DOCSLIB.ORG

Evolutionary Theories of Aging"

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Evolutionary Theories of Aging Article ID: WMC003275 ISSN 2046-1690 The Germ-soma Conflict Theory of Aging and Death: Obituary to the "Evolutionary Theories of Aging" Corresponding Author: Prof. Kurt Heininger, Professor, Department of Neurology, Heinrich Heine University Duesseldorf - Germany Submitting Author: Prof. Kurt Heininger, Professor, Department of Neurology, Heinrich Heine University Duesseldorf - Germany Article ID: WMC003275 Article Type: Original Articles Submitted on:20-Apr-2012, 01:51:59 PM GMT Published on: 20-Apr-2012, 05:38:59 PM GMT Article URL: http://www.webmedcentral.com/article_view/3275 Subject Categories:AGING Keywords:Aging, Reproduction, Evolution, Darwinian demon, Resources How to cite the article:Heininger K. The Germ-soma Conflict Theory of Aging and Death: Obituary to the "Evolutionary Theories of Aging" . WebmedCentral AGING 2012;3(4):WMC003275 Copyright: This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source(s) of Funding: No funding Competing Interests: No competing interests Additional Files: References WebmedCentral > Original Articles Page 1 of 139 WMC003275 Downloaded from http://www.webmedcentral.com on 30-Apr-2012, 10:35:59 AM The Germ-soma Conflict Theory of Aging and Death: Obituary to the "Evolutionary Theories of Aging" Author(s): Heininger K Abstract “cheater” phenotypes that are defective to carry the cost of death at reproductive events are less fit under conditions of feast and famine cycles and have a high risk to go extinct. Tracing both the genomic and Regarding aging, the scientific community persists in a physiological “fossil record” and the phenotypic pattern state of collective schizophrenia. This state is owed to throughout phylogenesis demonstrates that evolution the so-called “evolutionary theories of aging”. succeeded to enforce this general principle in According to these theories, aging, following the multicellular unitary organisms by creating a peri-/postreproductive decline of selection pressure, is dichotomy between soma and germline cells, making posited to be haphazard, not selected for, not adaptive, the former the mortal breeder and the latter the and not programmed. And yet, defying these concepts, virtually immortal genetic vector. Importantly, germline aging is phylogenetically conserved and subject to cells control the longevity of the soma from ‘within’ by regulation by classical signaling pathways and a variety of signals, e.g. sexual hormones. These transcription factors. While some blatantly deny this signals, on the one hand, make the mature organism genetic control, others (particularly geneticists) appear vital and attractive for mates and, on the other hand, to accommodate with the obvious incompatibilities. limit the reproductive potential of the parent organism First it is shown that the “evolutionary theories of aging” and drive a variety of aging pacemakers, particularly are based on circular reasoning and fallacious post the senescene of the immune system. hoc, ergo propter hoc argumentations and that their The transgenerational conflict between germline cells basic assumptions are flawed. Second, by a simple and soma over utilization of limited resources is the change of perspective, replacing a soma-centered (as evolutionary rationale of postreproductive aging/death, in the “evolutionary theories of aging”) by a semelparous organisms being a particularly drastic germline-centered point of view and based on witness of the link between reproduction and death. compelling evidence from more than 400,000 scientific Semelparity and iteroparity are threshold traits and as publications (of which more than 4,000 have been such opposite ends of a continuum of life history referenced in this work) a non-group-selective, variation rather than representing fundamentally evolutionary mechanism is elaborated that explains different life history strategies. Although the cost of the co-selection and programming of reproduction and reproduction, e.g. in terms of impaired aging/death. immunocompetence and survival, still shapes the life A gedankenexperiment reveals: A Darwinian demon history trade-offs of iteroparous organisms, the that exhibits both immortality and infinite reproduction temporal uncoupling of reproduction and death is not viable in a