convincing, but not overwhelming, is that evolution is a complex amalgam of numerous hypotheses, any one of which may be tested, and many of which have been tested repeatedly by evolutionary ecologists, geneticists, palaeobiologists, and systematists. It is important first to divide evolution into two main propositions: ( 1) the assertion that life has evolved (literally 'unrolled') during the course of geological time; and, (2) that evolution has occurred by natural selection As Platnick and Gaffney (1978 a), Patterson (1978), and others have argued, the first proposition probably offers most difficulty Natural selection can be subjected to test in a variety of ways, some of them in the form of short-term laboratory experiments, others by longer-term natural experiments, but all of these are, and have been, repeatable time and time again, with different organisms, and in different settings There is no need to get sucked into the Creationists' tautology'argument, as Popper did (see Ridley, 1993, chapter 3 for an excellent overview). The first proposition, not original to Darwin, simply that life has evolved, from simple to complex organisms, from low to high diversity, and over a long period of time, is at first sight harder to tackle, for the reasons given by Popper Patterson (1978, pp 145-147) accepted Popper's description of evolution as a pattern
Load more

Recommended publications
  • Download Full Article 1.7MB .Pdf File
    https://doi.org/10.24199/j.mmv.1934.8.08 September 1934 Mem. Nat. Mus. Vict., viii, 1934. THE CAINOZOIG CIDARIDAE OF AUSTRALIA. By Frederick Chapman, A.L.S., F.G.S., Commonwealth Palaeon- tologist, and Francis A. Cudmore, Hon. Palaeontologist, National Museum. Plates XII-XV. Nearly 60 years ago Professor P. M. Duncan described the first Australian Cainozoic cidaroid before the Geological Society of London. During the next 20 years Professors R. Tate and J. W. Gregory published references to our fossil cidaroids, but further descriptive work was not attempted until the present authors undertook to examine the accumulated material in the National Museum, the Tate Collection at Adelaide University Museum, the Commonwealth Palaeontological Collection, and the private collections made by the late Dr. T. S. Hall, F. A. Singleton, the Rev. Geo. Cox and the authors. The classification of the Cidaridae is founded mainly upon living species and it is partly based on structures which are only rarely preserved in fossils. Fossil cidaroid tests are usually imperfect. On abraded tests the conjugation of ambulacral pores is obscure. The apical system is preserved only in one specimen among those examined. The spines are rarely attached to the test and pedicellariae are wanting. Therefore, in dealing with our specimens we have been guided mainly by the appear- ance and structure of ambulacral and interambulacral areas. Certain features used in our classification vary with the growth stage of the test : for instance, the number of coronal plates in vertical series, the number of ambulacral plates adjacent to the largest coronal plate, and sometimes the number of granules on the inner end of ambulacral plates.
    [Show full text]
  • SI Appendix for Hopkins, Melanie J, and Smith, Andrew B
    Hopkins and Smith, SI Appendix SI Appendix for Hopkins, Melanie J, and Smith, Andrew B. Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution. Corrections to character matrix Before running any analyses, we corrected a few errors in the published character matrix of Kroh and Smith (1). Specifically, we removed the three duplicate records of Oligopygus, Haimea, and Conoclypus, and removed characters C51 and C59, which had been excluded from the phylogenetic analysis but mistakenly remain in the matrix that was published in Appendix 2 of (1). We also excluded Anisocidaris, Paurocidaris, Pseudocidaris, Glyphopneustes, Enichaster, and Tiarechinus from the character matrix because these taxa were excluded from the strict consensus tree (1). This left 164 taxa and 303 characters for calculations of rates of evolution and for the principal coordinates analysis. Other tree scaling methods The most basic method for scaling a tree using first appearances of taxa is to make each internal node the age of its oldest descendent ("stand") (2), but this often results in many zero-length branches which are both theoretically questionable and in some cases methodologically problematic (3). Several methods exist for modifying zero-length branches. In the case of the results shown in Figure 1, we assigned a positive length to each zero-length branch by having it share time equally with a preceding, non-zero-length branch (“equal”) (4). However, we compared the results from this method of scaling to several other methods. First, we compared this with rates estimated from trees scaled such that zero-length branches share time proportionally to the amount of character change along the branches (“prop”) (5), a variation which gave almost identical results as the method used for the “equal” method (Fig.
