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Lecture 20 - the History of Life on Earth
Lecture 20 - The History of Life on Earth Lecture 20 The History of Life on Earth Astronomy 141 – Autumn 2012 This lecture reviews the history of life on Earth. Rapid diversification of anaerobic prokaryotes during the Proterozoic Eon Emergence of Photosynthesis and the rise of O2 in the Earth’s atmosphere. Rise of Eukaryotes and the Cambrian Explosion in biodiversity at the start of the Phanerozoic Eon Colonization of land first by plants, then by animals Emergence of primates, then hominids, then humans. A brief digression on notation: “ya” = “years ago” Introduce a simple compact notation for writing the length of time before the present day. For example: “3.5 Billion years ago” “454 Million years ago” Gya = “giga-years ago”, hence 3.5 Gya = 3.5 Billion years ago Mya = “mega-years ago”, hence 454 Mya = 454 Million years ago [Note: some sources use Ga and Ma] Astronomy 141 - Winter 2012 1 Lecture 20 - The History of Life on Earth The four Eons of geological time. Hadean: 4.5 – 3.8 Gya: Formation, oceans & atmosphere Archaean: 3.8 – 2.5 Gya: Stromatolites & fossil bacteria Proterozoic: 2.5 Gya – 454 Mya: Eukarya and Oxygen Phanerozoic: since 454 Mya: Rise of plant and animal life The Archaean Eon began with the end of heavy bombardment ~3.8 Gya. Conditions stabilized. Oceans, but no O2 in the atmosphere. Stromatolites appear in the geological record ~3.5 Gya and thrived for >1 Billion years Rise of anaerobic microbes in the deep ocean & shores using Chemosynthesis. Time of rapid diversification of life driven by Natural Selection. -
Chapter 22 Notes: Introduction to Evolution
NOTES: Ch 22 – Descent With Modification – A Darwinian View of Life Our planet is home to a huge variety of organisms! (Scientists estimate of organisms alive today!) Even more amazing is evidence of organisms that once lived on earth, but are now . Several hundred million species have come and gone during 4.5 billion years life is believed to have existed on earth So…where have they gone… why have they disappeared? EVOLUTION: the process by which have descended from . Central Idea: organisms alive today have been produced by a long process of . FITNESS: refers to traits and behaviors of organisms that enable them to survive and reproduce COMMON DESCENT: species ADAPTATION: any inherited characteristic that enhances an organism’s ability to ~based on variations that are HOW DO WE KNOW THAT EVOLUTION HAS OCCURRED (and is still happening!!!)??? Lines of evidence: 1) So many species! -at least (250,000 beetles!) 2) ADAPTATIONS ● Structural adaptations - - ● Physiological adaptations -change in - to certain toxins 3) Biogeography: - - and -Examples: 13 species of finches on the 13 Galapagos Islands -57 species of Kangaroos…all in Australia 4) Age of Earth: -Rates of motion of tectonic plates - 5) FOSSILS: -Evidence of (shells, casts, bones, teeth, imprints) -Show a -We see progressive changes based on the order they were buried in sedimentary rock: *Few many fossils / species * 6) Applied Genetics: “Artificial Selection” - (cattle, dogs, cats) -insecticide-resistant insects - 7) Homologies: resulting from common ancestry Anatomical Homologies: ● comparative anatomy reveals HOMOLOGOUS STRUCTURES ( , different functions) -EX: ! Vestigial Organs: -“Leftovers” from the evolutionary past -Structures that Embryological Homologies: ● similarities evident in Molecular/Biochemical Homologies: ● DNA is the “universal” genetic code or code of life ● Proteins ( ) Darwin & the Scientists of his time Introduction to Darwin… ● On November 24, 1859, Charles Darwin published On the Origin of Species by Means of Natural Selection. -
The Evolution of a Heterogeneous Martian Mantle: Clues from K, P, Ti, Cr, and Ni Variations in Gusev Basalts and Shergottite Meteorites