world of limited resources. According concealed their evolutionary co-selection. Death in the to the phylogenetic record and deep genetic natural habitat due to environmental hazards such as homologies, death of the soma is identified as the predation, infection, accident, or starvation often ultimate cost of reproduction. At the evolutionary base predates the germ signaling-dependent demise and of the unicellular/multicellular transition, microbial may hinder the individuals to exploit their full longevity organisms have a “feast and famine” lifestyle. potential. A protected environment, however, like in Following the exhaustion of a resource, they build human societies, laboratories and captivity unmasks multicellular structures that generate spores that can the process of aging. resist the nutrient-depleted environment. The In contrast to unitary organisms, modular organisms metamorphosis to spores is fuelled by energy and (e.g. plants, benthic aquatic invertebrates) that have building blocks provided by the – not altruistic, but no segregated germline and in which the adult body rather spore-induced cytocidal – death of clonal itself is a reproductive unit, may evade senescence. siblings. Their phenotypes identify these processes as However, they are subject to territorial, ancient reproductive events creating distinct density-dependent mortality patterns, due to e.g. generations: germs (that can germinate later under self-thinning or chemical warfare, and density-limited more favorable conditions) and fruiting bodies (that seed recruitment driven by interindividual competition nurse and disseminate the spores and die). In contrast, for resources. Thus, the different lifestyle of sessile WebmedCentral > Original Articles Page 2 of 139 WMC003275 Downloaded from http://www.webmedcentral.com on 30-Apr-2012, 10:35:59 AM organisms (being unable to move away from local apoptosis, reproduction, and post-reproductive death resource competition) and mobile organisms (that, 7. Semelparous and iteroparous life-history strategies even when dispersing take their internal “competitor” 7.1 Aging is a corollary of iteroparous reproduction with them) determined their transgenerational 7.2 Plasticity of semelparous and iteroparous resource management systems. The germ-soma life-history strategies conflict shaped the different bauplans of unitary and 8. The costs of reproduction modular organisms, is the motor driving animal 8.1 Germ cells exact at least part of the costs of coevolutionary “Red Queen” dynamics and possibly reproduction fuelled the Cambrian explosion of animals. 9. Reproduction and aging/death: modulated by This update of the evidence-based germ-soma conflict resource availability and utilization theory (Heininger, 2002a) integrates the wealth of data 9.1 Diapause and hibernation: metabolic dormancy as in a holistic eco-evo-devo approach. The germ-soma response to environmental dearth conflict theory takes into account and explains the 9.2 Dietary restriction, aging and reproduction known facts related to aging and postreproductive 9.3 Nutrient and energy-sensing pathways, death: the near-universality, the genetic programming, reproduction and aging and the reproduction-, resource-utilization-, and 9.4 Phosphate and aging stress-resistance-dependent modulation (including 10. Stress and aging such phenomena as late-life mortality plateaus and 10.1 Stress resistance, hormesis and aging/death gender dimorphic life expectancies). This change of 10.2 The general and oxidative stress of aging paradigm resolves the inconsistencies of the 10.3 The metabolic stress of aging pseudoevolutionary and unjustifiably so-called 10.3.1 Klotho, key pleiotropic node of the resource “evolutionary theories of aging” and roots the utilization-stress-aging network phylogenetically conserved programming of aging and 10.4 The organism, its stress response and aging death solidly in the evolutionary theories of Darwin, 11. Germline cells engender somatic aging and death Wallace and Weismann 11.1 Reproductive maturity and lifespan: a temporal Table of Contents relationship 1. Introduction 11.2 Germline signals drive somatic aging 2. The “Structure of Scientific Revolutions” 11.2.1 Prokaryotes 2.1 The Structure of Scientific Revolutions 11.2.2 Basal eukaryotes 2.2 Interconnected thinking 11.2.3 Plants 2.3 The “Law of Causality” 11.2.4 Metazoa 3. Aging is