DOCSLIB.ORG

“Living Together” Symbiosis Phoresis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
“Living Together” Symbiosis Phoresis Microbio590S Lecture 2: Terms and Parasitology Concepts – Example of re- emerging neglected disease Michele Klingbeil Office: Morrill IVN Room 222 By appointment only [email protected] Symbiosis “living together” • Intimate association between two different species – Usually a larger organism is the host, the smaller is the symbiont • Give some examples of symbioses Specific types of association Phoresis - Traveling Together • No dependence from either participant • One participant is usually machanically carried by the other • Hitch-hiking Crab + Barnacle Commensalism • “Sharing at the table” • One partner benefits, but the other is neither helped nor harmed. Clownfish + Sea anemone Mutualism Endosymbiosis - mitochondria • Interspecific interaction that benefits both members • Frequently, the relationship Lichen on tree bark is essential for survival of at least one of the members – Obligate interaction Moray + cleaner wrasse Parasitism • Parasite and parasitism are terms that define a Phoresis and way of life rather than a Commensalism coherent evolutionary related group of organisms. Parasitism Mutualism • Numerous definitions – the intimate association of two species where one species (the parasite) benefits at the expense of the other (the host). – the parasite relies on the host for nutrients and as a place to live. Is this Parasitism? • The benefit in these relationships are clearly skewed toward the lion and the spider. • Predator vs. prey • Predators tend to be larger than their prey, and consume many prey in a lifetime. What is a Parasite? • Parasites are usually much smaller than their host, and do not kill the host before taking a meal. Is This Parasitism? • Micropredation - the mosquito is certainly gaining a nice blood meal. • Blurry lines between these definitions. • The host is the food source, and a specific niche for the parasite. • Many parasites show strict specificity for a single host species. Parasite Diversity! Parasitology as a scientific discipline historically covers a diverse collection of multi- and unicellular eukaryotic organisms Protozoa: unicellular eukaryotes (this is a historic term, protozoans are not really a monophyletic group) Platyhelminthes: flatworms these include flukes and tape worms Nematodes: elongated worms with rigid cuticule Arthropodes: insects, ticks and mites which either are parasitic or transmit parasites as vectors (we only have time to discuss the most important groups causing human and some animal disease, there are many additional parasites outside these groups) Parasite Diversity! • Not a phylogenetically related group of organisms – Single celled eukaryotes - Protists (protozoa) – Mutlicellular worms - Helminths • Many are Vector transmitted disases • Zoonoses - transmission of the infectious agent to humans from an animal reservoir. No establishment of a permanent new life cycle solely in humans (still requires animals). Ecto- vs Endoparasites • Ectoparasites live on, but not in their hosts. Protozoan Ichthyophthirius that causes fish “Ick” Endoparasites live within the body and tissue of their hosts. The majority of parasites to be discussed. Protozoan Trypanosoma that causes African Sleeping sickness. Facultative vs. Obligate • Facultative - usually a free-living organism but can invade host under certain conditions. Can cause Naegleria fowleri severe disease. Obligate - most parasites Trypanosoma cruzi require a host for at least one stage of its life cycle. Some parasitic worms have free-living larval stages. Intermittent vs. Permanent • Intermittent/ temporary - micropredation - “parasite” feeds on the host and then leaves. • Permanent - parasite that lives its entire adult life on or within the host. Most of the parasites we discuss are permanent. Life Cycles Entamoeba histolytica • Direct Life Cycle - parasite passes from one host to the next through contaminated food/water, air, or sexual intercourse. Indirect Life Cycle - parasite passes from one host to the next through a vector and/ Diphyllobothrium or intermediate host. Many latum parasites have complex indirect life cycles. Vectors for Transmission Vectors - Actively transmit parasites • Mechanical Vector - no multiplication or development of parasite takes place. Horse fly • Biological Vector - Tsetse fly either multiplication or development