Facts on file dictionary of evolutionary biology

The Facts On File DICTIONARY of EVOLUTIONARY BIOLOGY The Facts On File DICTIONARY of EVOLUTIONARY BIOLOGY Edited by Elizabeth Owen Eve Daintith ® The Facts On File Dictionary of Evolutionary Biology Copyright © 2004 by Market House Books Ltd All rights reserved No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher For information contact: Facts On File, Inc 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data The Facts on File dictionary of evolutionary biology / edited by Elizabeth Owen and Eve Daintith p cm Includes bibliographical references ISBN 0-8160-4924-6 (alk paper) Chemistry—Dictionaries I Title: Dictionary of evolutionary biology II Owen, Elizabeth III Daintith, Eve XXXXXXXXX XXXXXXXXX XXXXXXXXXX Facts On File books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755 You can find Facts On File on the World Wide Web at http://www.factsonfile.com Compiled and typeset by Market House Books Ltd, Aylesbury, UK Printed in the United States of America MP 10 This book is printed on acid-free paper CONTENTS Preface vii Entries A to Z Appendixes I The Animal Kingdom 245 II The Plant Kingdom 246 III Webpages Bibliography 247 248 PREFACE This dictionary is one of a series covering the terminology and concepts used in important branches of science The Facts on File Dictionary of Evolutionary Biology is planned as an additional source of information for students taking Advanced Placement (AP) Science courses in high schools It will also be helpful to older students taking introductory college courses This volume covers the topics important for an understanding of evolutionary theory, including classification, paleontology, genetics, molecular biology, and some geology The definitions are intended to be clear and informative and, where possible, we have provided helpful diagrams and examples The book also has a selection of short biographical entries for people who have made important contributions to the field There are appendixes showing the classification of animals and plants We have also added a short list of useful webpages and an informative bibliography The book will be a helpful additional source of information for anyone studying the AP Biology course, especially the sections of the course covering Heredity and Evolution However, we have not restricted the content to this syllabus Evolutionary theory is an important, and sometimes controversial, area of modern science and we have tried to cover it in an interesting and informative way ACKNOWLEDGMENTS Consultant editor Robert Hine B.Sc vii A A See adenine; genotypic effect e.g heat shock proteins, that help the organism cope and thereafter these proteins are only expressed when the stress is encountered Expressing such proteins all the time would be a drain on resources so it is an advantage to be able to express them only when they are needed ABC floral model In evolutionary development, a theory describing the that bring about the arrangement of parts of a flower in whorls (circles) rather than along an axis Working on Arabidopsis (a small annual plant of the Brassicaceae (mustard) family) it has been discovered that three classes of genes are involved, denoted A, B, and C A genes alone are responsible for the outer whorl of leaflike sepals; A and B genes together regulate the development of the next whorl of petals; B and C genes control the development of the stamens; C genes alone determine the development of the inner whorl of carpels What is most significant is that the gene leafy – a ‘higher control’ gene – regulates the ABC system showing that the flower parts are based on a leaf archetype or basic plan See also recapitulation HOMEOTIC GENES acentric Denoting a chromosome or fragment of a chromosome that lacks a centromere Acheulian tools Stone Age tools, especially hand axes They have been excavated along with early hominid remains, for example, those of Homo erectus at Olduvai Gorge in East Africa and also with Homo ergaster The use of these tools in human evolution is not thought to be as important as it once was as it has been discovered that chimpanzees have also used tools extensively See also Oldowan industrial complex; Mousterian tools; Upper Paleolithic tools abiogenesis The development of living from nonliving matter, as in the ORIGIN OF acoelomate An LIFE Acanthocephala See Rotifera animal without a i.e there is no cavity between the digestive tract and the body wall Examples are the PLATYHELMINTHES and the nemertines (ribbon worms) Acasta rocks The oldest rocks known, acorn worm See Hemichordata COELOM, absolute dating See dating techniques dated at just over 4000 million years old, found in NW Canada See Earth, age of acquired characteristic (acquired trait) A phenotypic change in the structure or function of an organ or system during the life of an organism, brought about by the use or disuse of that organ or system or by environmental influences Most are the result of disease, injury, starvation, or senescence Acquired characteristics are not genetically based and cannot