DOCSLIB.ORG

Two-Phase Increase in the Maximum Size of Life Over 3.5 Billion Years Reflects Biological Innovation and Environmental Opportunity

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Two-Phase Increase in the Maximum Size of Life Over 3.5 Billion Years Reflects Biological Innovation and Environmental Opportunity Two-phase increase in the maximum size of life over 3.5 billion years reflects biological innovation and environmental opportunity Jonathan L. Paynea,1, Alison G. Boyerb, James H. Brownb, Seth Finnegana, Michał Kowalewskic, Richard A. Krause, Jr.d, S. Kathleen Lyonse, Craig R. McClainf, Daniel W. McSheag, Philip M. Novack-Gottshallh, Felisa A. Smithb, Jennifer A. Stempieni, and Steve C. Wangj aDepartment of Geological and Environmental Sciences, Stanford University, 450 Serra Mall, Building 320, Stanford, CA 94305; bDepartment of Biology, University of New Mexico, Albuquerque, NM 87131; cDepartment of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; dMuseum fu¨r Naturkunde der Humboldt–Universita¨t zu Berlin, D-10115, Berlin, Germany; eDepartment of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560; fMonterey Bay Aquarium Research Institute, Moss Landing, CA 95039; gDepartment of Biology, Box 90338, Duke University, Durham, NC 27708; hDepartment of Geosciences, University of West Georgia, Carrollton, GA 30118; iDepartment of Geological Sciences, University of Colorado, Boulder, CO 80309; and jDepartment of Mathematics and Statistics, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081 Edited by James W. Valentine, University of California, Berkeley, CA, and approved November 14, 2008 (received for review July 1, 2008) The maximum size of organisms has increased enormously since and avoids the more substantial empirical difficulties in deter- the initial appearance of life >3.5 billion years ago (Gya), but the mining mean, median, or minimum size for all life or even for pattern and timing of this size increase is poorly known. Conse- many individual taxa. For each era within the Archean Eon quently, controls underlying the size spectrum of the global biota (4,000–2,500 Mya) and for each period within the Proterozoic have been difficult to evaluate. Our period-level compilation of the (2,500–542 Mya) and Phanerozoic (542–0 Mya) eons, we ob- largest known fossil organisms demonstrates that maximum size tained the sizes of the largest known fossil prokaryotes, single- increased by 16 orders of magnitude since life first appeared in the celled eukaryotes, metazoans, and vascular plants by reviewing fossil record. The great majority of the increase is accounted for by the published literature and contacting taxonomic experts. Sizes 2 discrete steps of approximately equal magnitude: the first in the were converted to volume to facilitate comparisons across middle of the Paleoproterozoic Era (Ϸ1.9 Gya) and the second disparate taxonomic groups (see Data and Methods). The data- during the late Neoproterozoic and early Paleozoic eras (0.6–0.45 base is deposited in Data Dryad (www.datadryad.org) and can Gya). Each size step required a major innovation in organismal be accessed at http://hdl.handle.net/10255/dryad.222. complexity—first the eukaryotic cell and later eukaryotic multicel- lularity. These size steps coincide with, or slightly postdate, in- Results creases in the concentration of atmospheric oxygen, suggesting The maximum body volume of organisms preserved in the fossil latent evolutionary potential was realized soon after environmen- record has increased by Ϸ16 orders of magnitude over the last tal limitations were removed. 3.5 billion years (Fig. 1). Increase in maximum size occurred episodically, with pronounced jumps of approximately 6 orders body size ͉ Cambrian ͉ oxygen ͉ Precambrian ͉ trend of magnitude in the mid-Paleoproterozoic (Ϸ1.9 Gya) and during the Ediacaran through Ordovician (600–450 Mya). Thus, espite widespread scientific and popular fascination with Ϸ75% of the overall increase in maximum body size over Dthe largest and smallest organisms and numerous studies of geological time took place during 2 geologically brief intervals body size evolution within individual taxonomic groups (1–9), that together comprise Ͻ20% of the total duration of life on the first-order pattern of body size evolution through the history Earth. of life has not been quantified rigorously. Because size influences Paleoproterozoic size increase occurs as a single step in Fig. (and may be limited by) a broad spectrum of physiological, 1, reflecting the presence of Grypania spiralis in the Paleopro- ecological, and evolutionary processes (10–16), detailed docu- terozoic (Orosirian) Negaunee Iron Formation of Canada (19). mentation of size trends may shed light on the constraints and The taxonomic affinities of these fossils are controversial: Their innovations that have shaped life’s size spectrum over evolu- morphological regularity and size suggest they are the remains of tionary time as well as the role of the body size spectrum in eukaryotic organisms (19, 20), but they have also been inter- structuring global ecosystems. Bonner (17) presented a figure preted as composite microbial filaments (21). Possible trace