    [Show full text]
  • Contributions in BIOLOGY and GEOLOGY
    MILWAUKEE PUBLIC MUSEUM Contributions In BIOLOGY and GEOLOGY Number 51 November 29, 1982 A Compendium of Fossil Marine Families J. John Sepkoski, Jr. MILWAUKEE PUBLIC MUSEUM Contributions in BIOLOGY and GEOLOGY Number 51 November 29, 1982 A COMPENDIUM OF FOSSIL MARINE FAMILIES J. JOHN SEPKOSKI, JR. Department of the Geophysical Sciences University of Chicago REVIEWERS FOR THIS PUBLICATION: Robert Gernant, University of Wisconsin-Milwaukee David M. Raup, Field Museum of Natural History Frederick R. Schram, San Diego Natural History Museum Peter M. Sheehan, Milwaukee Public Museum ISBN 0-893260-081-9 Milwaukee Public Museum Press Published by the Order of the Board of Trustees CONTENTS Abstract ---- ---------- -- - ----------------------- 2 Introduction -- --- -- ------ - - - ------- - ----------- - - - 2 Compendium ----------------------------- -- ------ 6 Protozoa ----- - ------- - - - -- -- - -------- - ------ - 6 Porifera------------- --- ---------------------- 9 Archaeocyatha -- - ------ - ------ - - -- ---------- - - - - 14 Coelenterata -- - -- --- -- - - -- - - - - -- - -- - -- - - -- -- - -- 17 Platyhelminthes - - -- - - - -- - - -- - -- - -- - -- -- --- - - - - - - 24 Rhynchocoela - ---- - - - - ---- --- ---- - - ----------- - 24 Priapulida ------ ---- - - - - -- - - -- - ------ - -- ------ 24 Nematoda - -- - --- --- -- - -- --- - -- --- ---- -- - - -- -- 24 Mollusca ------------- --- --------------- ------ 24 Sipunculida ---------- --- ------------ ---- -- --- - 46 Echiurida ------ - --- - - - - - --- --- - -- --- - -- - - ---
    [Show full text]
  • Copyrighted Material
    06_250317 part1-3.qxd 12/13/05 7:32 PM Page 15 Phylum Chordata Chordates are placed in the superphylum Deuterostomia. The possible rela- tionships of the chordates and deuterostomes to other metazoans are dis- cussed in Halanych (2004). He restricts the taxon of deuterostomes to the chordates and their proposed immediate sister group, a taxon comprising the hemichordates, echinoderms, and the wormlike Xenoturbella. The phylum Chordata has been used by most recent workers to encompass members of the subphyla Urochordata (tunicates or sea-squirts), Cephalochordata (lancelets), and Craniata (fishes, amphibians, reptiles, birds, and mammals). The Cephalochordata and Craniata form a mono- phyletic group (e.g., Cameron et al., 2000; Halanych, 2004). Much disagree- ment exists concerning the interrelationships and classification of the Chordata, and the inclusion of the urochordates as sister to the cephalochor- dates and craniates is not as broadly held as the sister-group relationship of cephalochordates and craniates (Halanych, 2004). Many excitingCOPYRIGHTED fossil finds in recent years MATERIAL reveal what the first fishes may have looked like, and these finds push the fossil record of fishes back into the early Cambrian, far further back than previously known. There is still much difference of opinion on the phylogenetic position of these new Cambrian species, and many new discoveries and changes in early fish systematics may be expected over the next decade. As noted by Halanych (2004), D.-G. (D.) Shu and collaborators have discovered fossil ascidians (e.g., Cheungkongella), cephalochordate-like yunnanozoans (Haikouella and Yunnanozoon), and jaw- less craniates (Myllokunmingia, and its junior synonym Haikouichthys) over the 15 06_250317 part1-3.qxd 12/13/05 7:32 PM Page 16 16 Fishes of the World last few years that push the origins of these three major taxa at least into the Lower Cambrian (approximately 530–540 million years ago).