Earth and Planetary Science Letters 296 (2010) 67–77 Contents lists available at ScienceDirect Earth and Planetary Science Letters journal homepage: www.elsevier.com/locate/epsl The evolution of a heterogeneous Martian mantle: Clues from K, P, Ti, Cr, and Ni variations in Gusev basalts and shergottite meteorites Mariek E. Schmidt a,⁎, Timothy J. McCoy b a Dept. of Earth Sciences, Brock University, St. Catharines, ON, Canada L2S 3A1 b Dept. of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560-0119, USA article info abstract Article history: Martian basalts represent samples of the interior of the planet, and their composition reflects their source at Received 10 December 2009 the time of extraction as well as later igneous processes that affected them. To better understand the Received in revised form 16 April 2010 composition and evolution of Mars, we compare whole rock compositions of basaltic shergottitic meteorites Accepted 21 April 2010 and basaltic lavas examined by the Spirit Mars Exploration Rover in Gusev Crater. Concentrations range from Available online 2 June 2010 K-poor (as low as 0.02 wt.% K2O) in the shergottites to K-rich (up to 1.2 wt.% K2O) in basalts from the Editor: R.W. Carlson Columbia Hills (CH) of Gusev Crater; the Adirondack basalts from the Gusev Plains have more intermediate concentrations of K2O (0.16 wt.% to below detection limit). The compositional dataset for the Gusev basalts is Keywords: more limited than for the shergottites, but it includes the minor elements K, P, Ti, Cr, and Ni, whose behavior Mars igneous processes during mantle melting varies from very incompatible (prefers melt) to very compatible (remains in the shergottites residuum). -
Callisto: a Guide to the Origin of the Jupiter System
A PAPER SUBMITTED TO THE DECADAL SURVEY ON PLANETARY SCIENCE AND ASTROBIOLOGY Callisto: A Guide to the Origin of the Jupiter System David E Smith 617-803-3377 Department of Earth, Atmospheric and PLanetary Sciences Massachusetts Institute of Technology, Cambridge MA 02139 [email protected] Co-authors: Francis Nimmo, UCSC, [email protected] Krishan Khurana, UCLA, [email protected] Catherine L. Johnson, PSI, [email protected] Mark Wieczorek, OCA, Fr, [email protected] Maria T. Zuber, MIT, [email protected] Carol Paty, University of Oregon, [email protected] Antonio Genova, Univ Rome, It, [email protected] Erwan Mazarico, NASA GSFC, [email protected] Louise Prockter, LPI, [email protected] Gregory A. Neumann, NASA GSFC Emeritus, [email protected] John E. Connerney, Adnet Systems Inc., [email protected] Edward B. Bierhaus, LMCO, [email protected] Sander J. Goossens, UMBC, [email protected] MichaeL K. Barker, NASA GSFC, [email protected] Peter B. James, Baylor, [email protected] James Head, Brown, [email protected] Jason Soderblom, MIT, [email protected] July 14, 2020 Introduction Among the GaLiLean moons of Jupiter, it is outermost CaLListo that appears to most fulLy preserve the record of its ancient past. With a surface aLmost devoid of signs of internaL geologic activity, and hints from spacecraft data that its interior has an ocean whiLe being only partiaLLy differentiated, CaLListo is the most paradoxicaL of the giant rock-ice worlds. How can a body with such a primordiaL surface harbor an ocean? If the interior was warm enough to form an ocean, how could a mixed rock and ice interior remain stable? What do the striking differences between geologicaLLy unmodified CaLListo and its sibling moon Ganymede teLL us about the formation of the GaLiLean moons and the primordiaL conditions at the time of the formation of CaLListo and the accretion of giant planet systems? The answers can be provided by a CaLListo orbitaL mission. -
Timeline of the Evolutionary History of Life
Timeline of the evolutionary history of life This timeline of the evolutionary history of life represents the current scientific theory Life timeline Ice Ages outlining the major events during the 0 — Primates Quater nary Flowers ←Earliest apes development of life on planet Earth. In P Birds h Mammals – Plants Dinosaurs biology, evolution is any change across Karo o a n ← Andean Tetrapoda successive generations in the heritable -50 0 — e Arthropods Molluscs r ←Cambrian explosion characteristics of biological populations. o ← Cryoge nian Ediacara biota – z ← Evolutionary processes give rise to diversity o Earliest animals ←Earliest plants at every level of biological organization, i Multicellular -1000 — c from kingdoms to species, and individual life ←Sexual reproduction organisms and molecules, such as DNA and – P proteins. The similarities between all present r -1500 — o day organisms indicate the presence of a t – e common ancestor from which all known r Eukaryotes o species, living and extinct, have diverged -2000 — z o through the process of evolution. More than i Huron ian – c 99 percent of all species, amounting to over ←Oxygen crisis [1] five billion species, that ever lived on -2500 — ←Atmospheric oxygen Earth are estimated to be extinct.[2][3] Estimates on the number of Earth's current – Photosynthesis Pong ola species range from 10 million to 14 -3000 — A million,[4] of which about 1.2 million have r c been documented and over 86 percent have – h [5] e not yet been described. However, a May a -3500 — n ←Earliest oxygen 2016 -