takes place. Transmission of 2 related parasites Tsetse fly Horse fly • Feeds often moving • Proboscus used for front legs and mouth blood meal - longer parts vigorously. feeding period. – Trypanosoma brucei – Trypanosoma evansi bloodstream form is remains on the ingested - develop to mouth parts - no procyclic form - migrate biological and develop to infective development occurs. epimastigotes (new form). Host Definitions • Definitive host - where sexual reproduction occurs. If there is no sexual reproduction documented, then it is the host that is most important to humans. – Typically a vertebrate. Exception - Plasmodium • Intermediate host - where asexual replication or parasite development occurs. • Paratenic host - transport host, but parasites do not develop in this host. • Reservoir host - any animal that carries an infection that can serve as a source of infection to human and other animals. • Accidental host - parasite enters or attaches to other than the normal host. Parasites usually do not survive in the wrong host, but can cause serious disease (Toxocara). Life Cycle Example Intermediate Paratenic Bridging the gap between human Host Host And small fish/copepod. Copepod Monoecious Intermediate Hermaphroditic Host Definitive Diphyllobothrium Host latum Free-swimming stage Summary of Introduction commensalism, mutualism, parasitism, ecto, endo, obligate, facultative, intermittent parasitism …) Hosts (final, intermediate, paratenic, accidental, reservoir …) Disease terminology (infection, infestation, acute, chronic, patency, incubation period, crisis, convalescence …) Parasites Among Us “…no matter how we set ourselves off from nature we remain a part of it, and thus we invariably share parasites with the other species in which we live.” Julius P. Kreier PARASITIC PROTOZOA Emerging Infectious Disease Infectious diseases whose incidence in humans has increased in the past 2 decades or threatens to increase in the near future have been defined as "emerging." These diseases respect no national boundaries include: New infections resulting from changes or evolution of existing organisms (host and/or pathogen) Known infections spreading to new geographic areas or populations Previously unrecognized infections appearing in areas undergoing ecologic transformation Old infections re-emerging as a result of antimicrobial resistance for known agents or breakdowns in public health measures. Emerging(re) Infectious Disease -HIV Species Jumping -Influenza -Hepatitis C and E -E. coli 0157:H7 -Cryptosporidium -Ebola -Hantavirus Zoonoses -Lyme disease -nvCJD -Trypanosomiasis -West Nile Virus Zoonoses Zoonoses - transmission of the infectious agent to humans from an animal reservoir. No establishment of a permanent new life cycle solely in humans (still requires animals). Species jumping - the infectious agent derives from an ancient animal reservoir, but has established a new life cycle in humans that DOES NOT require an animal transmission phase any longer. Contributing Factors for Zoonoses Pathogen evolution (adaptation) Mutations Host condition Vaccination Immunological disorders Host population Urban crowding (land use) Host demographics & behavior Global travel Environmental Climate Destruction Public Health breakdown Dealing with Zoonoses Why are the pathogens jumping? Can we predict this? Who will be the world’s doctor? WHO, UN - need to get rid of political links? Who will be the world’s expert on zoonoses? Develop new strategies to deal specifically with emerging zoonoses. Surveillance will be key, but also greater involvement of field and basic science research. Numbers of People with Parasitic Diseases Disease with HIGH morbidity Disease with HIGH mortality: and QL losses: – Malaria - 489 M – Schistosomiasis - 200 M – Sleeping Sickness 0.5 M – Onchocerciasis - 37 M – Filiariasis - 350 M – Chagas disease - 18 M – Ascariasis – 807 M – Visceral Leishmaniasis - 4 M – Hookworm diseases – 600 M – Trichuriasis – 605 M – Cutaneous leishmaniasis - 8 M – Food and waterborne Estimated World Pop by UN protozoan - 1.5 B 10/31/11 7 Billion Human African Trypanosomiasis • Classical example of a zoonotic emerging infection, 1890-1930. • Leading public health problem in Africa at that time, colonialism brought the disease to new areas with a 2/3 death rate. • Nearly eliminated by 1960 using population screening, case treatment, chemoprophylaxis, and vector control. • Currently classified by WHO as a re-emerging and