due to the declining force of natural 11.3 Immunocompetence, a key target of germ cell selection: a fata morgana signaling 4. Gedankenexperiment: Darwinian demon 11.3.1 Immunosuppressive action of reproductive 5. The limited resources paradigm and the “tragedy of activity the commons” 11.3.2 Immunosenescence 5.1 Reproduction outgrows resources 11.4 Germline-derived signals limit the soma’s 5.2 Resource limitation is a pervasive ecological reproductive potential phenomenon 12. The germ-soma conflict 5.3 Competion for food and space in plants and 12.1 The physiognomy of conflict: yin and yang sessile animals 12.2 Multicellularity and conflict 5.4 The Tragedy of the Commons 12.3 Mediation of germ-soma conflict by antagonistic 5.5
Load more

Recommended publications
  • Metaheuristics1
    METAHEURISTICS1 Kenneth Sörensen University of Antwerp, Belgium Fred Glover University of Colorado and OptTek Systems, Inc., USA 1 Definition A metaheuristic is a high-level problem-independent algorithmic framework that provides a set of guidelines or strategies to develop heuristic optimization algorithms (Sörensen and Glover, To appear). Notable examples of metaheuristics include genetic/evolutionary algorithms, tabu search, simulated annealing, and ant colony optimization, although many more exist. A problem-specific implementation of a heuristic optimization algorithm according to the guidelines expressed in a metaheuristic framework is also referred to as a metaheuristic. The term was coined by Glover (1986) and combines the Greek prefix meta- (metá, beyond in the sense of high-level) with heuristic (from the Greek heuriskein or euriskein, to search). Metaheuristic algorithms, i.e., optimization methods designed according to the strategies laid out in a metaheuristic framework, are — as the name suggests — always heuristic in nature. This fact distinguishes them from exact methods, that do come with a proof that the optimal solution will be found in a finite (although often prohibitively large) amount of time. Metaheuristics are therefore developed specifically to find a solution that is “good enough” in a computing time that is “small enough”. As a result, they are not subject to combinatorial explosion – the phenomenon where the computing time required to find the optimal solution of NP- hard problems increases as an exponential function of the problem size. Metaheuristics have been demonstrated by the scientific community to be a viable, and often superior, alternative to more traditional (exact) methods of mixed- integer optimization such as branch and bound and dynamic programming.
    [Show full text]
  • The Journal of the Palo Alto Institute
    PAI is a 501(c)(3) nonprofit Vol. 5 creativity laboratory, The Journal of the dedicated to the pursuit February 2012 and promotion of unconventional truths ISSN: 1948–7843 through research, Palo Alto Institute education and entertainment. E-ISSN: 1948–7851 Future of Human Evolution 1 Status Update 13 Food Allergy, Asthma, Anaphylaxis, and Autonomic Dysfunction 17 10x 22 Therapeutics as the Next Frontier in the Evolution of Darwinian Medicine 24 Future of Human Evolution Palo Alto Institute Joon Yun February 2012, Vol. 5 DOI: 10.3907 / FHEJ5P Programmed Death Is senescence (biologic death) a programmed trait? Perhaps no topic in evolutionary biology evokes more controversy. Senescence was once assumed to be the result of so-called "wear and tear"; namely, an organism ages and eventually fails as it accumulates defects that are insufficiently corrected. However, the existence of senescence is not a thermodynamic necessity. Although entropy must increase within a closed system, organisms are not closed systems unto themselves. Since it can extract free energy from the environment and reduce its own entropy, an organism typically grows more resilient from seed stage to reproductive maturity. Indeed, life tables for humans suggest that the lowest likelihood of death in females occurs around the age of 14, which coincides with the prehistoric age of reproductive maturity. Organisms appear to be capable of self-repair when beneficial; indeed, certain organisms such as Hydra do not exhibit signs of senescence. However, most organisms undergo a failure of repair mechanisms, an increase in entropy, and an emergence of senescence after reproductive age—despite having free energy available around them.