Plant Evolution an Introduction to the History of Life
Plant Evolution An Introduction to the History of Life KARL J. NIKLAS The University of Chicago Press Chicago and London CONTENTS Preface vii Introduction 1 1 Origins and Early Events 29 2 The Invasion of Land and Air 93 3 Population Genetics, Adaptation, and Evolution 153 4 Development and Evolution 217 5 Speciation and Microevolution 271 6 Macroevolution 325 7 The Evolution of Multicellularity 377 8 Biophysics and Evolution 431 9 Ecology and Evolution 483 Glossary 537 Index 547 v Introduction The unpredictable and the predetermined unfold together to make everything the way it is. It’s how nature creates itself, on every scale, the snowflake and the snowstorm. — TOM STOPPARD, Arcadia, Act 1, Scene 4 (1993) Much has been written about evolution from the perspective of the history and biology of animals, but significantly less has been writ- ten about the evolutionary biology of plants. Zoocentricism in the biological literature is understandable to some extent because we are after all animals and not plants and because our self- interest is not entirely egotistical, since no biologist can deny the fact that animals have played significant and important roles as the actors on the stage of evolution come and go. The nearly romantic fascination with di- nosaurs and what caused their extinction is understandable, even though we should be equally fascinated with the monarchs of the Carboniferous, the tree lycopods and calamites, and with what caused their extinction (fig. 0.1). Yet, it must be understood that plants are as fascinating as animals, and that they are just as important to the study of biology in general and to understanding evolutionary theory in particular. -
Dwarf Planet Ceres
Dwarf Planet Ceres drishtiias.com/printpdf/dwarf-planet-ceres Why in News As per the data collected by NASA’s Dawn spacecraft, dwarf planet Ceres reportedly has salty water underground. Dawn (2007-18) was a mission to the two most massive bodies in the main asteroid belt - Vesta and Ceres. Key Points 1/3 Latest Findings: The scientists have given Ceres the status of an “ocean world” as it has a big reservoir of salty water underneath its frigid surface. This has led to an increased interest of scientists that the dwarf planet was maybe habitable or has the potential to be. Ocean Worlds is a term for ‘Water in the Solar System and Beyond’. The salty water originated in a brine reservoir spread hundreds of miles and about 40 km beneath the surface of the Ceres. Further, there is an evidence that Ceres remains geologically active with cryovolcanism - volcanoes oozing icy material. Instead of molten rock, cryovolcanoes or salty-mud volcanoes release frigid, salty water sometimes mixed with mud. Subsurface Oceans on other Celestial Bodies: Jupiter’s moon Europa, Saturn’s moon Enceladus, Neptune’s moon Triton, and the dwarf planet Pluto. This provides scientists a means to understand the history of the solar system. Ceres: It is the largest object in the asteroid belt between Mars and Jupiter. It was the first member of the asteroid belt to be discovered when Giuseppe Piazzi spotted it in 1801. It is the only dwarf planet located in the inner solar system (includes planets Mercury, Venus, Earth and Mars). Scientists classified it as a dwarf planet in 2006. -
Thermal and Crustal Evolution of Mars Steven A
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. E7, 10.1029/2001JE001801, 2002 Thermal and crustal evolution of Mars Steven A. Hauck II1 and Roger J. Phillips McDonnell Center for the Space Sciences and Department of Earth and Planetary Sciences, Washington University, Saint Louis, Missouri, USA Received 11 October 2001; revised 4 February 2002; accepted 11 February 2002; published 16 July 2002. [1] We present a coupled thermal-magmatic model for the evolution of Mars’ mantle and crust that may be consistent with estimates of the average crustal thickness and crustal growth rate. By coupling a simple parameterized model of mantle convection to a batch- melting model for peridotite, we can investigate potential conditions and evolutionary paths of the crust and mantle in a coupled thermal-magmatic system. On the basis of recent geophysical and geochemical studies, we constrain our models to have average crustal thicknesses between 50 and 100 km that were mostly formed by 4 Ga. Our nominal model is an attempt to satisfy these constraints with a relatively simple set of conditions. Key elements of this model are the inclusion of the energetics of melting, a wet (weak) mantle rheology, self-consistent fractionation of heat-producing elements to the crust, and a near- chondritic abundance of those elements. The latent heat of melting mantle material is a small (percent level) contributor to the total planetary energy budget over 4.5 Gyr but is crucial for constraining the thermal and magmatic history of Mars. Our nominal model predicts an average crustal thickness of 62 km that was 73% emplaced by 4 Ga. -