uncontrolled disease. HATHAT Nearly Nearly Eliminated Eliminated in in 1960s 1960! Human African Trypanosomiasis, central Africa, 1926-1999 HAT: re-emerging, Neglected Tropical Disease How Was Control Successful? ……..and now Anion Exchange Card agglutination Test Molecular Tools Centrifugation Technique Time consuming Sensitive Expensive Still under development Additional equipment Large # of false +’s Estimating Disease Burden > 60 M people at risk, only about 3-6 M are screened for HAT. Health facilities lacking in disease foci areas. Little if any public health measures being implemented. Huge political conflict and insecurity in epidemic foci. Clinical diagnosis is difficult until late stage. Intermittent fever
Load more

Recommended publications
  • Plant-Microbe Symbioses: a Continuum from Commensalism to Parasitism
    UCLA UCLA Previously Published Works Title Plant-microbe symbioses: A continuum from commensalism to parasitism Permalink https://escholarship.org/uc/item/6kx779h1 Journal Symbiosis, 37(1-3) ISSN 0334-5114 Author Hirsch, Ann M. Publication Date 2004 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Symbiosis, 37 (2004) xx–xx 1 Balaban, Philadelphia/Rehovot Review article. Plant-Microbe Symbioses: A Continuum from Commensalism to Parasitism ANN M. HIRSCH Department of Molecular, Cell, and Developmental Biology and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA, Tel. +1-310-206-8673, Fax. +1-310-206-5413, Email. [email protected] Received October 28, 2003; Accepted January 27, 2004 Abstract Photosynthetic organisms establish symbioses with a wide range of microorganisms. This review examines the diversity of symbiotic interactions, and proposes that there is a continuum from commensalism to mutualism to pathogenesis/parasitism in plant-microbe associations. The advantage of considering commensalism, mutualism, and pathogenesis/parasitism as a continuum rather than as discrete relationships between hosts and microbes, as they have been considered in the past, is that it will motivate us to focus more on common molecular mechanisms. Keywords: ?? 1. Introduction Plants establish mutualistic, often described as symbiotic, interactions with myriad organisms, both prokaryotic and eukaryotic. Some of the most prominent photosynthetic mutualisms are illustrated in Fig. 1. Although technically not a plant symbiosis, lichens are photosynthetic and represent an excellent example of a beneficial interaction (Fig. 1A). Presented at the 4th International Symbiosis Congress, August 17–23, 2003, Halifax, Canada 0334-5114/2004/$05.50 ©2004 Balaban 2 A.M.
    [Show full text]
  • Coming to Terms with a Field: Words and Concepts in Symbiosis
    Symbiosis, 14 (1992) 17-31 17 Balaban, Philadelphia/Rehovot Review article Coming to Terms with a Field: Words and Concepts in Symbiosis MARY BETH SAFFO Institute of Marine Sciences, University of California Santa Cruz, CA 95064, USA Tel. ( 408) 459 4997, Fax ( 408) 459 4882 Received March 29, 1992; Accepted May 5, 1992 Abstract More than a century after de Bary (1879) adopted the term symbiosis, biolo• gists still disagree about the word's meaning. Many researchers define symbiosis in the sense of de Bary, as an intimate, outcome-independent interaction between species; others use symbiosis as a synonym for mutualistic or non-parasitic as• sociations. This varied usage arises in part from the absence of a language for describing both symbiotic and non-symbiotic mutualistic interactions; the complexity of many "mutualistic" endosymbiosesposes a particular descriptive difficulty. Expropriation of "symbiosis" to identify these mutualistic associa• tions is an understandable, but ultimately confusing, and conceptually limiting solution to this problem. Retention of the broad, outcome-independent sense of symbiosis is urged. Alternate terms, including chronic endosymbiosis, are proposed for apparently benign symbioses which are too poorly known, or too complex, to categorize comfortably as "mutualistic." In addition to outcome-independent investigations of symbiotic phenomena, questions of the evolutionary significance of symbioses are difficult, but im• portant problems. Thus, terms which address particular outcomes for host or symbiont - e.g., parasitism, commensalism and mutualism, "costs," "bene• fits," fitness, and related terms - also have a place in the language of symbiosis research. 0334-5114/92 /$03.50 ©1992 Balaban 18 M.B. SAFFO Habits of language ..