    [Show full text]
  • Aging by Design
    Aging by Design How New Thinking on Aging Will Change Your Life Theodore C. Goldsmith Copyright © 2011 Azinet Press ISBN: 978-0-9788709-3-5 ISBN-10: 0-9788709-3-X Amazon Kindle Edition ASIN: B005KCO8SS Azinet Press Box 239 Crownsville, MD 21032 1-410-923-4745 Keywords: senescence, anti-aging medicine, ageing, evolution, gerontology This book contains some material previously published in An Introduction to Biological Aging Theory Pictures and illustrations courtesy of Wikipedia unless otherwise noted. 22,500 words, 49 pages (8.5 x 11 inch format), 7 illus. August 22, 2011 2 Contents Introduction......................................................................................................................... 4 Ages of Man – Human Mortality........................................................................................ 5 A Brief Summary of Aging Theories.................................................................................. 6 The Evolution of Aging ...................................................................................................... 7 Medawar’s Modification to Darwin’s Theory .................................................................. 11 Williams’ Modification to Darwin’s Theory .................................................................... 12 Evolution Theory’s Individual Benefit Clause ................................................................. 14 More Discrepancies with Traditional Darwinism – Group Selection............................... 15 More Discrepancies – Evolvability
    [Show full text]
  • Drought Tolerance Associated with Proline and Hormone Metabolism
    TURF MANAGEMENT HORTSCIENCE 46(7):1027–1032. 2011. the most common naturally occurring cyto- kinins (Strivastava, 2002). Bano et al. (1993) noted that cytokinin concentration in xylem Drought Tolerance Associated with sap declined after water deprivation and in- creased again after re-watering. It has been Proline and Hormone Metabolism documented that the plants with higher cyto- kinins exhibited greater drought tolerance in Two Tall Fescue Cultivars and exogenous cytokinins (such as zeatin riboside) can improve turfgrass tolerance to Da Man, Yong-Xia Bao, and Lie-Bao Han1,2 drought stress (Zhang and Ervin, 2004; Turfgrass Research Institute, Beijing Forestry University, Beijing, China Zhang and Schmidt, 1999, 2000). IAA is 100083 associated with root initiation and growth (Nordstrom et al., 1991; O’Donnell, 1973) Xunzhong Zhang1,2 Recent study has shown that leaf tissue IAA Department of Crop and Soil Environmental Sciences, Virginia Polytechnic content was positively correlated with drought tolerance and exogenous indole-3-butyric Institute and State University, Blacksburg, VA 24041 acid increased endogenous IAA and im- Additional index words. drought tolerance, hormone, physiology, proline, tall fescue proved tall fescue drought tolerance (Zhang et al., 2005, 2009). It was also reported IAA Abstract. Drought stress is a major factor in turfgrass management; however, the content increased as plants adapted to drought underlying mechanisms of turfgrass drought tolerance are not well understood. This stress (Pustovoitova et al., 2004; Sakurai et al., greenhouse study was designed to investigate proline and hormone responses to drought 1985). stress in two tall fescue [Festuca arundinacea (Schreb.)] cultivars differing in drought Tall fescue [Festuca arundinacea tolerance.
    [Show full text]
  • Fish, Various Invertebrates
    Zambezi Basin Wetlands Volume II : Chapters 7 - 11 - Contents i Back to links page CONTENTS VOLUME II Technical Reviews Page CHAPTER 7 : FRESHWATER FISHES .............................. 393 7.1 Introduction .................................................................... 393 7.2 The origin and zoogeography of Zambezian fishes ....... 393 7.3 Ichthyological regions of the Zambezi .......................... 404 7.4 Threats to biodiversity ................................................... 416 7.5 Wetlands of special interest .......................................... 432 7.6 Conservation and future directions ............................... 440 7.7 References ..................................................................... 443 TABLE 7.2: The fishes of the Zambezi River system .............. 449 APPENDIX 7.1 : Zambezi Delta Survey .................................. 461 CHAPTER 8 : FRESHWATER MOLLUSCS ................... 487 8.1 Introduction ................................................................. 487 8.2 Literature review ......................................................... 488 8.3 The Zambezi River basin ............................................ 489 8.4 The Molluscan fauna .................................................. 491 8.5 Biogeography ............................................................... 508 8.6 Biomphalaria, Bulinis and Schistosomiasis ................ 515 8.7 Conservation ................................................................ 516 8.8 Further investigations .................................................