    [Show full text]
  • Geoconservation in the Cabeço Da Ladeira Paleontological Site
    geosciences Article Geoconservation in the Cabeço da Ladeira Paleontological Site (Serras de Aire e Candeeiros Nature Park, Portugal): Exquisite Preservation of Animals and Their Behavioral Activities in a Middle Jurassic Carbonate Tidal Flat Susana Machado 1,*, Lia Mergulhão 2, Bruno Claro Pereira 3,4,5 , Pedro Pereira 6,7,8 , Jorge Carvalho 1 , José António Anacleto 1,9, Carlos Neto de Carvalho 8,10 , João Belo 11,12, Ricardo Paredes 13,14 and Andrea Baucon 10,15 1 Laboratório Nacional de Energia e Geologia (LNEG), P-2610 999 Amadora, Portugal; [email protected] (J.C.); [email protected] (J.A.A.) 2 Instituto da Conservação da Natureza e das Florestas (ICNF), P-1050 191 Lisbon, Portugal; [email protected] 3 Museu da Lourinhã, P-2530 158 Lourinhã, Portugal; [email protected] 4 Citation: Machado, S.; Mergulhão, Associação Geoparque Oeste, P-2530 103 Lourinhã, Portugal 5 L.; Pereira, B.C.; Pereira, P.; Carvalho, GeoBioTec, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Campus da Caparica, J.; Anacleto, J.A.; Neto de Carvalho, P-2829 516 Caparica, Portugal 6 Department of Sciences and Technology, Universidade Aberta, P-1269 001 Lisbon, Portugal; C.; Belo, J.; Paredes, R.; Baucon, A. [email protected] Geoconservation in the Cabeço da 7 Center for Functional Ecology, Universidade de Coimbra, P-3000 456 Coimbra, Portugal Ladeira Paleontological Site (Serras 8 Instituto Dom Luiz, University of Lisbon, P-1749 016 Lisbon, Portugal; [email protected] de Aire e Candeeiros Nature Park, 9 Museu Geológico do LNEG, P-1249 280 Lisbon, Portugal Portugal): Exquisite Preservation of 10 Naturtejo UNESCO Global Geopark.
    [Show full text]
  • Larval Development of the Tropical Deep-Sea Echinoid Aspidodiademajacobyi: Phylogenetic Implications
    FAU Institutional Repository http://purl.fcla.edu/fau/fauir This paper was submitted by the faculty of FAU’s Harbor Branch Oceanographic Institute. Notice: ©2000 Marine Biological Laboratory. The final published version of this manuscript is available at http://www.biolbull.org/. This article may be cited as: Young, C. M., & George, S. B. (2000). Larval development of the tropical deep‐sea echinoid Aspidodiadema jacobyi: phylogenetic implications. The Biological Bulletin, 198(3), 387‐395. Reference: Biol. Bull. 198: 387-395. (June 2000) Larval Development of the Tropical Deep-Sea Echinoid Aspidodiademajacobyi: Phylogenetic Implications CRAIG M. YOUNG* AND SOPHIE B. GEORGEt Division of Marine Science, Harbor Branch Oceanographic Institution, 5600 U.S. Hwy. 1 N., Ft. Pierce, Florida 34946 Abstract. The complete larval development of an echi- Introduction noid in the family Aspidodiadematidaeis described for the first time from in vitro cultures of Aspidodiademajacobyi, Larval developmental mode has been inferredfrom egg a bathyal species from the Bahamian Slope. Over a period size for a large numberof echinodermspecies from the deep of 5 months, embryos grew from small (98-,um) eggs to sea, but only a few of these have been culturedinto the early very large (3071-pum)and complex planktotrophicechino- larval stages (Prouho, 1888; Mortensen, 1921; Young and pluteus larvae. The fully developed larva has five pairs of Cameron, 1989; Young et al., 1989), and no complete red-pigmented arms (preoral, anterolateral,postoral, pos- ontogenetic sequence of larval development has been pub- lished for invertebrate.One of the terodorsal,and posterolateral);fenestrated triangular plates any deep-sea species whose have been described et at the bases of fenestratedpostoral and posterodorsalarms; early stages (Young al., 1989) is a small-bodied sea urchin with a complex dorsal arch; posterodorsalvibratile lobes; a ring Aspidodiademajacobyi, flexible that lives at in the of cilia around the region of the preoral and anterolateral long spines bathyal depths eastern Atlantic 1).
    [Show full text]
  • The Geological and Biological Environment of the Bear Gulch Limestone (Mississippian of Montana, USA) and a Model for Its Deposition
    The geological and biological environment of the Bear Gulch Limestone (Mississippian of Montana, USA) and a model for its deposition Eileen D. GROGAN Biology Department, St. Joseph’s University, Philadelphia Pa 19131 (USA) Research Associate, The Academy of Natural Sciences in Philadelphia (USA) [email protected] Richard LUND Research Associate, Section of Vertebrate Fossils, Carnegie Museum of Natural History (USA) Grogan E. D. & Lund R. 2002. — The geological and biological environment of the Bear Gulch Limestone (Mississippian of Montana, USA) and a model for its deposition. Geodiversitas 24 (2) : 295-315. ABSTRACT The Bear Gulch Limestone (Heath Formation, Big Snowy Group, Fergus County, Montana, USA) is a Serpukhovian (upper Mississippian, Namurian E2b) Konservat lagerstätte, deposited in the Central Montana Trough, at about 12° North latitude. It contains fossils from a productive Paleozoic marine bay including a diverse biota of fishes, invertebrates, and algae. We describe several new biofacies: an Arborispongia-productid, a filamentous algal and a shallow facies. The previously named central basin facies and upper- most zone are redefined. We address the issue of fossil preservation, superbly detailed for some of the fish and soft-bodied invertebrates, which cannot be accounted for by persistent anoxic bottom conditions. Select features of the fossils implicate environmental conditions causing simultaneous asphyxiation and burial of organisms. The organic-rich sediments throughout the central basin facies are rhythmically alternating microturbidites. Our analyses suggest that these microturbidites were principally generated during summer mon- soonal storms by carrying sheetwash-eroded and/or resuspended sediments over a pycnocline. The cascading organic-charged sediments of the detached turbidity flows would absorb oxygen as they descended, thereby suffocating and burying animals situated below the pycnocline.