    [Show full text]
  • Phylogenetic Diversity of Bacterial Endosymbionts in the Gutless Marine Oligochete Olaviusloisae (Annelida)
    MARINE ECOLOGY PROGRESS SERIES Vol. 178: 271-280.1999 Published March 17 Mar Ecol Prog Ser l Phylogenetic diversity of bacterial endosymbionts in the gutless marine oligochete Olavius loisae (Annelida) Nicole ~ubilier'~*,Rudolf ~mann',Christer Erseus2, Gerard Muyzer l, SueYong park3, Olav Giere4, Colleen M. cavanaugh3 'Molecular Ecology Group, Max Planck Institute of Marine Microbiology, Celsiusstr. 1. D-28359 Bremen, Germany 'Department of Invertebrate Zoology. Swedish Museum of Natural History. S-104 05 Stockholm. Sweden 3~epartmentof Organismic and Evolutionary Biology, Harvard University, The Biological Laboratories, Cambridge, Massachusetts 02138, USA 4Zoologisches Institut und Zoologisches Museum. University of Hamburg, D-20146 Hamburg, Germany ABSTRACT: Endosymbiotic associations with more than 1 bacterial phylotype are rare anlong chemoautotrophic hosts. In gutless marine oligochetes 2 morphotypes of bacterial endosymbionts occur just below the cuticle between extensions of the epidermal cells. Using phylogenetic analysis, in situ hybridization, and denaturing gradient gel electrophoresis based on 16s ribosomal RNA genes, it is shown that in the gutless oligochete Olavius Ioisae, the 2 bacterial morphotypes correspond to 2 species of diverse phylogenetic origin. The larger symbiont belongs to the gamma subclass of the Proteobac- tend and clusters with other previously described chemoautotrophic endosymbionts. The smaller syrnbiont represents a novel phylotype within the alpha subclass of the Proteobacteria. This is distinctly cllfferent from all other chemoautotropl-uc hosts with symbiotic bacteria which belong to either the gamma or epsilon Proteobacteria. In addition, a third bacterial morphotype as well as a third unique phylotype belonging to the spirochetes was discovered in these hosts. Such a phylogenetically diverse assemblage of endosymbiotic bacteria is not known from other marine invertebrates.
    [Show full text]
  • The Symbiotic Life of Symbiodinium in the Open Ocean Within a New Species of Calcifying Ciliate (Tiarina Sp.)
    The ISME Journal (2016) 10, 1424–1436 © 2016 International Society for Microbial Ecology All rights reserved 1751-7362/16 www.nature.com/ismej ORIGINAL ARTICLE The symbiotic life of Symbiodinium in the open ocean within a new species of calcifying ciliate (Tiarina sp.) Solenn Mordret1,2,5, Sarah Romac1,2, Nicolas Henry1,2, Sébastien Colin1,2, Margaux Carmichael1,2, Cédric Berney1,2, Stéphane Audic1,2, Daniel J Richter1,2, Xavier Pochon3,4, Colomban de Vargas1,2 and Johan Decelle1,2,6 1EPEP—Evolution des Protistes et des Ecosystèmes Pélagiques—team, Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff, Roscoff, France; 2CNRS, UMR 7144, Station Biologique de Roscoff, Roscoff, France; 3Coastal and Freshwater Group, Cawthron Institute, Nelson, New Zealand and 4Institute of Marine Science, University of Auckland, Auckland, New Zealand Symbiotic partnerships between heterotrophic hosts and intracellular microalgae are common in tropical and subtropical oligotrophic waters of benthic and pelagic marine habitats. The iconic example is the photosynthetic dinoflagellate genus Symbiodinium that establishes mutualistic symbioses with a wide diversity of benthic hosts, sustaining highly biodiverse reef ecosystems worldwide. Paradoxically, although various species of photosynthetic dinoflagellates are prevalent eukaryotic symbionts in pelagic waters, Symbiodinium has not yet been reported in symbiosis within oceanic plankton, despite its high propensity for the symbiotic lifestyle. Here we report a new pelagic photosymbiosis between a calcifying ciliate host and the microalga Symbiodinium in surface ocean waters. Confocal and scanning electron microscopy, together with an 18S rDNA-based phylogeny, showed that the host is a new ciliate species closely related to Tiarina fusus (Colepidae).