portraying a gradual, monotonic increase in the overall maxi- fossils of similar age and comparable size occur in the Stirling mum size of living organisms over the past 3.5 billion years. The Quartzite of Australia and the Chorhat Sandstone of India, pattern appears consistent with a simple, continuous underlying suggesting Orosirian size increase may not have been confined process such as diffusion (18), but could also reflect a more to Grypania (22, 23). Slightly younger specimens of similar sizes complex process. Bonner, for example, proposed that lineages from the Changzhougou and Changlinggou formations of China evolve toward larger sizes to exploit unoccupied ecological niches. For decades, Bonner’s has been the only attempt to quantify body size evolution over the entire history of life on Author contributions: J.L.P., A.G.B., J.H.B., S.F., M.K., R.A.K., S.K.L., C.R.M., D.W.M., Earth, but the data he presented were not tied to particular fossil P.M.N.-G., F.A.S., J.A.S., and S.C.W. designed research, performed research, analyzed data, specimens and were plotted without consistent controls on and wrote the paper. taxonomic scale against a nonlinear timescale. Hence, we have The authors declare no conflict of interest. lacked sufficient data on the tempo and mode of maximum size This article is a PNAS Direct Submission. change to evaluate potential first-order biotic and abiotic con- Freely available online through the PNAS open access option. trols on organism size through the history of life. 1To whom correspondence should be addressed. E-mail: [email protected]. Here, we document the evolutionary history of body size on This article contains supporting information online at www.pnas.org/cgi/content/full/ Earth, focusing on the upper limit to size. Use of maximum size 0806314106/DCSupplemental. allows us to assess constraints on the evolution of large body size © 2008 by The National Academy of Sciences of the USA 24–27 ͉ PNAS ͉ January 6, 2009 ͉ vol. 106 ͉ no. 1 www.pnas.org͞cgi͞doi͞10.1073͞pnas.0806314106 Downloaded by guest on September 29, 2021 history of maximum size at the taxonomic and temporal scales giant 14 14 addressed. Larger fossils and larger fossil species tend to be pO2 < 0.1% PAL pO2 1%-10% PAL pO2 ~ 100% PAL sequioa 12 remarked upon in the paleontological literature; genus and blue species names with roots meaning ‘‘large’’ or ‘‘giant’’ are com- cephalopod 10 10 whale monly applied to particularly sizeable taxa, making them easy to 8 arthropod ) identify in the literature. Because we treat size data on a 3 Dickinsonia 6 largest 6 single-celled logarithmic scale, even moderate sampling biases are unlikely to eukaryote 4 cause observed maxima to vary by Ͼ1 or 2 orders of magnitude. Grypania Ͼ 2 2 In contrast, species in the maximum size dataset span 16 orders of magnitude, and the sizes of all living organisms span Ͼ22 0 largest prokaryote orders of magnitude (27). Although the upper bound error bars -2 -2 for the individual data points cannot be readily estimated, these Biovolume (log mm Biovolume -4 errors are likely to be negligible given the size range addressed Primaevifilum -6 -6 in our study. For example, it is unlikely that dinosaurs, whales, Ͼ -8 or cephalopods 10 times the size of the largest known speci- EoarchaeanPaleoar. Mesoar. Neoar. Paleoproterozoic Mesoprot. Neoprot. Pz. Mz. C Archaean Proterozoic Phan. mens have ever existed. That the largest living plant and animal 4000 3000 2000 1000 species are not much bigger than the largest known fossils (Fig. Age (Ma) 1) suggests fossils reliably sample not only trends but also absolute values of maximum size at the temporal and taxonomic Fig. 1. Sizes of the largest fossils through Earth history. Size maxima are scales considered in this study. Trends in trace fossil sizes are illustrated separately for single-celled eukaryotes, animals, and vascular plants for the Ediacaran and Phanerozoic. The solid line denotes the trend in generally concordant with the body fossil record (28), indicating the overall maximum for all of life. Increases in the overall maximum occurred that the apparent size increase from the Ediacaran through in discrete steps approximately corresponding to increases in atmospheric Ordovician does not merely reflect an increase in preservation oxygen levels in the mid-Paleoproterozoic and Ediacaran–Cambrian–early potential of large animals. Moreover, large-bodied fossils occur Ordovician. Sizes of the largest fossil prokaryotes were not compiled past 1.9 in both well-fossilized clades (e.g., cephalopods) and taxa that Gya. Estimates
Load more

Recommended publications
  • Size Limits of Very Small Microorganisms
    Size Limits of Very Small Microorganisms Proceedings of a Workshop Steering Group for the Workshop on Size Limits of Very Small Microorganisms Space Studies Board Commission on Physical Sciences, Mathematics, and Applications National Research Council NATIONAL ACADEMY PRESS Washington, D.C. NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the steering group responsible for the report were chosen for their special competences and with regard for appropriate balance. The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers.
