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Getting There: Evidence-Based Decision-Making in Road Trauma Prehospital Transport and Care in Queensland
- Robert Andrews, Moe Wynn, Arthur ter Hofstede, Kirsten Vallmuur, Emma Bosley, Mark Elcock, Stephen Rashford
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- Journal:
- Prehospital and Disaster Medicine / Volume 34 / Issue s1 / May 2019
- Published online by Cambridge University Press:
- 06 May 2019, pp. s64-s65
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- May 2019
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Introduction:
Process mining, a branch of data science, aims at deriving an understanding of process behaviors from data collected during executions of the process. In this study, we apply process mining techniques to examine retrieval and transport of road trauma patients in Queensland. Specifically, we use multiple datasets collected from ground and air ambulance, emergency department, and hospital admissions to investigate the various patient pathways and transport modalities from accident to definitive care.
Aim:The project aims to answer the question, “Are we providing the right level of care to patients?” We focus on (i) automatically discovering, from historical records, the different care and transport processes, and (ii) identifying and quantifying factors influencing deviance from standard processes, e.g. mechanisms of injury and geospatial (crash and trauma facility) considerations.
Methods:We adapted the Cross-Industry Standard Process for Data Mining methodology to Queensland Ambulance Service, Retrieval Services Queensland (aero-medical), and Queensland Health (emergency department and hospital admissions) data. Data linkage and “case” definition emerged as particular challenges. We developed detailed data models, conduct a data quality assessment, and preliminary process mining analyses.
Results:Preliminary results only with full results are presented at the conference. A collection of process models, which revealed multiple transport pathways, were automatically discovered from pilot data. Conformance checking showed some variations from expected processing. Systematic analysis of data quality allowed us to distinguish between systemic and occasional quality issues, and anticipate and explain certain observable features in process mining analyses. Results will be validated with domain experts to ensure insights are accurate and actionable.
Discussion:Preliminary analysis unearthed challenging data quality issues that impact the use of historical retrieval data for secondary analysis. The automatically discovered process models will facilitate comparison of actual behavior with existing guidelines.
Primitive stalked echinoderms from the Middle Ordovician (Darriwilian) of Bang Song Tho, Kanchanaburi, western Thailand
- CHRISTOPHER R.C. PAUL, ARTHUR J. BOUCOT, STEPHEN K. DONOVAN, REN-BIN ZHAN, WATTANA TANSATHIEN
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- Journal:
- Geological Magazine / Volume 156 / Issue 1 / January 2019
- Published online by Cambridge University Press:
- 30 October 2017, pp. 147-171
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The Middle Ordovician (Darriwilian) echinoderm fauna of Bang Mueang Song Tho, western Thailand (Pha Phum group, Bo Ngam Formation(?)), includes rare thecae, and common thecal ossicles and columnals, and is dominated by ‘cystoids’. Cheirocrinid glyptocystitoids include Cheirocystella sp. (= Echinoencrinites sp. aff. E. senckenbergii (von Meyer) sensu Wolfart), ‘Cheirocrinus’ sp. and Cheirocrinidae incertae sedis. Hemicosmitoids are composed of Paracaryocrinites kochi (Wolfart), ‘Paracaryocrinites’ sp. and Polycosmites sp. cf. P. kaekeli Wolfart. The aristocystitid Sinocystis sp. cf. S. loczyi Reed is the only diploporite. Columnals of Bystrowicrinus (col.) sp. are probably crinoidal. The fullest determination of the echinoderm biodiversity of this site has been obtained using all specimens from single ossicles to articulated thecae. The limited taphonomic data suggests that the echinoderm assemblage is parauthochthonous. Other echinoderms described from coeval deposits in this region include Stichocystis thailandica Wolfart; Heliocrinites sp. aff. H. qualus Bather (probably a Lophotocystis Paul); Gomphocystites? sp. indet. (= trilobite?); Codiacystis sp. aff. C. bohemicus (Barrande) (= bryozoan?); Aristocystis [sic] sp. A of Paul; and [non] Incertae sedis sp. C of Paul (may not be an echinoderm).