    [Show full text]
  • PARASITES PREDATORS and SYMBIONTS a Thesis Submitted To
    PARASITES PREDATORS AND SYMBIONTS A thesis submitted to the College of the Arts of Kent State University in partial fulfillment of the requirements for the degree of Master of Fine Arts By Jody L. Vankeuren May 2021 Thesis written by Jody L. Vankeuren B.F.A., Edinboro University of Pennsylvania, 2018 M.F.A., Kent State University, 2021 Approved by Andrew Kuebeck, M.F.A., Advisor Marie Buukowski, M.F.A., Director, School of Art John R. Crawford- Spinelli, Ed.D., Dean, College of the Arts TABLE OF CONTENTS Page LIST OF FIGURES ......................................................................................................................................................... IV AKNOWLEDGEMENTS ............................................................................................................................................. V CHAPTER 1. INTRODUCTION .................................................................................................................................................. 1 2. RESEARCH ............................................................................................................................................................. 1 3. PARASITES PREDATORS AND SYMBIONTS- INDIVIDUAL WORKS ............................................. 4 4. INSTALATION ...................................................................................................................................................... 8 5. CONCLUSION .......................................................................................................................................................
    [Show full text]
  • Symbiosis: Living Together
    Biology Symbiosis: Living together When different species live together in close contact, they can interact with each other in a number of different ways. In this lesson you will investigate the following: • What are the types of symbiosis? • What is parasitism? • What are the different types of parasite-host relationships? • What’s it like to be a parasite? So let’s get stuck in and start sucking the life out of this lesson! This is a print version of an interactive online lesson. To sign up for the real thing or for curriculum details about the lesson go to www.cosmosforschools.com Introduction: Symbiosis (P1) Cuckoos are known for not building their own nests. Instead these birds let someone else do all the work to build a nest, then lay their eggs there. They don’t even wait around to bring up their chicks when they hatch – they let the other birds do that too. Scientists have just discovered how they have been getting away with this for so long. While having an extra mouth to feed is a burden, it seems the cuckoos do provide something useful in exchange. While studying crows’ breeding habits in Spain, scientists saw lots of cuckoos laying eggs in crows’ nests and magpies’ nests. The magpies fought back and threw out the cuckoo eggs (if they noticed them). But the crows allowed the eggs to stay, letting them hatch and then feeding the cuckoo chicks as they grew. Curious, the scientists investigated, taking note of how well the crows with cuckoos did compared to crows without a cuckoo tenant.
    [Show full text]
  • Non-Invasive Sampling in Itatiaia National Park, Brazil: Wild Mammal Parasite Detection
    Dib et al. BMC Veterinary Research (2020) 16:295 https://doi.org/10.1186/s12917-020-02490-5 RESEARCH ARTICLE Open Access Non-invasive sampling in Itatiaia National Park, Brazil: wild mammal parasite detection Laís Verdan Dib1, João Pedro Siqueira Palmer1, Camila de Souza Carvalho Class1, Jessica Lima Pinheiro1, Raissa Cristina Ferreira Ramos1, Claudijane Ramos dos Santos1, Ana Beatriz Monteiro Fonseca2, Karen Gisele Rodríguez-Castro3, Camila Francisco Gonçalves3, Pedro Manoel Galetti Jr.3, Otilio Machado Pereira Bastos1, Claudia Maria Antunes Uchôa1, Laís Lisboa Corrêa1, Augusto Cezar Machado Pereira Bastos1, Maria Regina Reis Amendoeira4 and Alynne da Silva Barbosa1,4* Abstract Background: Non-invasive sampling through faecal collection is one of the most cost-effective alternatives for monitoring of free-living wild mammals, as it provides information on animal taxonomy as well as the dynamics of the gastrointestinal parasites that potentially infect these animals. In this context, this study aimed to perform an epidemiological survey of gastrointestinal parasites using non-invasive faecal samples from carnivores and artiodactyls identified by stool macroscopy, guard hair morphology and DNA sequencing in Itatiaia National Park. Between 2017 and 2018, faeces from carnivores and artiodactyls were collected along trails in the park. The host species were identified through macroscopic and trichological examinations and molecular biology. To investigate the parasites, the Faust, Lutz and modified Ritchie and Sheather techniques and enzyme immunoassays to detect Cryptosporidium sp. antigens were used. Results: A total of 244 stool samples were collected. The species identified were Chrysocyon brachyurus, Leopardus guttulus, Canis familiaris, Cerdocyon thous, Puma yagouaroundi, Leopardus pardalis, Puma concolor and Sus scrofa.Therewere81.1% samples that were positive for parasites distributed mainly in the high part of the park.
