Geologic Time Scale
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
The Eocene Arctic Azolla Bloom: Environmental Conditions, Productivity and Carbon Drawdown
Geobiology (2009), 7, 155–170 DOI: 10.1111/j.1472-4669.2009.00195.x TheBlackwell Publishing Ltd Eocene Arctic Azolla bloom: environmental conditions, productivity and carbon drawdown E. N. SPEELMAN,1 M. M. L. VAN KEMPEN,2 J. BARKE,3 H. BRINKHUIS,3 G. J. REICHART,1 A. J. P. SMOLDERS,2 J. G. M. ROELOFS,2 F. SANGIORGI,3 J. W. DE LEEUW,1,3,4 A. F. LOTTER3 AND J. S. SINNINGHE DAMSTÉ1,4 1Faculty of Geosciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands 2Department of Aquatic Ecology and Environmental Biology, Faculty of Science, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands 3Institute of Environmental Biology, Laboratory of Palaeobotany and Palynology, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands 4NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands ABSTRACT Enormous quantities of the free-floating freshwater fern Azolla grew and reproduced in situ in the Arctic Ocean during the middle Eocene, as was demonstrated by microscopic analysis of microlaminated sediments recovered from the Lomonosov Ridge during Integrated Ocean Drilling Program (IODP) Expedition 302. The timing of the Azolla phase (~48.5 Ma) coincides with the earliest signs of onset of the transition from a greenhouse towards the modern icehouse Earth. The sustained growth of Azolla, currently ranking among the fastest growing plants on Earth, in a major anoxic oceanic basin may have contributed to decreasing atmospheric pCO2 levels via burial of Azolla-derived organic matter. The consequences of these enormous Azolla blooms for regional and global nutrient and carbon cycles are still largely unknown. -
Lineages, Splits and Divergence Challenge Whether the Terms Anagenesis and Cladogenesis Are Necessary
Biological Journal of the Linnean Society, 2015, , – . With 2 figures. Lineages, splits and divergence challenge whether the terms anagenesis and cladogenesis are necessary FELIX VAUX*, STEVEN A. TREWICK and MARY MORGAN-RICHARDS Ecology Group, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand Received 3 June 2015; revised 22 July 2015; accepted for publication 22 July 2015 Using the framework of evolutionary lineages to separate the process of evolution and classification of species, we observe that ‘anagenesis’ and ‘cladogenesis’ are unnecessary terms. The terms have changed significantly in meaning over time, and current usage is inconsistent and vague across many different disciplines. The most popular definition of cladogenesis is the splitting of evolutionary lineages (cessation of gene flow), whereas anagenesis is evolutionary change between splits. Cladogenesis (and lineage-splitting) is also regularly made synonymous with speciation. This definition is misleading as lineage-splitting is prolific during evolution and because palaeontological studies provide no direct estimate of gene flow. The terms also fail to incorporate speciation without being arbitrary or relative, and the focus upon lineage-splitting ignores the importance of divergence, hybridization, extinction and informative value (i.e. what is helpful to describe as a taxon) for species classification. We conclude and demonstrate that evolution and species diversity can be considered with greater clarity using simpler, more transparent terms than anagenesis and cladogenesis. Describing evolution and taxonomic classification can be straightforward, and there is no need to ‘make words mean so many different things’. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 00, 000–000. -
A Framework for Post-Phylogenetic Systematics
A FRAMEWORK FOR POST-PHYLOGENETIC SYSTEMATICS Richard H. Zander Zetetic Publications, St. Louis Richard H. Zander Missouri Botanical Garden P.O. Box 299 St. Louis, MO 63166 [email protected] Zetetic Publications in St. Louis produces but does not sell this book. Any book dealer can obtain a copy for you through the usual channels. Resellers please contact CreateSpace Independent Publishing Platform of Amazon. ISBN-13: 978-1492220404 ISBN-10: 149222040X © Copyright 2013, all rights reserved. The image on the cover and title page is a stylized dendrogram of paraphyly (see Plate 1.1). This is, in macroevolutionary terms, an ancestral taxon of two (or more) species or of molecular strains of one taxon giving rise to a descendant taxon (unconnected comma) from one ancestral branch. The image on the back cover is a stylized dendrogram of two, genus-level speciational bursts or dis- silience. Here, the dissilient genus is the basic evolutionary unit (see Plate 13.1). This evolutionary model is evident in analysis of the moss Didymodon (Chapter 8) through superoptimization. A super- generative core species with a set of radiative, specialized descendant species in the stylized tree com- promises one genus. In this exemplary image; another genus of similar complexity is generated by the core supergenerative species of the first. TABLE OF CONTENTS Preface..................................................................................................................................................... 1 Acknowledgments.................................................................................................................................. -