Chronology and provenance of last-glacial (peoria) loess in western iowa and paleoclimatic implications
- Daniel R. Muhs, E. Arthur Bettis III, Helen M. Roberts, Stephen S. Harlan, James B. Paces, Richard L. Reynolds
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- Quaternary Research / Volume 80 / Issue 3 / November 2013
- Published online by Cambridge University Press:
- 20 January 2017, pp. 468-481
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Geologic archives show that the Earth was dustier during the last glacial period. One model suggests that increased gustiness (stronger, more frequent winds) enhanced dustiness. We tested this at Loveland, Iowa, one of the thickest deposits of last-glacial-age (Peoria) loess in the world. Based on K/Rb and Ba/Rb, loess was derived not only from glaciogenic sources of the Missouri River, but also distal loess from non-glacial sources in Nebraska. Optically stimulated luminescence (OSL) ages provide the first detailed chronology of Peoria Loess at Loveland. Deposition began after ~ 27 ka and continued until ~ 17 ka. OSL ages also indicate that mass accumulation rates (MARs) of loess were not constant. MARs were highest and grain size was coarsest during the time of middle Peoria Loess accretion, ~ 23 ka, when ~ 10 m of loess accumulated in no more than ~ 2000 yr and possibly much less. The timing of coarsest grain size and highest MAR, indicating strongest winds, coincides with a summer-insolation minimum at high latitudes in North America and the maximum southward extent of the Laurentide ice sheet. These observations suggest that increased dustiness during the last glacial period was driven largely by enhanced gustiness, forced by a steepened meridional temperature gradient.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- The Cambridge Dictionary of Philosophy
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- 05 August 2015
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- 27 April 2015, pp ix-xxx
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- By Brittany L. Anderson-Montoya, Heather R. Bailey, Carryl L. Baldwin, Daphne Bavelier, Jameson D. Beach, Jeffrey S. Bedwell, Kevin B. Bennett, Richard A. Block, Deborah A. Boehm-Davis, Corey J. Bohil, David B. Boles, Avinoam Borowsky, Jessica Bramlett, Allison A. Brennan, J. Christopher Brill, Matthew S. Cain, Meredith Carroll, Roberto Champney, Kait Clark, Nancy J. Cooke, Lori M. Curtindale, Clare Davies, Patricia R. DeLucia, Andrew E. Deptula, Michael B. Dillard, Colin D. Drury, Christopher Edman, James T. Enns, Sara Irina Fabrikant, Victor S. Finomore, Arthur D. Fisk, John M. Flach, Matthew E. Funke, Andre Garcia, Adam Gazzaley, Douglas J. Gillan, Rebecca A. Grier, Simen Hagen, Kelly Hale, Diane F. Halpern, Peter A. Hancock, Deborah L. Harm, Mary Hegarty, Laurie M. Heller, Nicole D. Helton, William S. Helton, Robert R. Hoffman, Jerred Holt, Xiaogang Hu, Richard J. Jagacinski, Keith S. Jones, Astrid M. L. Kappers, Simon Kemp, Robert C. Kennedy, Robert S. Kennedy, Alan Kingstone, Ioana Koglbauer, Norman E. Lane, Robert D. Latzman, Cynthia Laurie-Rose, Patricia Lee, Richard Lowe, Valerie Lugo, Poornima Madhavan, Leonard S. Mark, Gerald Matthews, Jyoti Mishra, Stephen R. Mitroff, Tracy L. Mitzner, Alexander M. Morison, Taylor Murphy, Takamichi Nakamoto, John G. Neuhoff, Karl M. Newell, Tal Oron-Gilad, Raja Parasuraman, Tiffany A. Pempek, Robert W. Proctor, Katie A. Ragsdale, Anil K. Raj, Millard F. Reschke, Evan F. Risko, Matthew Rizzo, Wendy A. Rogers, Jesse Q. Sargent, Mark W. Scerbo, Natasha B. Schwartz, F. Jacob Seagull, Cory-Ann Smarr, L. James Smart, Kay Stanney, James Staszewski, Clayton L. Stephenson, Mary E. Stuart, Breanna E. Studenka, Joel Suss, Leedjia Svec, James L. Szalma, James Tanaka, James Thompson, Wouter M. Bergmann Tiest, Lauren A. Vassiliades, Michael A. Vidulich, Paul Ward, Joel S. Warm, David A. Washburn, Christopher D. Wickens, Scott J. Wood, David D. Woods, Motonori Yamaguchi, Lin Ye, Jeffrey M. Zacks
- Edited by Robert R. Hoffman, Peter A. Hancock, University of Central Florida, Mark W. Scerbo, Old Dominion University, Virginia, Raja Parasuraman, George Mason University, Virginia, James L. Szalma, University of Central Florida
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- The Cambridge Handbook of Applied Perception Research
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- 05 July 2015
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- 26 January 2015, pp xi-xiv
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- By James P. Bednarz, William C. Carroll, Francis X. Connor, Trevor Cook, Gabriel Egan, Julia Griffin, Brean Hammond, Rui Carvalho Homem, Sujata Iyengar, Russell Jackson, Isabel Karremann, Arthur F. Kinney, Tina Krontiris, Barry Langston, Stephan Laqué, Dennis McCarthy, Ellen MacKay, Roderick H. McKeown, Sonia Massai, L. Monique Pittman, James Purkis, Carol Chillington Rutter, June Schlueter, Charlotte Scott, Will Sharpe, James Shaw, Simon Smith, B. J. Sokol, Stephen Spiess, Gary Taylor, Leslie Thomson, Sir Brian Vickers, William W. Weber
- Edited by Peter Holland, University of Notre Dame, Indiana
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- Shakespeare Survey