    [Show full text]
  • Human Evolution
    Note added by authors December 4, 2018: This study is grounded in and strongly supports Darwinian evolution, including the understanding that all life has evolved from a common biological origin over several billion years. This work follows mainstream views of human evolution. We do not propose there was a single "Adam" or "Eve". We do not propose any catastrophic events. HUMAN EVOLUTION Vol. 33 - n. 1-2 (1-30) - 2018 Stoeckle M.Y. Why should mitochondria define species? Program for the Human Environment The Rockefeller University 1230 York AVE More than a decade of DNA barcoding encompassing New York, NY 10065 about five million specimens covering 100,000 animal USA species supports the generalization that mitochondrial Email: [email protected] DNA clusters largely overlap with species as defined by domain experts. Most barcode clustering reflects synony- Thaler D.S. mous substitutions. What evolutionary mechanisms ac- Biozentrum, University of Basel count for synonymous clusters being largely coincident Klingelbergstrasse 50/70 with species? The answer depends on whether variants CH - 4056 Basel Switzerland are phenotypically neutral. To the degree that variants are Email: [email protected] selectable, purifying selection limits variation within spe- [email protected] cies and neighboring species may have distinct adaptive peaks. Phenotypically neutral variants are only subject to demographic processes—drift, lineage sorting, genetic DOI: 10.14673/HE2018121037 hitchhiking, and bottlenecks. The evolution of modern humans has been studied from several disciplines with detail unique among animal species. Mitochondrial bar- codes provide a commensurable way to compare modern humans to other animal species. Barcode variation in the modern human population is quantitatively similar to that within other animal species.
    [Show full text]
  • Worms, Germs, and Other Symbionts from the Northern Gulf of Mexico CRCDU7M COPY Sea Grant Depositor
    h ' '' f MASGC-B-78-001 c. 3 A MARINE MALADIES? Worms, Germs, and Other Symbionts From the Northern Gulf of Mexico CRCDU7M COPY Sea Grant Depositor NATIONAL SEA GRANT DEPOSITORY \ PELL LIBRARY BUILDING URI NA8RAGANSETT BAY CAMPUS % NARRAGANSETT. Rl 02882 Robin M. Overstreet r ii MISSISSIPPI—ALABAMA SEA GRANT CONSORTIUM MASGP—78—021 MARINE MALADIES? Worms, Germs, and Other Symbionts From the Northern Gulf of Mexico by Robin M. Overstreet Gulf Coast Research Laboratory Ocean Springs, Mississippi 39564 This study was conducted in cooperation with the U.S. Department of Commerce, NOAA, Office of Sea Grant, under Grant No. 04-7-158-44017 and National Marine Fisheries Service, under PL 88-309, Project No. 2-262-R. TheMississippi-AlabamaSea Grant Consortium furnish ed all of the publication costs. The U.S. Government is authorized to produceand distribute reprints for governmental purposes notwithstanding any copyright notation that may appear hereon. Copyright© 1978by Mississippi-Alabama Sea Gram Consortium and R.M. Overstrect All rights reserved. No pari of this book may be reproduced in any manner without permission from the author. Primed by Blossman Printing, Inc.. Ocean Springs, Mississippi CONTENTS PREFACE 1 INTRODUCTION TO SYMBIOSIS 2 INVERTEBRATES AS HOSTS 5 THE AMERICAN OYSTER 5 Public Health Aspects 6 Dcrmo 7 Other Symbionts and Diseases 8 Shell-Burrowing Symbionts II Fouling Organisms and Predators 13 THE BLUE CRAB 15 Protozoans and Microbes 15 Mclazoans and their I lypeiparasites 18 Misiellaneous Microbes and Protozoans 25 PENAEID
    [Show full text]
  • Symbiosis in the Microbial World: from Ecology to Genome Evolution Jean-Baptiste Raina1,*, Laura Eme2, F
    © 2018. Published by The Company of Biologists Ltd | Biology Open (2018) 7, bio032524. doi:10.1242/bio.032524 REVIEW Symbiosis in the microbial world: from ecology to genome evolution Jean-Baptiste Raina1,*, Laura Eme2, F. Joseph Pollock3, Anja Spang2,4, John M. Archibald5 and Tom A. Williams6,* ABSTRACT functionally diverse organisms on the planet, the microbes The concept of symbiosis – defined in 1879 by de Bary as ‘the living (which comprise bacteria, archaea and protists, as well as the together of unlike organisms’–has a rich and convoluted history in viruses that infect them), and their interactions with multicellular biology. In part, because it questioned the concept of the individual, hosts. These microbial symbioses range from metabolic symbiosis fell largely outside mainstream science and has (McCutcheon and Moran, 2012) and defensive interactions traditionally received less attention than other research disciplines. (Oliver et al., 2014) among free-living organisms, to the This is gradually changing. In nature organisms do not live in isolation complete cellular and genomic integration that occurred during but rather interact with, and are impacted by, diverse beings the endosymbiotic origins of mitochondria and chloroplasts in throughout their life histories. Symbiosis is now recognized as a eukaryotic cells (Embley and Martin, 2006; Roger et al., 2017). central driver of evolution across the entire tree of life, including, for Symbiosis provides an unparalleled route to evolutionary example, bacterial endosymbionts that provide insects with vital innovation, one that underlies some of the most important nutrients and the mitochondria that power our own cells. Symbioses transitions in the history of life.