Assessing Symbiont Extinction Risk Using Cophylogenetic Data 2 3 Jorge Doña1 and Kevin P
1 Assessing symbiont extinction risk using cophylogenetic data 2 3 Jorge Doña1 and Kevin P. Johnson1 4 5 1. Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, 6 1816 S. Oak St., Champaign, IL 61820, USA 7 8 *Corresponding authors: Jorge Doña & Kevin Johnson; e-mail: [email protected] & [email protected] 9 10 Abstract: Symbionts have a unique mode of life that has attracted the attention of ecologists and 11 evolutionary biologists for centuries. As a result of this attention, these disciplines have produced 12 a mature body of literature on host-symbiont interactions. In contrast, the discipline of symbiont 13 conservation is still in a foundational stage. Here, we aim to integrate methodologies on symbiont 14 coevolutionary biology with the perspective of conservation. We focus on host-symbiont 15 cophylogenies, because they have been widely used to study symbiont diversification history and 16 contain information on symbiont extinction. However, cophylogenetic information has never been 17 used nor adapted to the perspective of conservation. Here, we propose a new statistic, 18 “cophylogenetic extinction rate” (Ec), based on coevolutionary knowledge, that uses data from 19 event-based cophylogenetic analyses, and which could be informative to assess relative symbiont 20 extinction risks. Finally, we propose potential future research to further develop estimation of 21 symbiont extinction risk from cophylogenetic analyses and continue the integration of this existing 22 knowledge of coevolutionary biology and cophylogenetics into future symbiont conservation 23 studies and practices. 24 25 Keywords: coevolution, coextinction risk, conservation biology, cophylogenies, host-symbiont 26 interactions, parasites. -
Approaches to Macroevolution: 2. Sorting of Variation, Some Overarching Issues, and General Conclusions
Evol Biol (2017) 44:451–475 DOI 10.1007/s11692-017-9434-7 SYNTHESIS PAPER Approaches to Macroevolution: 2. Sorting of Variation, Some Overarching Issues, and General Conclusions David Jablonski1 Received: 31 August 2017 / Accepted: 4 October 2017 / Published online: 24 October 2017 © The Author(s) 2017. This article is an open access publication Abstract Approaches to macroevolution require integra- edges of apparent trends. Biotic interactions can have nega- tion of its two fundamental components, within a hierarchi- tive or positive effects on taxonomic diversity within a clade, cal framework. Following a companion paper on the origin but cannot be readily extrapolated from the nature of such of variation, I here discuss sorting within an evolutionary interactions at the organismic level. The relationships among hierarchy. Species sorting—sometimes termed species selec- macroevolutionary currencies through time (taxonomic rich- tion in the broad sense, meaning differential origination and ness, morphologic disparity, functional variety) are crucial extinction owing to intrinsic biological properties—can be for understanding the nature of evolutionary diversification. split into strict-sense species selection, in which rate differ- A novel approach to diversity-disparity analysis shows that entials are governed by emergent, species-level traits such as taxonomic diversifications can lag behind, occur in concert geographic range size, and effect macroevolution, in which with, or precede, increases in disparity. Some overarching rates are governed by organism-level traits such as body issues relating to both the origin and sorting of clades and size; both processes can create hitchhiking effects, indirectly phenotypes include the macroevolutionary role of mass causing the proliferation or decline of other traits. -
Can Darwin's Finches and Their Native Ectoparasites Survive the Control of Th
Insect Conservation and Diversity (2017) 10, 193–199 doi: 10.1111/icad.12219 FORUM & POLICY Coextinction dilemma in the Galapagos Islands: Can Darwin’s finches and their native ectoparasites survive the control of the introduced fly Philornis downsi? 1 2 MARIANA BULGARELLA and RICARDO L. PALMA 1School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand and 2Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand Abstract. 1. The survival of parasites is threatened directly by environmental alter- ation and indirectly by all the threats acting upon their hosts, facing coextinction. 2. The fate of Darwin’s finches and their native ectoparasites in the Galapagos Islands is uncertain because of an introduced avian parasitic fly, Philornis downsi, which could potentially drive them to extinction. 3. We documented all known native ectoparasites of Darwin’s finches. Thir- teen species have been found: nine feather mites, three feather lice and one nest mite. No ticks or fleas have been recorded from them yet. 4. Management options being considered to control P. downsi include the use of the insecticide permethrin in bird nests which would not only kill the invasive fly larvae but the birds’ native ectoparasites too. 5. Parasites should be targeted for conservation in a manner equal to that of their hosts. We recommend steps to consider if permethrin-treated cotton sta- tions are to be deployed in the Galapagos archipelago to manage P. downsi. Key words. Chewing lice, coextinction, Darwin’s finches, dilemma, ectoparasites, feather mites, Galapagos Islands, permethrin, Philornis downsi. Introduction species have closely associated species which are also endangered (Dunn et al., 2009). -