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- 05 October 2014
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- 02 October 2014, pp vi-vi
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4 - The Cambrian explosion
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp 35-44
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Summary
As we saw in Chapter 2, there have been multicellular life-forms on this planet since about 1200 million years ago (MYA). These first life-forms, however, were not animals; they were probably red algae. Later, in the Ediacaran period, which began some 635 MYA, there are fossils of multicellular creatures, some of which may have been animals; their interpretation remains controversial. The beginning of the Cambrian period, 542 MYA, marks the start of an abundant fossil record of creatures that undoubtedly are animals. In the Cambrian we are faced with a profusion of animal fossils, both those that we recognize as being clearly related to some of today’s animals, and others that are more enigmatic in terms of where to place them in our ‘groups within groups’ system of naming and ordering animals that we inherited from Linnaeus.
Geological periods are often named after places where rocks of the relevant age are found. As we noted in Chapter 2, the Ediacaran period is named after the Ediacara Hills in Australia. The Cambrian is named after Wales. The basis of this latter naming is not as readily apparent as that of the former. But the Welsh name for Wales – Cymru – gets us a bit closer to seeing the connection. And the Roman name – Cambria – makes it crystal clear. There is even a town in Wales where the local newspaper is called The Cambrian News.
Dedication
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp v-vi
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Index
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp 329-335
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17 - Comparing embryos
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp 166-176
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Summary
When first examining animal development in Chapter 13, we noted that a pioneer of the subject of embryology was the Italian Hieronymus Fabricius, whose studies on the development of the chick were published posthumously in 1621. This work can best be considered as descriptive embryology – it involved a focus on a particular animal and gave as detailed a description of its embryogenesis as the techniques of the time would allow.
It was not until about two centuries later that embryology became truly comparative. This aspect of embryology is clearly related to evolution, as was recognized by Darwin, who, in 1859, devoted part of chapter 13 in On the Origin of Species to their relationship. An often-quoted statement that Darwin makes there is: “community in embryonic structure reveals community of descent.” We might do well to examine this statement carefully, to try to come up with a modern version of it, and to see what course of logic such an attempt will set in train.
28 - Animal extremophiles
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp 285-294
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Summary
Although the subject matter of this chapter is very different from that of the last one and the next one, a common theme running through all three is probability, or perhaps – though it’s really the same thing looked at from a different perspective – improbability. In the last chapter we saw that the nature of the developmental system made the evolution of certain kinds of animal improbable. In the next chapter we look at the probability of animal-type life on other planets. Here, we look at animals called extremophiles that live in parts of our own planet where animal life would at first sight seem improbable, and/or that have tolerance of extreme conditions.
Although these animals are indeed called extremophiles, this term is used also to describe other forms of life, from other kingdoms, that can withstand extreme environments. So the term can be used also for plants and fungi, and especially for organisms from the bacterial and archaean domains, where an extremophile existence is most commonly found. But here we’ll concentrate on extremophile animals. We’ll also concentrate on extremes of temperature; but it’s worth noting that extremophile can be used in relation to other environmental variables – for example acidity.
13 - How to make an animal
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp 123-134
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Summary
Every animal gets made by two processes, which take very different lengths of time. The longer-term process is the one we’ve already been discussing in most chapters of the book: evolution. Here, a particular type of animal is made from a different, earlier-arising type by a series of modifications that rely on Darwinian natural selection and perhaps, as we’ll see later, on other things. The shorter-term process is the one we will now begin to address explicitly: development. Here, an animal is made from the starting point of (usually) a fertilized egg.