be inherited acclimatization A method by which organisms adapt and survive temporary, but recurring, stressful environments in which prior exposure to a particular stress leads to the organism being better able to cope the next time it is encountered The first exposure results in the expression of proteins, VNTR VNTR See genetic fingerprinting ground water coming into contact with hot molten magma beneath the surface volcano A vent or fissure on the Earth’s surface connected by a conduit to the Earth’s interior, from which MAGMA (which becomes lava), gas, dust, and fine particles are erupted Igneous rocks, e.g basalt, are formed as a result of volcanic action Hot water and steam can also escape through vents and are produced by Von Baer’s law The early developmental stages of a group of related species are more similar than the later stages because ancestral characters appear earlier in development than derived characters vulpavine See Carnivora; Oligocene 234 W Waddington, Conrad Hal (1905–75) British embryologist and geneticist As a geneticist and a Darwinian, Waddington introduced two important concepts into the discussion of evolutionary theory The first dealt with developmental reactions that occur in organisms exposed to natural selection and proposed that such reactions are generally canalized In other words, they adjust to bring about one definite end result notwithstanding small changes in conditions over the course of the reaction The second idea was introduced in his 1953 paper Genetic Assimilation of an Acquired Character, in which he tried to show that the inheritance of acquired characteristics, the ‘heresy’ of Jean LAMARCK, could in fact be incorporated into orthodox genetics and evolutionary theory (see genetic assimilation) As an example Waddington quoted the calluses formed on the embryonic rump of an ostrich If the Lamarckian explanation of the inheritance of an earlier acquired characteristic is rejected then what remains is the convenient but implausible appearance of a random mutation Waddington claimed to have demonstrated experimentally the process of genetic assimilation in normal fruit flies (Drosophila) He subjected the pupae of the flies to heat shock and noted that a small proportion developed lacking the posterior cross-vein in their wings Careful breeding increased the proportion of such flies and eventually Waddington built up a stock of flies without cross-veins that had never been subjected to heat shock The experiment has been criticized as dealing with nonadaptive traits It also appears to be the case that other genetic mechanisms are available to explain the data without assuming genetic assimilation wahlund effect The higher proportion of homozygotes found in a divided POPULATION compared with a single population of the same size Wallace, Alfred Russel (1823–1913) British naturalist Wallace received only an elementary schooling before joining an elder brother in the surveying business In 1844 he met the entomologist Henry BATES Wallace persuaded Bates to accompany him on a trip to the Amazon, and they joined a scientific expedition as naturalists in 1848 Wallace published an account of his expedition in his A Narrative of Travels on the Amazon and River Negro (1853) In 1854 he traveled to the Malay Archipelago, where he spent eight years and collected over 125,000 specimens, a journey described in his Malay Archipelago (1869) In this region he noted the marked differences between the Asian and Australian faunas, the former being more advanced than the latter, and proposed a line, still referred to as WALLACE’S LINE, separating the two distinct ecological regions He suggested that Australian animals are more primitive because the Australian continent broke away from Asia before the more advanced Asian animals evolved and thus the marsupials were not overrun and driven to extinction This observation, together with a reconsideration of Thomas MALTHUS’s essay on population, led him to propose the theory of evolution by natural selection He wrote an essay entitled On the Tendency of Varieties to Depart Indefinitely from the Original Type, which he 235 Wallace’s line sent to DARWIN for his opinion On receipt, Darwin realized this was a summary of his own views and the two papers were jointly presented at a meeting of the Linnaean Society in July 1858 Wallace continued to collect evidence for this evolutionary theory, making an important study of mimicry in the swallowtail butterfly and writing pioneering works on the geographical distribution of animals, including his Geographical Distribution of Animals (2 vols., 1876) and Island Life (1880) In addition to his scientific and political pursuits, Wallace also participated in many of the more dubious intellectual movements of the 19th century He supported spiritualism, phrenology, and mesmerism His views on these matters led Wallace to disagree with Darwin on the evolution of humans Man’s spiritual essence, Wallace insisted, could not have been produced by natural selection Darwin commented, “I hope you have not murdered our