    [Show full text]
  • Nothobranchius As a Model for Aging Studies. a Review
    Volume 5, Number 2; xxx-xx, April 2014 http://dx.doi.org/10.14336/AD Review Article Nothobranchius as a model for aging studies. A review Alejandro Lucas-Sánchez 1, *, Pedro Francisco Almaida-Pagán 2, Pilar Mendiola 1, Jorge de Costa 1 1 Department of Physiology. Faculty of Biology. University of Murcia. 30100 Murcia, Spain. 2 Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK. [Received October 17, 2013; Revised December 4, 2013; Accepted December 4, 2013] ABSTRACT: In recent decades, the increase in human longevity has made it increasingly important to expand our knowledge on aging. To accomplish this, the use of animal models is essential, with the most common being mouse (phylogenetically similar to humans, and a model with a long life expectancy) and Caenorhabditis elegans (an invertebrate with a short life span, but quite removed from us in evolutionary terms). However, some sort of model is needed to bridge the differences between those mentioned above, achieving a balance between phylogenetic distance and life span. Fish of the genus Nothobranchius were suggested 10 years ago as a possible alternative for the study of the aging process. In the meantime, numerous studies have been conducted at different levels: behavioral (including the study of the rest-activity rhythm), populational, histochemical, biochemical and genetic, among others, with very positive results. This review compiles what we know about Nothobranchius to date, and examines its future prospects as a true alternative to the classic models for studies on aging. Key words: Aging, Fish, killifish, Nothobranchius Aging is a multifactorial process that involves numerous To be considered a model for aging, an animal must mechanisms that operate during the normal life cycle of have a number of features.
    [Show full text]
  • An Age Dependent Mechanism of Mammals Self Destruction
    Ukrainica Bioorganica Acta 1—2 (2004) 3—12 www.bioorganica.org.ua Do mammals die young!? An agedependent mechanism of mammals selfdestruction O. G. Boyko MultiВranched Centre of Science & Technology «Agrobiotech» 50 Kharkivski highway, Kyiv, 02160, Ukraine Abstract. It is hypothesized the first multicellular organisms arisen on the Earth have inherited neither cell aging nor programmed cell death mechanisms from singlecellular ancestors possessing practically unlimited longevity. Both aging and aginginduced death are later evolutionary acquisitions. They are typical only for some phyla, and the majority of nowadays species of multicellular organisms are potentially immortal. Cell aging mechanisms in multicellular organisms can be somewhat involved in agedependent mechanisms of self destruction, but they cannot determine themselves the organism’s aging and longevity. An agerelated mecha nism of mammal selfdestruction appears in the evolutionary lineage from mammallike reptiles Synapsida to mammals in addition to existing systemic and cellular mechanisms of aging. Such agerelated mechanism direct ing the selfdestruction of mammal’s organism is a result of some evolutionary events leading to the «postmitot ic brain» development in mammals. In this minireview, recent results relevant to this hypothesis are surveyed and some approaches to intervening in the proposed process are discussed. Keywords: aging, hypothesis, mammals, birds, exogenous organospecific RNAs, postmitotic brain. Introduction. The ultimate aim of gerontology lachev’s version, potential immortality has alrea researches is to make human aging optional. dy considered not as a luxury, but as a fatal dan Therefore, the initial purpose of this work was ger for population, contrary to initial Weismann’s to consider the most important facts and ideas and conception.