Although evolution and development work on very different timescales, they are inextricably linked. Each is, in a manner of speaking, the starting point for the other. To see this clearly, it helps to consider the whole of egg-to-adult development as a trajectory, or, to put it another way, as a route from a simple, unicellular beginning to a complex, multicellular end. Each type of animal has such a trajectory, though when animals with very different adult forms are compared, their developmental trajectories are found to be likewise very different (especially in their later stages). For example, although we have not looked at any developmental details yet, it is clear, to use the molluscs of the last chapter as an example, that a very different route must be taken from the fertilized egg to end up in one case with a snail and in another case with an octopus.
11 - Trends in animal complexity
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp 104-112
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Summary
A pervasive theme that has been with us since the beginning of the book – sometimes explicitly, other times implicitly – is that more complex animals are not necessarily more ecologically successful than simple ones. Indeed, this theme first emerged (Chapter 1) in a broader context than the animal kingdom – the context of life in general. The very first life-forms on Earth were probably rather like today’s bacteria. The fact that bacteria and other unicellular forms continue to prosper attests to the fact that you don’t have to be a big, complex organism to be fit – in the evolutionary sense of the word, as explained in Chapter 5. This point was reinforced in the previous chapter when we noted the incredible ecological success of roundworms, most of the 25,000 species of which are small and, in structural terms, quite simple, compared, for example, to arthropods or vertebrates.
It was this point (among others) that led me to state, at an early stage in the book, that evolution is not an escalator, up which creatures go at varying rates to higher levels of complexity. Some evolutionary lineages have shown rises in complexity over geological time, but others have not. Some have even shown decreases in complexity.
8 - The enigmatic urbilaterian
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 05 August 2014
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- 07 August 2014, pp 77-84
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Summary
Evolutionary trees, such as those we looked at in the last chapter, are very abstract things. They take a complex process involving many animals, molecules, morphological characters, matings, migrations, speciation events and geography, and render this multi-level, four-dimensional complexity into a simple-looking picture on a single sheet of paper. For some purposes that’s great. After all, when we are trying to understand a complex process, any device that captures the essence of the process in a simple diagrammatic way is incredibly helpful. But it can also be misleading; and whether it does indeed capture ‘the essence of the process’ can be questioned. I think this is especially true in relation to the extinct animal that has come to be called the urbilaterian (and nicknamed, somewhat tongue-in-cheek, ‘Urbi’).
What was this strangely named beast? Answers to this question can come in a variety of forms. In terms of the name, it uses the German prefix ur-, meaning first or original, and couples that with bilaterian, which is short for ‘bilaterally symmetrical animal’. As we saw in previous chapters, the most basally branching animals either had little or no symmetry (sponges) or had radial symmetry (jellyfish and their kin). But most other animals that we see around us are bilaterally symmetrical, albeit with various degrees of imperfection. Therefore, at some point in the distant past, bilateral symmetry must have originated, and the first animal displaying it was the urbilaterian.
5 - How to make a species
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Book:
- Evolving Animals
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- 07 August 2014, pp 45-55
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Summary
Charles Darwin’s On the Origin of Species, published in 1859, can rightly be regarded as the start of evolutionary biology. That’s not to say that it was the first publication on evolution, but it was the first to convince most scientists – in some cases immediately and in others eventually – that (a) evolution had happened and (b) it occurred via a particular mechanism, namely natural selection, or ‘survival of the fittest’.
In the previous chapter we saw that, whatever uncertainties remain about the origin of animals, by 500 million years ago the Cambrian oceans were teeming with animal life. They were doubtless teeming with bacterial and algal life too, though the flowering plants that dominate the plant kingdom today did not evolve until much later. In the Cambrian, all multicellular life-forms were aquatic – the land did not get colonized by plants and animals for probably another 100 million years.
Because natural selection is a general mechanism of evolutionary change, it must have been operating in those ancient marine ecosystems of the Cambrian much as it operated in their more recent terrestrial equivalents over the last six or seven million years to modify human and chimp lineages from their last common ancestor. And indeed it is still operating in the same way today, as we see in the evolution of biocide-resistant insects and bacteria.
3 - How to make a fossil
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 07 August 2014, pp 25-34
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Consider a typical garden somewhere in Ireland – or, for that matter, in Britain, France or Massachusetts. Regardless of its exact size, many animals will die there on a daily basis. Most will leave no trace of their existence; within a few days or weeks it will be as if they had never lived. Far from becoming fossils for palaeontologists of the distant future to inspect and interpret, they will leave no clues as to their structure, function, or ecological context.