    [Show full text]
  • Benton, M.J. and Simms, M.J. 1995. Testing the Marine and Continental
    Downloaded from geology.gsapubs.org on 18 January 2009 Geology Testing the marine and continental fossil records M. J. Benton and M. J. Simms Geology 1995;23;601-604 doi:10.1130/0091-7613(1995)023<0601:TTMACF>2.3.CO;2 Email alerting services click www.gsapubs.org/cgi/alerts to recieve free email alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/index.ac.dtl to subscribe to Geology Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Notes © 1995 Geological Society of America Testing the marine and continental fossil records M. J. Benton Department of Geology, University of Bristol, Bristol BS8 1RJ, United Kingdom M.
    [Show full text]
  • Download This PDF File
    Acta Geologica Polonica, Vol. 53 (2003), No. 2, pp. 143-165 A monograph of the Polish Oxfordian echinoids; Part 1, Subclass Cidaroidea CLAUS, 1880 URSZULA RADWA¡SKA Institute of Geology, University of Warsaw, Al. ˚wirki i Wigury 93; PL-02-089 Warszawa, Poland. E-mail: [email protected] ABSTRACT: RADWA¡SKA, U. 2003. A monograph of the Polish Oxfordian echinoids; Part 1, Subclass Cidaroidea CLAUS, 1880. Acta Geologica Polonica, 53 (2), 143-165. Warszawa. Cidaroid echinoids (subclass Cidaroidea CLAUS, 1880) from the Oxfordian part of a more than 1 km thick Upper Jurassic carbonate sequence developed over epicontinental areas of Poland (Polish Jura, Holy Cross Mountains, Mid-Polish Anticlinorium) are assigned to 13 taxa of the genera Rhabdocidaris DESOR, 1855, Polycidaris QUENSTEDT, 1858, Plegiocidaris POMEL, 1883, and Paracidaris POMEL, 1883. Their taxonomy is revised and discussed with a spe- cial emphasis on establishing the relationships between species based on bare tests and isolated spines. As former attempts to combine these elements, and to accommodate them into particular genera, have resulted in a very con- fused taxonomy of almost all of the species studied, the synonymies of the Polish species are revised. This offers a new insight into content of the genus Paracidaris POMEL, 1883, to which the species Paracidaris blumenbachi (MÜNSTER in GOLDFUSS, 1826), P. elegans (MÜNSTER in GOLDFUSS, 1826), P. florigemma (PHILLIPS, 1829), P. laeviscu- la (L. AGASSIZ, 1840), P. propinqua (MÜNSTER in GOLDFUSS, 1826) are assigned, and whose relation to the often-con- fused species Paracidaris parandieri (L. AGASSIZ, 1840) and P. filograna (L. AGASSIZ, 1840) is discussed.