    [Show full text]
  • Ageing Research Reviews Revamping the Evolutionary
    Ageing Research Reviews 55 (2019) 100947 Contents lists available at ScienceDirect Ageing Research Reviews journal homepage: www.elsevier.com/locate/arr Review Revamping the evolutionary theories of aging T ⁎ Adiv A. Johnsona, , Maxim N. Shokhirevb, Boris Shoshitaishvilic a Nikon Instruments, Melville, NY, United States b Razavi Newman Integrative Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, La Jolla, CA, United States c Division of Literatures, Cultures, and Languages, Stanford University, Stanford, CA, United States ARTICLE INFO ABSTRACT Keywords: Radical lifespan disparities exist in the animal kingdom. While the ocean quahog can survive for half a mil- Evolution of aging lennium, the mayfly survives for less than 48 h. The evolutionary theories of aging seek to explain whysuchstark Mutation accumulation longevity differences exist and why a deleterious process like aging evolved. The classical mutation accumu- Antagonistic pleiotropy lation, antagonistic pleiotropy, and disposable soma theories predict that increased extrinsic mortality should Disposable soma select for the evolution of shorter lifespans and vice versa. Most experimental and comparative field studies Lifespan conform to this prediction. Indeed, animals with extreme longevity (e.g., Greenland shark, bowhead whale, giant Extrinsic mortality tortoise, vestimentiferan tubeworms) typically experience minimal predation. However, data from guppies, nematodes, and computational models show that increased extrinsic mortality can sometimes lead to longer evolved lifespans. The existence of theoretically immortal animals that experience extrinsic mortality – like planarian flatworms, panther worms, and hydra – further challenges classical assumptions. Octopuses pose another puzzle by exhibiting short lifespans and an uncanny intelligence, the latter of which is often associated with longevity and reduced extrinsic mortality.
    [Show full text]
  • Clark2019.Pdf (4.792Mb)
    This thesis has been submitted in fulfilment of the requirements for a postgraduate degree (e.g. PhD, MPhil, DClinPsychol) at the University of Edinburgh. Please note the following terms and conditions of use: This work is protected by copyright and other intellectual property rights, which are retained by the thesis author, unless otherwise stated. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author. The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author. When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given. Model Organisms to Models: How Ageing Affects Infectious Disease Dynamics Jessica Clark A thesis submitted for the degree of Doctor of Philosophy The University of Edinburgh 2019 Declaration I declare that this thesis has been composed by myself and that the work has not been submitted for any other degree or professional qualification. I confirm that the work submitted is my own, except where work which has formed part of jointly-authored publications has been included. My contribution and those of the other authors to this work have been explicitly indicated below. I confirm that appropriate credit has been given within this thesis where reference has been made to the work of others. The work presented in Chapter 2 was previously published in Ecology Letters as Disease Spread in Age Structured Populations with Maternal Age Effects by Jessica Clark (Author of Declaration & Student), Jenny Garbutt (Research Group Member), Luke McNally (Collaborator) & Tom Little (Primary Supervisor).
    [Show full text]
  • Jlb Smith Institute of Ichthyology
    ISSN 0075-2088 J.L.B. SMITH INSTITUTE OF ICHTHYOLOGY GRAHAMSTOWN, SOUTH AFRICA SPECIAL PUBLICATION No. 56 SCIENTIFIC AND COMMON NAMES OF SOUTHERN AFRICAN FRESHWATER FISHES by Paul H. Skelton November 1993 SERIAL PUBLICATIONS o f THE J.L.B. SMITH INSTITUTE OF ICHTHYOLOGY The Institute publishes original research on the systematics, zoogeography, ecology, biology and conservation of fishes. Manuscripts on ancillary subjects (aquaculture, fishery biology, historical ichthyology and archaeology pertaining to fishes) will be considered subject to the availability of publication funds. Two series are produced at irregular intervals: the Special Publication series and the Ichthyological Bulletin series. Acceptance of manuscripts for publication is subject to the approval of reviewers from outside the Institute. Priority is given to papers by staff of the Institute, but manuscripts from outside the Institute will be considered if they are pertinent to the work of the Institute. Colour illustrations can be printed at the expense of the author. Publications of the Institute are available by subscription or in exchange for publi­ cations of other institutions. Lists of the Institute’s publications are available from the Publications Secretary at the address below. INSTRUCTIONS TO AUTHORS Manuscripts shorter than 30 pages will generally be published in the Special Publications series; longer papers will be considered for the Ichthyological Bulletin series. Please follow the layout and format of a recent Bulletin or Special Publication. Manuscripts must be submitted in duplicate to the Editor, J.L.B. Smith Institute of Ichthyology, Private Bag 1015, Grahamstown 6140, South Africa. The typescript must be double-spaced throughout with 25 mm margins all round.