A Model of Mass Extinction
A model of mass extinction M. E. J. Newman Cornell Theory Center, Rhodes Hall, Ithaca, NY 14853. and Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501. Abstract A number of authors have in recent years proposed that the processes of macroevo- lution may give rise to self-organized critical phenomena which could have a sig- nificant effect on the dynamics of ecosystems. In particular it has been suggested that mass extinction may arise through a purely biotic mechanism as the result of so-called coevolutionary avalanches. In this paper we first explore the empirical evidence which has been put forward in favor of this conclusion. The data center principally around the existence of power-law functional forms in the distribution of the sizes of extinction events and other quantities. We then propose a new math- ematical model of mass extinction which does not rely on coevolutionary effects and in which extinction is caused entirely by the action of environmental stresses on species. In combination with a simple model of species adaptation we show that this process can account for all the observed data without the need to invoke coevo- lution and critical processes. The model also makes some independent predictions, such as the existence of “aftershock” extinctions in the aftermath of large mass extinction events, which should in theory be testable against the fossil record. arXiv:adap-org/9702003v1 12 Feb 1997 1 Introduction Building on ideas first put forward by Kauffman (1992), there has in re- cent years been increasing interest in the possibility that evolution may be a self-organized critical phenomenon (Sol´eand Bascompte 1996, Bak and Paczuski 1996). -
Climate and Deep Water Formation Regions
Cenozoic High Latitude Paleoceanography: New Perspectives from the Arctic and Subantarctic Pacific by Lindsey M. Waddell A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Oceanography: Marine Geology and Geochemistry) in The University of Michigan 2009 Doctoral Committee: Assistant Professor Ingrid L. Hendy, Chair Professor Mary Anne Carroll Professor Lynn M. Walter Associate Professor Christopher J. Poulsen Table of Contents List of Figures................................................................................................................... iii List of Tables ......................................................................................................................v List of Appendices............................................................................................................ vi Abstract............................................................................................................................ vii Chapter 1. Introduction....................................................................................................................1 2. Ventilation of the Abyssal Southern Ocean During the Late Neogene: A New Perspective from the Subantarctic Pacific ......................................................21 3. Global Overturning Circulation During the Late Neogene: New Insights from Hiatuses in the Subantarctic Pacific ...........................................55 4. Salinity of the Eocene Arctic Ocean from Oxygen Isotope -
Early to Middle Eocene History of the Arctic Ocean from Nd-Sr Isotopes in Fossil Fish Debris, Lomonosov Ridge J
PALEOCEANOGRAPHY, VOL. 24, PA2215, doi:10.1029/2008PA001685, 2009 Click Here for Full Article Early to middle Eocene history of the Arctic Ocean from Nd-Sr isotopes in fossil fish debris, Lomonosov Ridge J. D. Gleason,1 D. J. Thomas,2 T. C. Moore Jr.,1 J. D. Blum,1 R. M. Owen,1 and B. A. Haley3 Received 9 September 2008; revised 25 January 2009; accepted 8 April 2009; published 5 June 2009. [1] Strontium and neodymium radiogenic isotope ratios in early to middle Eocene fossil fish debris (ichthyoliths) from Lomonosov Ridge (Integrated Ocean Drilling Program Expedition 302) help constrain water mass compositions in the Eocene Arctic Ocean between 55 and 45 Ma. The inferred paleodepositional setting was a shallow, offshore marine to marginal marine environment with limited connections to surrounding ocean basins. The new data demonstrate that sources of Nd and Sr in fish debris were distinct from each other, consistent with a salinity-stratified water column above Lomonosov Ridge in the Eocene. The 87Sr/86Sr values of ichthyoliths (0.7079–0.7087) are more radiogenic than Eocene seawater, requiring brackish to fresh water conditions in the environment where fish metabolized Sr. The 87Sr/86Sr variations probably record changes in the overall balance of river Sr flux to the Eocene Arctic Ocean between 55 and 45 Ma and are used here to reconstruct surface water salinity values. The eNd values of ichthyoliths vary between À5.7 and À7.8, compatible with periodic (or intermittent) supply of Nd to Eocene Arctic intermediate water (AIW) from adjacent seas. Although the Norwegian-Greenland Sea and North Atlantic Ocean were the most likely sources of Eocene AIW Nd, input from the Tethys Sea (via the Turgay Strait in early Eocene time) and the North Pacific Ocean (via a proto-Bering Strait) also contributed. -
Paradigms for Parasite Conservation