    [Show full text]
  • Fossils Provide Better Estimates of Ancestral Body Size Than Do Extant
    Acta Zoologica (Stockholm) 90 (Suppl. 1): 357–384 (January 2009) doi: 10.1111/j.1463-6395.2008.00364.x FossilsBlackwell Publishing Ltd provide better estimates of ancestral body size than do extant taxa in fishes James S. Albert,1 Derek M. Johnson1 and Jason H. Knouft2 Abstract 1Department of Biology, University of Albert, J.S., Johnson, D.M. and Knouft, J.H. 2009. Fossils provide better Louisiana at Lafayette, Lafayette, LA estimates of ancestral body size than do extant taxa in fishes. — Acta Zoologica 2 70504-2451, USA; Department of (Stockholm) 90 (Suppl. 1): 357–384 Biology, Saint Louis University, St. Louis, MO, USA The use of fossils in studies of character evolution is an active area of research. Characters from fossils have been viewed as less informative or more subjective Keywords: than comparable information from extant taxa. However, fossils are often the continuous trait evolution, character state only known representatives of many higher taxa, including some of the earliest optimization, morphological diversification, forms, and have been important in determining character polarity and filling vertebrate taphonomy morphological gaps. Here we evaluate the influence of fossils on the interpretation of character evolution by comparing estimates of ancestral body Accepted for publication: 22 July 2008 size in fishes (non-tetrapod craniates) from two large and previously unpublished datasets; a palaeontological dataset representing all principal clades from throughout the Phanerozoic, and a macroecological dataset for all 515 families of living (Recent) fishes. Ancestral size was estimated from phylogenetically based (i.e. parsimony) optimization methods. Ancestral size estimates obtained from analysis of extant fish families are five to eight times larger than estimates using fossil members of the same higher taxa.
    [Show full text]
  • The Complete Devewpment of the Deep-Sea Cidaroid Urchin
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Oregon Scholars' Bank THE COMPLETE DEVEWPMENT OF THE DEEP-SEA CIDAROID URCHIN CIDARIS BLAKEI (AGASSIZ, 1878) WITH AN EMPHASIS ON THE HYALINE LAYER by KATHLEEN BENNETT A THESIS Presented to the Department ofBiology and the Graduate School ofthe University ofOregon in partial fulfillment ofthe requirements for the degree of Master ofScience December 2009 11 "The Complete Development ofthe Deep-Sea Cidaroid Urchin Cidaris blakei (Agassiz, 1878) With an Emphasis on the Hyaline Layer," a thesis prepared by Kathleen Bennett in partial fulfillment ofthe requirements for the Master ofScience degree in the Department ofBiology. This thesis has been approved and accepted by: Al 'Sb1ilAld;, C air ofthe Examining Committee Date Committee in Charge: Alan Shanks, Chair Richard Emlet Craig Young Accepted by: Dean ofthe Graduate School III © 2009 Kathleen Bennett IV An Abstract ofthe Thesis of Kathleen Bennett for the degree of Master ofScience in the Department ofBiology to be taken December 2009 Title: THE COMPLETE DEVELOPMENT OF THE DEEP-SEA CIDAROID URCHIN CIDARIS BLAKEI(AGASSIZ, 1878) WITH AN EMPHASIS ON THE HYALINE LAYER Approved: Alan Shanks Living echinoids comprise two major sister clades, the Euechinoidea and the Cidaroidea. Cidaroids first appeared during the lower Permian (~255 mya) and are considered to represent the primitive form ofall other living echinoids. The present study ofCidaris blakei, a deep-sea planktotrophic cidaroid urchin, provides a description ofdevelopment from fertilization through early juvenile stages and is the first report ofa deep-sea organism reared through metamorphosis.
    [Show full text]
  • Echinodermata: Echinoidea) Alexander Ziegler*1, Cornelius Faber2 and Thomas Bartolomaeus3
    Frontiers in Zoology BioMed Central Research Open Access Comparative morphology of the axial complex and interdependence of internal organ systems in sea urchins (Echinodermata: Echinoidea) Alexander Ziegler*1, Cornelius Faber2 and Thomas Bartolomaeus3 Address: 1Institut für Immungenetik, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Thielallee 73, 14195 Berlin, Germany, 2Institut für Klinische Radiologie, Universitätsklinikum Münster, Westfälische Wilhelms-Universität Münster, Waldeyerstraße 1, 48149 Münster, Germany and 3Institut für Evolutionsbiologie und Zooökologie, Rheinische Friedrich-Wilhelms-Universität Bonn, An der Immenburg 1, 53121 Bonn, Germany Email: Alexander Ziegler* - [email protected]; Cornelius Faber - [email protected]; Thomas Bartolomaeus - [email protected] * Corresponding author Published: 9 June 2009 Received: 4 December 2008 Accepted: 9 June 2009 Frontiers in Zoology 2009, 6:10 doi:10.1186/1742-9994-6-10 This article is available from: http://www.frontiersinzoology.com/content/6/1/10 © 2009 Ziegler et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: The axial complex of echinoderms (Echinodermata) is composed of various primary and secondary body cavities that interact with each other. In sea urchins (Echinoidea), structural differences of the axial complex in "regular" and irregular species have been observed, but the reasons underlying these differences are not fully understood. In addition, a better knowledge of axial complex diversity could not only be useful for phylogenetic inferences, but improve also an understanding of the function of this enigmatic structure.
    [Show full text]