child.” Wallace’s line A hypothetical boundary in Indonesia between the islands of Bali and Lombok It separates the AUSTRALASIAN and ORIENTAL zoogeographical regions and was drawn by A R WALLACE, co-founder with DARWIN of the theory of evolution warm-blooded See homoiothermy warning coloration (aposematic coloration) A conspicuous coloring or marking by which a noxious or dangerous animal can be recognized by potential attackers Since these animals have developed their foul taste or dangerous nature to protect themselves from predation, it is important for them to warn potential predators of this Warning coloration is common in insects, for example, the bright blackand-yellow stripes of many wasps Venomous snakes often advertise their dangerous nature by their conspicuous markings Weberian ossicles A paired chain of three or four small bones in certain fish (e.g carps and catfishes) that connect the swim bladder with the auditory capsule They are modified from the first four vertebrae and are comparable in function with the EAR OSSICLES in higher vertebrates in that they conduct pressure changes from the swim bladder to the inner ear Weismann, August Friedrich Leopold (1834–1914) German biologist In his early work Weismann made much use of the microscope, but failing eyesight forced him to abandon microscopy for theoretical biology His microscopic observations, especially those on the origin of the germ cells of hydrozoans, were nevertheless put to good use in the formulation of his theory of the continuity of the germ plasm, which he published in 1886 (English translation, 1893; The Germ-Plasm: A Theory of Heredity) Weismann had noted that germ cells can be distinguished from somatic cells early in embryonic development, and from this he visualized the protoplasm of the germ cell (germ plasm) as being passed on unchanged through the generations and therefore responsible for inheritance Although the body might be modified by environmental effects, the germ plasm – well protected within it – could not be This insulation of the germ plasm from environmental influences – the so-called Weismann barrier – is one of the fundamental tenets of modern Darwinian theory (see Darwinism) Weismann himself argued strongly against the Lamarckian theory of the inheritance of acquired characteristics (see Lamarckism) His publication Studies in the Theory of Descent (1882) contained a preface by Darwin Weismann barrier See Weismann Weismannism The ideas put forward by WEISMANN criticizing the theory of the inheritance of acquired bodily characteristics implicit in Lamarckism and certain aspects of Darwinism Weismann synthesized his ideas into the ‘Theory of the Continuity of the Germ Plasm’, which emphasized the distinction between the somatic cells and the germ cells and stated that inheritance was effected only by the germ cells 236 Wright, Sewall whales See Cetacea; missing link whisk ferns See Psilophyta wild type The GENOTYPE or PHENOTYPE that occurs naturally in most members of a species Wilson, Allan Charles (1934–91) New Zealand biochemist In 1967, in collaboration with Vincent SARICH, Wilson argued that MOLECULAR CLOCKS could reveal much about the early history of humans Against the opposition of paleontologists they claimed that the divergence between humans and the great apes began only mya Their view seems to have prevailed In the 1980s Wilson sought to challenge the paleontologists once more, this time on the issue of the emergence of modern humans While anthropologists favored a date of million years, Wilson’s work suggested a time no later than 200 000 years ago He chose to work with mitochondria, the cellular organelles that convert food into energy (see mitochondrion) Like a cell nucleus, mitochondria also contain DNA It encodes, however, only 37 genes as opposed to the 100 000 of nuclear DNA Further, MITOCHONDRIAL DNA evolved rapidly and regularly and, surprisingly, it is inherited from the mother alone It follows, Wilson pointed out, that “all human mitochondrial DNA must have had an ultimate common female ancestor.” Where and when, he went on to ask, could she be found? Wilson adopted the parsimony principle that subjects are connected in the simplest possible way That is, the fewer differences found in mitochondrial DNA, the closer they were connected Mitochondria from 241 individuals from all continents and races were collected and analyzed The tree constructed had two branches, both of which led back to Africa What was the date of this MITOCHONDRIAL EVE? Wilson measured the ratio of mitochondrial DNA divergence between humans to the divergence between humans and chimpanzees The ratio was found to be 1:25 and, because human and chimpanzee lineages diverged mya, human maternal lineages must have separated by 1/25 of this time, namely, 200 000 years ago (see out of Africa theory) Wilson’s hypothesis, first presented in 1987, has provoked considerable opposition Those who prefer a multiregional explanation of human evolution (see multiregional theory) have questioned most of Wilson’s assumptions and have argued that