    [Show full text]
  • Animal Body Size
    introduction On Being the Right Size: The Impor tance of Size in Life History, Ecology, and Evolution Felisa A. Smith and S. Kathleen Lyons “For every type of animal there is an optimum size.” —J. B. S. Haldane, “On Being the Right Size” iving things vary enormously in body size. Across the spectrum of Llife, the size of animals spans more than twenty-one orders of mag- nitude, from the smallest (mycoplasm) at ∼10 –13 g to the largest (blue whale) at 108 g (fi g. I.1, table I.1). We now know that much of this range was achieved in two “jumps” corresponding to the evolution of eukary- otes and metazoans, at 2.1 Ga and 640 Ma, respectively (Payne et al. 2009). Yet the drivers behind these jumps, the factors underlying similar- ities and differences in body size distributions, and the factors selecting for the “characteristic” or “optimum” size of organisms remain unre- solved (Smith et al. 2004; Storch and Gaston 2004). The study of body size has a long history in scientifi c discourse. Some of our earliest scientifi c treatises speculate on the factors underlying the body mass of organisms (e.g., Aristotle 347–334 B.C.). Many other emi- nent scientists and philosophers, including Galileo Galilei, Charles Dar- win, J. B. S. Haldane, George Gaylord Simpson, and D’Arcy Thompson, have also considered why organisms are the size they are and the con- sequences of larger or smaller size. As Galileo stated, “Nature cannot produce a horse as large as twenty ordinary horses or a giant ten times taller than an ordinary man unless by miracle or by greatly altering the proportions of his limbs and especially of his bones” (Galileo 1638).
    [Show full text]
  • The Ocean Biosphere: from Microbes to Mammals
    Keywords: biosphere, bioaccumulate, biodiversity, food web, ecology, abiotic factors, and biotic factors. Lesson II: The Ocean Biosphere: From Microbes to Mammals Planet Earth is truly a water environments is called ecology. planet! We have a connection to all Living things such as plants and living things in the ocean, from the animals in the environment are called microscopic floating plants that biotic factors, or biota. Nonliving supply us with the oxygen we breathe, things in the environment, such as to the huge blue whale that fills its soil, water, temperature, light, belly with a ton of krill. This circle of salinity, chemical composition, and life is called a biosphere. The earth’s currents are abiotic factors. biosphere is composed of all living Together, these factors interact and things, from the deepest oceans to the function as an ecosystem. An upper atmosphere. It includes all the ecosystem is a community of different air, land and water where life exists. organisms interacting with the abiotic All living things depend upon and parts of its environment. Ecosystems interact with each other and with the may be as small as a beehive, or as non-living things in their large as the Atlantic Ocean. With the environment. aid of technology, we are discovering The study of interactions entire new ecosystems that survive in between organisms and their our biosphere. Our Ocean Biosphere Look at an atlas of the world animals. A few abiotic factors are and identify one of the major oceans temperature, salinity, pressure, found on planet earth. In short, the dissolved gases and depth.