Paradigms for parasite conservation Running Head: Parasite conservation Keywords: parasitology; disease ecology; food webs; economic valuation; ex situ conservation; population viability analysis 1*† 1† 2 2 Eric R. Dougherty , Colin J. Carlson , Veronica M. Bueno , Kevin R. Burgio , Carrie A. Cizauskas3, Christopher F. Clements4, Dana P. Seidel1, Nyeema C. Harris5 1Department of Environmental Science, Policy, and Management, University of California, Berkeley; 130 Mulford Hall, Berkeley, CA, 94720, USA. 2Department of Ecology and Evolutionary Biology, University of Connecticut; 75 N. Eagleville Rd, Storrs, CT, 06269, USA. 3Department of Ecology and Evolutionary Biology, Princeton University; 106A Guyton Hall, Princeton, NJ, 08544, USA. 4Institute of Evolutionary Biology and Environmental Studies, University of Zurich; Winterthurerstrasse 190 CH-8057, Zurich, Switzerland. 5Luc Hoffmann Institute, WWF International 1196, Gland, Switzerland. *email [email protected] † These authors share lead author status This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/cobi.12634. This article is protected by copyright. All rights reserved. Page 2 of 28 Abstract Parasitic species, which depend directly on host species for their survival, represent a major regulatory force in ecosystems and a significant component of Earth’s biodiversity. Yet the negative impacts of parasites observed at the host level have motivated a conservation paradigm of eradication, moving us further from attainment of taxonomically unbiased conservation goals. Despite a growing body of literature highlighting the importance of parasite-inclusive conservation, most parasite species remain understudied, underfunded, and underappreciated. -
September 2009
Coaster Brook Trout (Salvelinus fontinalis) 12-Month Finding Decision Document SEPTEMBER 2009 0 Coaster Brook Trout 12-Month Finding Decsion Document TABLE OF CONTENTS PURPOSE ............................................................................................................................................................... 1 BACKGROUND ........................................................................................................................................................... 1 DECISION STRUCTURE ........................................................................................................................................... 4 DECISION PROBLEM .................................................................................................................................................... 5 OBJECTIVES ................................................................................................................................................................. 7 ALTERNATIVES ............................................................................................................................................................. 7 CONSEQUENCES ........................................................................................................................................................ 10 TRADE-OFFS .............................................................................................................................................................. 13 DISTINCT POPULATION ANALYSIS ................................................................................................................. -
Forecasting Extinctions: Uncertainties and Limitations
Diversity 2009, 1, 133-150; doi:10.3390/d1020133 OPEN ACCESS diversity ISSN 2071-1050 www.mdpi.com/journal/diversity Review Forecasting Extinctions: Uncertainties and Limitations Richard J. Ladle 1,2 1 School of Geography and the Environment, Oxford University, South Parks Road, Oxford, UK; E-Mail: [email protected]; Tel.: +55-31-3899 1902; Fax: +55-31-3899-2735 2 Department of Agricultural and Environmental Engineering, Federal University of Viçosa, Viçosa, Brazil Received: 13 October 2009 / Accepted: 14 November 2009 / Published: 26 November 2009 Abstract: Extinction forecasting is one of the most important and challenging areas of conservation biology. Overestimates of extinction rates or the extinction risk of a particular species instigate accusations of hype and overblown conservation rhetoric. Conversely, underestimates may result in limited resources being allocated to other species/habitats perceived as being at greater risk. In this paper I review extinction models and identify the key sources of uncertainty for each. All reviewed methods which claim to estimate extinction probabilities have severe limitations, independent of if they are based on ecological theory or on rather subjective expert judgments. Keywords: extinction; uncertainty; forecasting; local extinction; viability 1. Introduction ―Prediction is very difficult, especially about the future‖ Nils Bohr, Nobel Prize winning physicist Preventing the extinction of species is probably the most emblematic objective of the global conservation movement. To fulfill this aim effectively requires that decision makers and environmental managers are provided with accurate information on: (1) the identities of specific species/populations with a high probability of going extinct without further interventions; (2) the predicted rates of extinction among a range of taxa in different geographic areas and biomes under various ecological scenarios.