until it is backed up by unequivocal fossil evidence it must remain speculative wings See Aves; Insecta wobble hypothesis The hypothesis that the base pairing of the third base of a tRNA ANTICODON is not specific It is consistent with the degeneracy of the GENETIC CODE Wolffian duct One of a pair of ducts in fish and amphibians that transports urine from the kidney to the cloaca In the male it is a urinogenital duct, also transporting spermatozoa from the testes In reptiles, birds, and mammals, it is functionally replaced by the ureter and persists only in the male, forming the epididymis and vas deferens See also mesonephros World Continent See zoogeography Wright, Sewall (1889–1988) American statistician and geneticist He began his researches into the population genetics of guinea pigs His first work aimed to find the best combination of inbreeding and crossbreeding to improve stock, this having practical application in livestock breeding From this he also developed a mathematical theory of evolution His name is best known in connection with the process of GENETIC DRIFT, the Sewall Wright effect 237 X X chromosome The larger of the two types of SEX CHROMOSOME in mammals and certain other animals It is similar in appearance to the other chromosomes and carries many sex-linked genes See sex determination xenungulates See amblypods xylem The water-conducting tissue in vascular plants It consists of dead hollow cells (tracheids and vessels), which are the conducting elements, together with additional supporting tissue 238 Y Y chromosome The smaller of the two types of SEX CHROMOSOME in mammals and certain other animals It is found only in the heterogametic sex See sex determination Yucatán crater See Alvarez theory 239 Z Zinjanthropus boisei See Paranthropus boisei zircons Crystals of zirconium silicate that trap uranium and can be used in dating some ancient rocks, e.g the ACASTA ROCKS may also be grouped with one another as Arctogea): NEARCTIC (most of North America), PALEARCTIC (Europe, northern Asia, and North Africa), ORIENTAL (southern Asia), and ETHIOPIAN (subSaharan Africa) See also phytogeography; Wallace’s line zoology The scientific study of animals zone fossil (indicator fossil; index fossil) A species that is characteristic of a particular sedimentary rock and restricted to it in time, for example, certain AMMONITES in the Cretaceous zoogeographical region See zoogeog- raphy zoogeography The study of the geographical distribution of animal species Such studies show that the Earth can be divided into distinct zoogeographical regions, each having its own unique collection of animal species For example, the continents of the Southern hemisphere – Australia, subSaharan Africa, and South America – each have a characteristic fauna not found elsewhere Anteaters, sloths, and armadillos are native to South America; marsupial and monotreme mammals are characteristic of Australia; while Africa shows a greater diversity of fauna than any other region The island continents consist of the AUSTRALASIAN region (Australia, New Zealand, and the surrounding islands, and the NEOTROPICAL region (South America) The other regions are grouped into the World Continent (Europe, Asia, Africa, and North America), which have comprised a more or less continuous land mass throughout geological time This group consists of the following four regions (that Zoomastigina A phylum of heterotrophic protoctists that possess one or more undulipodia (flagella) for locomotion It includes both free-living forms (e.g Naegleria) and parasites (e.g Trypanosoma, which is responsible for sleeping sickness), and aerobic and anaerobic forms In some recent classifications this phylum has been disbanded and its members dispersed to other taxa according to whether or not they possess mitochondria zooplankton See plankton zooxanthellae See dinoflagellate Zuckerandl, Emile (1922– ) Austrian molecular evolutionary biologist Zuckerandl has examined the hemoglobin (red blood pigment) from a number of animal species Human hemoglobin is composed of four chains The beta-chain consists of 146 amino acids When compared with the beta-chain of a gorilla it differs at just one point, containing arginine where the gorilla has lysine In contrast horse-beta differs at 26 sites and fish hemoglobin has a total lack of overlap Zuckerandl argued that comparison of hemoglobin chains offered a way to measure the rate at which evolution works Thus variations between the alpha and beta hemoglobin chains of humans with 240 zygotene those of horses, pigs, cattle, and rabbits produced a mean number of differences of 22 If the estimated time of their common ancestor is 80 million years then it can be estimated that there should be a change of one amino acid per seven million years Zuckerandl’s approach has been adapted by other workers Vincent SARICH in 1967 used the protein albumin to establish a MOLECULAR CLOCK and Allan WILSON has used MITOCHONDRIAL DNA zygomorphy See bilateral symmetry dia They are mostly saprophytic, absorbing nutrients from decaying vegetation or other organic