    [Show full text]
  • Microbial Cooking, Cleaning, and Control Under Stress
    life Review Housekeeping in the Hydrosphere: Microbial Cooking, Cleaning, and Control under Stress Bopaiah Biddanda 1,* , Deborah Dila 2 , Anthony Weinke 1 , Jasmine Mancuso 1 , Manuel Villar-Argaiz 3 , Juan Manuel Medina-Sánchez 3 , Juan Manuel González-Olalla 4 and Presentación Carrillo 4 1 Annis Water Resources Institute, Grand Valley State University, Muskegon, MI 49441, USA; [email protected] (A.W.); [email protected] (J.M.) 2 School of Freshwater Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53204, USA; [email protected] 3 Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain; [email protected] (M.V.-A.); [email protected] (J.M.M.-S.) 4 Instituto Universitario de Investigación del Agua, Universidad de Granada, 18071 Granada, Spain; [email protected] (J.M.G.-O.); [email protected] (P.C.) * Correspondence: [email protected]; Tel.: +1-616-331-3978 Abstract: Who’s cooking, who’s cleaning, and who’s got the remote control within the waters blan- keting Earth? Anatomically tiny, numerically dominant microbes are the crucial “homemakers” of the watery household. Phytoplankton’s culinary abilities enable them to create food by absorbing sunlight to fix carbon and release oxygen, making microbial autotrophs top-chefs in the aquatic kitchen. However, they are not the only bioengineers that balance this complex household. Ubiqui- tous heterotrophic microbes including prokaryotic bacteria and archaea (both “bacteria” henceforth), Citation: Biddanda, B.; Dila, D.; eukaryotic protists, and viruses, recycle organic matter and make inorganic nutrients available to Weinke, A.; Mancuso, J.; Villar-Argaiz, primary producers. Grazing protists compete with viruses for bacterial biomass, whereas mixotrophic M.; Medina-Sánchez, J.M.; protists produce new organic matter as well as consume microbial biomass.
    [Show full text]
  • Viral Genetic Evolution in Host Cells Supports Tumorigenesis
    Short Communication Adv Res Gastroentero Hepatol Volume 4 Issue 2 - March 2017 DOI: 10.19080/ARGH.2017.03.555631 Copyright © All rights are reserved by Daniel A Achinko Viral Genetic Evolution in Host Cells Supports Tumorigenesis Daniel A Achinko* University City Science Center, USA Submission: March 01, 2017; Published: March 23, 2017 *Corresponding author: Daniel A Achinko, University City Science Center, PepVax, Inc.10411 Motor City Drive Bethesda, MD 20817, Immage Biotherapeutics Corp, 3711 Market St. 8th Floor, Philadelphia, PA 19104, USA, Email: Abstract Cancer genetics now associates several virus types to the disease. Six main viruses are considered underlying pathogenic agents of cancer and more of them are DNA viruses while a few are RNA retroviruses. The role of viruses in cancer is still elusive though several host cell genetic are different in the type of genetic material they carry but what makes them common to severe disease situations could be their ability to integrateexpression host patterns, genome, regulatory hence exploiting mechanisms the host and transcription genetic variations and translation have been factors identified to drive and theirassociated replication with relatedand encapsulation viral activity. of Virusesgenetic to immune target cells could be of therapeutic importance if these mechanisms are well understood. information for delivery out of the cell. The variation of these viruses in different cancer types and their evolutionary history with specificity Background until experimental analysis was able to show that, a virus was Viruses are considered the smallest organisms and known to bemetabolically inert out of a host cell but become active when they integrate and infect a host cell in order to reproduce.
    [Show full text]
  • NECR252 Edition 1 Development of DNA Applications in Natural
    Natural England Commissioned Report NECR252 Development of DNA applications in Natural England 2016/2017 First published August 2018 www.gov.uk/natural-england Foreword Natural England commission a range of reports from external contractors to provide evidence and advice to assist us in delivering our duties. The views in this report are those of the authors and do not necessarily represent those of Natural England. Background DNA based applications have the potential to There are still significant limitations to the use of significantly change how we monitor this technology in others areas and in 2016/17 biodiversity and which species and taxa we Natural England worked with NatureMetrics on a monitor. These techniques may provide number of exploratory projects looking at species cheaper alternatives to existing species detection in standing freshwaters, saline lagoons, monitoring, an ability to detect species that we coastal waters and sediments, terrestrial do not currently monitor effectively and the invertebrate traps, deadwood mould, vegetation potential to develop new measures of habitat and soils. This report presents the results from and ecosystem quality. those projects. Natural England has been supporting the This report should be cited as: development of DNA techniques for a number TANG, C.Q., CRAMPTON-PLATT, A., of years. The use of environmental DNA TOWNEND, S., BRUCE, K., BISTA, I. & CREER, (eDNA) to determine the presence or absence S. 2018. Development of DNA applications in of great crested newts in ponds is now a Natural
    [Show full text]
  • Life: Complexity and Diversity 3
    SERIES I ARTICLE Life: Complexity and Diversity 3. Growing Larger Madhav Gadgil Living organisms continually evolve to occupy newer envi­ ronmental regimes. In the process they develop more complex structures and grow to larger sizes. They also evolve more intricate ways of relating to each other. The larger, more complex organisms do not replace the simpler, smaller ones, rather they come to coexist with them in increasingly complex ecosystems. This promotes a con­ Madhav Gadgil is with the Centre for Ecological tinual increase in the diversity of life over evolutionary time. Scienc'es, Indian Institute of Science and Jawaharlal Ways of Life Nehru Centre for Advanced Scientific Research, Bangalore. Decomposing, photosynthesizing and feeding on other organ­ His fascination for the isms are three broad ways of organizing fluxes of energy necessary diversity of life has for the maintenance and propagation of all life (Figure 1). But prompted him to study a whole range of life forms from paper wasps to anchovies, mynas to elephants, goldenrods to bamboos. Figure 1 Decomposition/ or living off preformed or­ ganic molecules is the old­ est way of life and is still at the centre of both te"es­ trial and aquatic food webs. Autotrophy, or manufacture of organic molecules through photosynthesis came next; followed later by heterotrophy or feeding on other living organisms giving rise to the elaborate food webs of present day ecosystems. _________ ~AAA~~______ __ RESONANCE I April 1996 ~"V V VV V v~ 15 SERIES I ARTICLE As living organisms living organisms have created an infinity of variations around have adopted these these themes.