A good example is the death of an earthworm when a blackbird pecks it out of the top layer of the soil and eats it whole. Not only will the worm’s flesh be completely digested in the alimentary canal of the bird, but earthworms have no hard parts – no teeth, shell or bones – to be egested by the bird and left on the ground for possible fossilization.
10 - A plethora of worms
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 07 August 2014, pp 94-103
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In the introductory chapter, we looked at the structure of the animal kingdom in terms of the relative numbers of species belonging to different groups. There, we concentrated in particular on the relative numbers of vertebrate and invertebrate species; and we saw that vertebrates make up less than 5% of the animal kingdom. Here, we pursue the theme of the make-up of the animal kingdom further, but from a different perspective: not the proportion of it that is vertebrate but the proportion that is vermiform – or worm-like.
However, this issue is not as simple as it seems. There are many different ways of assessing the size of any particular group of animals. Also, as we have seen already, there are many different ways of defining ‘group’, especially in the light of Darwin’s ‘groups within groups’ picture, for which he gave a mechanistic explanation – evolution. Prior to Darwin, the groups-within-groups view had probably been held by all serious students of zoology, and had been formalized by the Swede Carl Linnaeus – for plants as well as animals – way back in 1735.
25 - Animal plasticity
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 07 August 2014, pp 251-261
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We can generalize the point made in the last chapter about the role of environmental factors in determining human height to the role of these factors in determining the body sizes of most if not all animals. Indeed, we can generalize further, because environmental factors play a role in determining the values of many characters in most or all animals, including those that are unrelated to size. In other words, the genes do not completely determine the course of development; rather, this course is set by a mixture of genetic and environmental influences, and the interactions between them.
There are several ways of describing the effects of environmental factors on development. One way is to say that a character such as body size upon whose value there is an environmental influence has only a partial heritability. Another is to say that there is an element of plasticity in the character concerned. More complete terms for the latter are phenotypic plasticity or developmental plasticity, the second term being preferable for reasons already given in Chapter 22.
27 - The direction of evolution
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 07 August 2014, pp 274-284
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The great American palaeontologist G. G. Simpson, in discussing Darwinian and other evolutionary theories, made the following point in 1953: “The various major schools of evolutionary theory have arisen mainly from differences of opinion as to how evolution is oriented.” Of course, in the Darwinian school, natural selection is seen as the main cause of evolutionary orientation, or direction. In other words, this school of thought has it that natural selection steers evolution and thus causes particular lineages to go in one direction, say increasing body size, rather than another. This differs from the earlier Lamarckian approach, which involved the inheritance of acquired characters – now known not to occur – in the determination of evolutionary direction.
Natural selection is a systematic rather than random process. But its raw material is variation, and this derives ultimately from genetic mutation, which is often said to be random. However, this latter point needs some elucidation. A key assumption of Darwinian theory – sometimes explicit, sometimes implicit – is that the variation upon which natural selection acts is random with respect to whatever would be favoured under the prevailing environmental conditions. In other words, the variation is considered not to be biased in favour of forms that would have increased fitness. This is generally believed to be correct.
22 - Variation and inheritance
- Wallace Arthur, National University of Ireland, Galway
- Illustrated by Stephen Arthur
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- Evolving Animals
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- 07 August 2014, pp 222-231
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The existence of variation is a prerequisite for natural selection to be able to work. Furthermore, the variation must be at least partly heritable, because if it is not then any differences between variants in their survival rate or their number of offspring will not be carried through to the next generation and subsequent ones. Darwin made the importance of variation very clear in the way he structured On the Origin of Species: the first chapter is called “Variation under domestication” and the second “Variation under nature”. Thus, to get to his main contribution to evolutionary theory, he took a route that started with variation. (“Natural selection” is his fourth chapter).
Not only must variation be heritable, but the mechanism of inheritance must work in such a way as to maintain it. This may seem a strange point to us now, in the twenty-first century, but Darwin was acutely aware of the problem that if inheritance worked by some kind of blending of the contributions of the two parents, then in just a few generations whatever variation there was would have been eliminated. And at the time when Darwin was writing his magnum opus, the idea of blending inheritance was commonplace; it was not until some years later, in 1866, that a different mechanism of inheritance was proposed by the Austrian monk Gregor Mendel. Even then, this different mechanism, which is referred to as particulate rather than blending inheritance, languished in obscurity until its rediscovery in 1900.