    [Show full text]
  • ER Galimov1, JN Lohr1, and D. Gems1,A
    MINI-REVIEW When and How Can Death Be an Adaptation? E. R. Galimov1, J. N. Lohr1, and D. Gems1,a* 1Institute of Healthy Ageing, Research Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK ae-mail: david.gems@ucl.ac.uk * To whom correspondence should be addressed. Abstract—The concept of phenoptosis (or programmed organismal death) is problematic with respect to most species (including humans) since it implies that dying of old age is an adaptation, which contradicts the established evolutionary theory. But can dying ever be a strategy to promote fitness? Given recent developments in our understanding of the evolution of altruism, particularly kin and multilevel selection theories, it is timely to revisit the possible existence of adaptive death. Here, we discuss how programmed death could be an adaptive trait under certain conditions found in organisms capable of clonal colonial existence, such as the budding yeast Saccharomyces cerevisiae and, perhaps, the nematode Caenorhabditis elegans. The concept of phenoptosis is only tenable if consistent with the evolutionary theory; this accepted, phenoptosis may only occur under special conditions that do not apply to most animal groups (including mammals). DOI: 10.1134/S000629791912001? Keywords: adaptive death, aging, altruism, C. elegans, evolution, inclusive fitness PROGRAMMED AGING AND PHENOPTOSIS Is aging programmed? Asking this question risks falling afoul of the old warning: ask a stupid question and you’ll get a stupid answer [1, 2]. This is because the term programmed aging has multiple meanings, which can lead the questioner into logical confusion [3]. But it is possible to disambiguate this term and to avoid conceptual pratfalls, as follows.
    [Show full text]
  • Draft Risk Assessment Report Nothobranchius Furzeri (Turquoise
    APPLICATION TO AMEND THE LIST OF SPECIMENS SUITABLE FOR LIVE IMPORT Draft Risk Assessment Report 1. Taxonomy of the species a. Family name: Aplocheilidae b. Genus name: Nothobranchius c. Species: N. furzeri d. Subspecies: No e. Taxonomic Reference: http://www.uniprot.org/taxonomy/105023 f. Common Names: Turquoise killifish g. Is the species a genetically-modified organism (GMO)? No 2. Status of the species under CITES Species is not listed in the CITES Appendices. 3. Ecology of the species a. Longevity: what is the average lifespan of the species in the wild and in captivity? The average lifespan of the species in captivity is 13 weeks (1). Wild derived N. furzeri from three different habitats showed a maximum lifespan of 25-32 weeks (1). b. What is the maximum length and weight that the species attains? Provide information on the size and weight range for males and females of the species. As per the original formal description of the species, the standard length of N. furzeri from a wild population ranged from 2.5cm to 4.4cm (2). The maximum length the species can attain is 7cm (3). The mean maximal body weight reported for males is 3.8 ± 1.1 g (range: 0.5 – 6.7 g) and 2.2 ± 0.6 g (range: 0.2 - 3.6 g) for females (4). Growth rates of Nothobranchius in the wild have been reported to be similar to those in captivity (5). c. Discuss the identification of the individuals in this species, including if the sexes of the species are readily distinguishable, and if the species is difficult to distinguish from other species.
    [Show full text]