    [Show full text]
  • A) Species of Organisms Found on Earth Today Have Adaptations Not
    1. The theory of biological evolution includes which 5. The changes in foot structure in a bird population over concepts? many generations are shown in the diagram below. A) species of organisms found on Earth today have adaptations not always found in earlier species B) fossils are the remains of present-day species and were all formed at the same time C) individuals may acquire physical characteristics after birth and pass these acquired characteristics on to their offspring. These changes can best be explained by the concept D) the smallest organisms are always eliminated by of the larger organisms within the ecosystem A) evolution 2. Some behaviors such as mating and caring for young B) extinction are genetically determined in certain species of birds. The presence of these behaviors is most likely due to C) stable gene frequencies the fact that D) use and disuse A) birds do not have the ability to learn 6. The diversity of organisms present on Earth is the B) individual birds need to learn to survive and result of reproduce A) ecosystem stability B) homeostasis C) these behaviors helped birds to survive in the C) natural selection D) direct harvesting past 7. Most species on Earth have changed through time. D) within their lifetimes, birds developed these This change is known as behaviors A) isolation B) geology 3. In order for a species to evolve, it must be able to C) ecology D) evolution A) consume a large quantity of food 8. A species of bird known as Bird of Paradise has been B) reproduce successfully observed in the jungles of New Guinea.
    [Show full text]
  • Arctic Food Webs – Teacher
    Life Under the Ice Unit II: Sea Ice Ecology Arctic Food Webs ACTIVITY TIME 40-50 minutes LEARNING OUTCOMES • Discuss roles of primary producers and consum- ers in a food web. • Describe food web interac- tions specific to the arctic sea ice. • Illustrate an arctic marine food web. OVERVIEW In this activity students work in groups to develop an arctic marine food web. Groups then move through the classroom viewing each others’ food webs and adding their own information. FLOW 1. Watch video & explore 4. Graffiti activity with food webs. Interactive Food Web. 5. Interpretation of student food 2. Brainstorm a list of marine webs. arctic organisms. 6. Discussion questions. 3. Student groups create food webs. ArcticSeaIce.com THE ARCTIC SEA ICE EDUCATIONAL PACKAGE TEACHER VERSION 1 Arctic Food Webs D CONTENTS Student Overview 2 Discussion Questions 9 Background 3 Extensions 11 Preparation 6 Sources 11 Procedure 7 Attribution 11 STUDENT OVERVIEW WHY? HOW? Food webs help us understand the interconnected nature of ecosystems. They help Watch a video showing numerous us understand human’s place in ecosystems. play-circle sea ice organisms WHAT? Learn the Inuktitut names and leaf Inuit knowledge species • The organisms that live in a sea ice ecosystem. In groups, choose a species to • The predator and prey relationships paw focus on between these species. Create a food web Talk about your findings and make connections Image 1 Narwal swim through a lead in the sea ice. 2 TEACHER VERSION THE ARCTIC SEA ICE EDUCATIONAL PACKAGE ArcticSeaIce.com Life Under the Ice Unit II: Sea Ice Ecology BACKGROUND VOCABULARY abiotic: Non-living ele- “Cree and Inuit observe and respect a natural order of relationships ments of an ecosystem, connecting the largest animals to the smallest organisms.