    [Show full text]
  • Simply Symbiosis! Symbiotic Relationships
    (circle) Name: _______________________________________ Period : 1 4 5 6 7 Simply Symbiosis! Background The word symbiosis was first defined as “unlike organisms living together”. The relationship between these two unlike organisms can be positive, negative or neutral. There are three types of symbiotic relationships- mutualism, commensalism and parasitism. Mutualism is when both organisms benefit from each other like the African crocodile and the blackbird plover- the bird gets nutrients from left over food material in the mouth of the crocodile and the crocodile has cleaner teeth because of the bird. Commensalism is when one organism benefits from the relationship, while the other one is neither helped nor harmed. An example of commensalism is a barnacle on a whale. The barnacle gets protection and transportation to different food sources while the whale is neither helped nor harmed by the presence of the barnacle. The last example of symbiosis is parasitism. This is when one organism benefits but while doing so it is harming the other member in the relationship. A common example of this is a flea on a dog. The flea obtains nutrients and protection from the dog but the dog has an uncomfortable skin reaction because of the flea. Pre Lab Assignment Complete the concept map about symbiotic relationships using the word bank below. One benefits/One is harmed Both benefit Parasitism One benefits/One not helped nor harmed Mutualism Commensalism Symbiotic Relationships Skills Applications Concepts pg. 1 Lab Assignment Read and complete each step of the lab below. 1. Purpose: The purpose of this lab is to determine the type of symbiotic relationships between two unlike organisms found in nature.
    [Show full text]
  • Why Should Mitochondria Define Species?
    HUMAN EVOLUTION Vol. 33 - n. 1-2 (1-30) - 2018 Stoeckle M.Y. Why should mitochondria define species? Program for the Human Environment The Rockefeller University 1230 York AVE More than a decade of DNA barcoding encompassing New York, NY 10065 about five million specimens covering 100,000 animal USA species supports the generalization that mitochondrial Email: [email protected] DNA clusters largely overlap with species as defined by domain experts. Most barcode clustering reflects synony- Thaler D.S. mous substitutions. What evolutionary mechanisms ac- Biozentrum, University of Basel count for synonymous clusters being largely coincident Klingelbergstrasse 50/70 with species? The answer depends on whether variants CH - 4056 Basel Switzerland are phenotypically neutral. To the degree that variants are Email: [email protected] selectable, purifying selection limits variation within spe- [email protected] cies and neighboring species may have distinct adaptive peaks. Phenotypically neutral variants are only subject to demographic processes—drift, lineage sorting, genetic DOI: 10.14673/HE2018121037 hitchhiking, and bottlenecks. The evolution of modern humans has been studied from several disciplines with detail unique among animal species. Mitochondrial bar- codes provide a commensurable way to compare modern humans to other animal species. Barcode variation in the modern human population is quantitatively similar to that within other animal species. Several convergent lines of evidence show that mitochondrial diversity in modern humans follows from sequence uniformity followed by the accumulation of largely neutral diversity during a population expansion that began approximately 100,000 years ago. A straightforward hypothesis is that the extant populations of almost all animal species have arrived at KEY WORDS: Species evolution, a similar result consequent to a similar process of expan- mitocondrial evolution, speciation, sion from mitochondrial uniformity within the last one to human evolution.
    [Show full text]