matter Examples are the bread molds Rhizopus and Mucor They evolved later than the Ascomycota and Basidiomycota (see Fungi) zygote The diploid cell resulting from the fusion of two haploid GAMETES A zygote usually undergoes cleavage immediately See also embryo zygotene In Zygomycota (zygomycetes) A phylum of FUNGI whose members have haploid, nonseptate hyphae (i.e hyphae without crosswalls) Asexual reproduction is by spores produced in sporangia or by coni- MEIOSIS, the stage in midprophase I that is characterized by the active and specific pairing (synapsis) of homologous chromosomes leading to the formation of a haploid number of bivalents 241 APPENDIXES 245 Chondrichthyes (cartilaginous fish; e.g sharks, rays) Dipnoi (lungfish) Prototheria (monotremes; e.g duckbilled platypus) Metatheria (marsupial mammals; e.g kangaroo, wombat) Mammalia Eutheria (placental mammals; e.g carnivores, bats, whales, rodents, ungulates, primates) Aves (birds) Chilopoda (centipedes) Reptilia (e.g crocodiles, snakes, lizards) Insecta (insects, e.g bugs, beetles, bees, flies) Amphibia (e.g frogs, toads) Teleostei (e.g salmon, plaice, eel) Osteichthyes (bony fish) Crustacea (e.g shrimps, crabs, lobsters) Diplopoda (millipedes) Echinodermata (e.g starfish, sea urchins, brittlestars) Arthropoda Chordata Oligochaeta Polychaeta Hirudinea (earthworms) (e.g (leeches) lugworms) Mollusca Annelida (segmented worms) Pelecypoda Cephalopoda (e.g oysters, (e.g squids, mussels, clams) octopuses) Arachnida (e.g spiders, scorpions, mites) *Only major phyla and classes are shown Agnatha (jawless fish; e.g lampreys, hagfish) Gastropoda (e.g snails, slugs) Turbellaria Trematoda Cestoda (planarians) (flukes) (tapeworms) Cnidaria (i.e Nematoda jellyfish, sea (roundworms) anemones, corals) Porifera Platyhelminthes (sponges) (flatworms) *Animalia Appendix I The Animal Kingdom Appendix II The Plant Kingdom *Plant Lycopodophyta Sphenophyta Filicinophyta (clubmosses) (horsetails) (ferns) Bryophyta Cycadophyta (cycads) Ginkgophyta Coniferophyta (ginkgo) (conifers) gymnosperms Hepaticae (liverworts) Musci (mosses) Angiospermophyta (flowering plants) Monocotyledonae (e.g grasses, orchids, lilies) *Extinct and mostly extinct groups are excluded 246 Dicotyledonae (e.g oak, rose, daisies) Appendix III Webpages The following are university department websites: University of California, Irvine, Department of Ecology and Evolutionary Biology ecoevo.bio.uci.edu/ University of Connecticut, Department of Ecology and Evolutionary Biology www.eeb.uconn.edu/ Harvard University, Department of Organismic and Evolutionary Biology www.oeb.harvard.edu/ Princeton University, Department of Ecology and Evolutionary Biology www.eeb.princeton.edu/ University of Tennessee, Department of Ecology and Evolutionary Biology eeb.bio.utk.edu/ Yale University, Department of Ecology and Evolutionary Biology www.eeb.yale.edu/ There are many museum sites on the Web: American Museum of Natural History www.amnh.org/ Harvard Museum of Natural History www.hmnh.harvard.edu/ Smithsonian Institution National Museum of Natural History www.mnh.si.edu/ The Natural History Museum, London www.nhm.ac.uk/ Yale Peabody Museum of Natural History www.peabody.yale.edu/ A list of annotated evolution links can be found at: Nearctica www.nearctica.com/evolve/evolve.htm Links for Palaeontology can be found at: UK Palaeontological Association www.palass.org/ 247 Bibliography Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; & Walter, Peter Molecular Biology of the Cell 4th ed New York: Garland Science, 2002 Dawkins, Richard The Selfish Gene 2nd ed Oxford, U.K.: Oxford University Press, 1989 Dawkins, Richard The Blind Watchmaker Harlow, U.K.: Longman, 1996 Dawkins, Richard Climbing Mount Improbable Harmondsworth, U.K.: Penguin, 1997 Dixon, Dougal; Jenkins, Ian; Moody, Richard; & Zhuralev, Andrey Cassell’s Atlas of Evolution London, U.K.: Cassell, 2001 Gould, Steven Jay The Panda’s Thumb New York: W W Norton, 1992 Gould, Steven Jay The Structure of Evolutionary Theory Cambridge, Mass.: Harvard University Press, 2002 Jones, Steve Darwin’s Ghost New York: Random House, 2000 Maynard Smith, John Evolutionary Genetics 2nd ed Oxford, U.K.: Oxford University Press, 1998 Maynard Smith, John The Theory of Evolution 2nd ed Cambridge, U.K.: Cambridge University Press, 2000 Mayr, Ernst What Evolution is London, U.K.: Wiedenfeld & Nicholson, 2002 Ridley, Mark Evolution Oxford, U.K.: Blackwell Science, 2003 Zimmer, Carl Evolution London, U.K.: Arrow Books, 2003 248 ...The Facts On File DICTIONARY of EVOLUTIONARY BIOLOGY The Facts On File DICTIONARY of EVOLUTIONARY BIOLOGY Edited by Elizabeth Owen Eve Daintith ® The Facts On File Dictionary of Evolutionary Biology. .. This dictionary is one of a series covering the terminology and concepts used in important branches of science The Facts on File Dictionary of Evolutionary Biology is planned as an additional... permission in writing from the publisher For information contact: Facts On File, Inc 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data The Facts on File dictionary