    [Show full text]
  • Protists Are Microbes Too: a Perspective
    The ISME Journal (2009) 3, 4–12 & 2009 International Society for Microbial Ecology All rights reserved 1751-7362/09 $32.00 www.nature.com/ismej PERSPECTIVE Protists are microbes too: a perspective David A Caron1, Alexandra Z Worden2, Peter D Countway1, Elif Demir2 and Karla B Heidelberg1 1Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA and 2Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA Our understanding of the composition and activities of microbial communities from diverse habitats on our planet has improved enormously during the past decade, spurred on largely by advances in molecular biology. Much of this research has focused on the bacteria, and to a lesser extent on the archaea and viruses, because of the relative ease with which these assemblages can be analyzed and studied genetically. In contrast, single-celled, eukaryotic microbes (the protists) have received much less attention, to the point where one might question if they have somehow been demoted from the position of environmentally important taxa. In this paper, we draw attention to this situation and explore several possible (some admittedly lighthearted) explanations for why these remarkable and diverse microbes have remained largely overlooked in the present ‘era of the microbe’. The ISME Journal (2009) 3, 4–12; doi:10.1038/ismej.2008.101; published online 13 November 2008 Keywords: protists; eukaryotic genomics; species concept; diversity; biogeography Introduction research activity has lagged behind that of other microbes despite their rather impressive contribu- Environmental science has clearly entered the ‘era tions to microbiological history, microbial diversity of the microbe’ during the past decade.
    [Show full text]
  • Body Size Evolution Across the Geozoic
    EA44CH20-Smith ARI 4 May 2016 14:25 V I E E W R S I E N C N A D V A Body Size Evolution Across the Geozoic 1, 2 2 Felisa A. Smith, ∗ Jonathan L. Payne, Noel A. Heim, Meghan A. Balk,1 Seth Finnegan,3 MichałKowalewski,4 S. Kathleen Lyons,5 Craig R. McClain,6 Daniel W. McShea,7 Philip M. Novack-Gottshall,8 Paula Spaeth Anich,9 and Steve C. Wang10 1Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131; email: [email protected] 2Department of Geological Sciences, Stanford University, Stanford, California 94305 3Department of Integrative Biology, University of California, Berkeley, California 94720 4Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611 5Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560 6National Evolutionary Synthesis Center, Durham, North Carolina 27705 7Department of Biology, Duke University, Durham, North Carolina 27708 8Department of Biological Sciences, Benedictine University, Lisle, Illinois 60532 9Department of Biology and Natural Resources, Northland College, Ashland, Wisconsin 54806 10Department of Mathematics and Statistics, Swarthmore College, Swarthmore, Pennsylvania 19081 Annu. Rev. Earth Planet. Sci. 2016. 44:523–53 Keywords The Annual Review of Earth and Planetary Sciences is allometry, biovolume, maximum body size, macroevolution, geobiology online at earth.annualreviews.org This article’s doi: Abstract 10.1146/annurev-earth-060115-012147 The Geozoic encompasses the 3.6 Ga interval in Earth history when life has Copyright c 2016 by Annual Reviews. ⃝ existed. Over this time, life has diversified from exclusively tiny, single-celled All rights reserved organisms to include large, complex multicellular forms.
    [Show full text]
  • The Evolution of Monogenean Diversity
    International Journal for Parasitology 32 (2002) 245–254 www.parasitology-online.com Invited review The evolution of monogenean diversity Robert Poulin* Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand Received 10 April 2001; received in revised form 10 September 2001; accepted 28 September 2001 Abstract The Monogenea are an ideal group for investigations of the processes behind their past diversification and their present diversity for at least three reasons: they are diverse both in terms of morphology and numbers, they are generally host specific, and their phylogeny is well resolved, at least to the family level. The present investigation takes a broad look at monogenean diversity in order to try to determine whether the diversification of monogeneans is driven by some ecological features of the parasites themselves, or by extrinsic factors associated with their hosts. First, our current knowledge of monogenean diversity appears good enough to warrant investigation into its evolution. The body size of new species correlates negatively with their year of description both generally and within given families, i.e. it decreases over time in a way that suggests that only some of the smallest species are left to be discovered. Second, the occurrence of congeneric monogenean species on the same host species is not associated with host body size, once phylogenetic influences are controlled. This analysis suggests that host size is not one of the factors promoting local diversification of monogenean taxa. Third, the species richness of the different monogenean families does not correlate with the average body size of their members.
    [Show full text]