THE PENNY MOON and QUARTER EARTH School Adapted from a Physics Forum Activity At
~ LPI EDUCATION/PUBLIC OUTREACH SCIENCE ACTIVITIES ~ Ages: 5th grade – high THE PENNY MOON AND QUARTER EARTH school Adapted from a Physics Forum activity at: http://www.phvsicsforums.com/ Duration: 10 minutes OVERVIEW — The students will use a penny and a quarter to model the Moon’s rotation on its axis and Materials: revolution around the Earth, and demonstrate that the Moon keeps the same face toward One penny and one the Earth. quarter per pair of students OBJECTIVE — Overhead projector, or The students will: elmo, or video Demonstrate the motion of the Moon’s rotation and revolution. projector Compare what we would see of the Moon if it did not rotate to what we see when its period of rotation is the same as its orbital period. Projected image of student overhead BEFORE YOU START: Do not introduce this topic along with the reason for lunar phases; students may become confused and assume that the Moon’s rotation is related to its phases. Prepare to show the student overhead projected for the class to see. ACTIVITY — 1. Ask your students to describe which parts of the Moon they see. Does the Moon turn? Can we see its far side? Allow time for your students to discuss this and share their opinions. 2. Hand out the pennies and quarters so that each pair of students has both. Tell the students that they will be creating a model of the Earth and Moon. Which object is Earth? [the quarter] Which one is the Moon? [the penny] 3. Turn on the projected student overhead. -
38—GEOLOGIC AGE SYMBOL FONT (Stratagemage) REF NO STRATIGRAPHIC AGE SUBDIVISION TYPE AGE SYMBOL KEYBOARD POSITION for Stratagemage FONT
Federal Geographic Data Committee U.S. Geological Survey Open-File Report 99–430 Public Review Draft - Digital Cartographic Standard for Geologic Map Symbolization PostScript Implementation (filename: of99-430_38-01.eps) 38—GEOLOGIC AGE SYMBOL FONT (StratagemAge) REF NO STRATIGRAPHIC AGE SUBDIVISION TYPE AGE SYMBOL KEYBOARD POSITION FOR StratagemAge FONT 38.1 Archean Eon A Not applicable (use Helvetica instead) 38.2 Cambrian Period _ (underscore = shift-hyphen) 38.3 Carboniferous Period C Not applicable (use Helvetica instead) 38.4 Cenozoic Era { (left curly bracket = shift-left square bracket) 38.5 Cretaceous Period K Not applicable (use Helvetica instead) 38.6 Devonian Period D Not applicable (use Helvetica instead) 38.7 Early Archean (3,800(?)–3,400 Ma) Era U Not applicable (use Helvetica instead) 38.8 Early Early Proterozoic (2,500–2,100 Ma) Era R (capital R = shift-r) 38.9 Early Middle Proterozoic (1,600–1,400 Ma) Era G (capital G = shift-g) 38.10 Early Proterozoic Era X Not applicable (use Helvetica instead) 38.11 Eocene Epoch # (pound sign = shift-3) 38.12 Holocene Epoch H Not applicable (use Helvetica instead) 38.13 Jurassic Period J Not applicable (use Helvetica instead) 38.14 Late Archean (3,000–2,500 Ma) Era W Not applicable (use Helvetica instead) 38.15 Late Early Proterozoic (1,800–1,600 Ma) Era I (capital I = shift-i) 38.16 Late Middle Proterozoic (1,200–900 Ma) Era E (capital E = shift-e) 38.17 Late Proterozoic Era Z Not applicable (use Helvetica instead) 38.18 Mesozoic Era } (right curly bracket = shift-right square bracket) 38.19 Middle Archean (3,400–3,000 Ma) Era V Not applicable (use Helvetica instead) 38.20 Middle Early Proterozoic (2,100–1,800 Ma) Era L (capital L = shift-l) 38.21 Middle Middle Proterozoic (1,400–1,200 Ma) Era F (capital F = shift-f) 38.22 Middle Proterozoic Era Y Not applicable (use Helvetica instead) A–38–1 Federal Geographic Data Committee U.S. -
Convective Isolation of Hadean Mantle Reservoirs Through Archean Time
Convective isolation of Hadean mantle reservoirs through Archean time Jonas Tuscha,1, Carsten Münkera, Eric Hasenstaba, Mike Jansena, Chris S. Mariena, Florian Kurzweila, Martin J. Van Kranendonkb,c, Hugh Smithiesd, Wolfgang Maiere, and Dieter Garbe-Schönbergf aInstitut für Geologie und Mineralogie, Universität zu Köln, 50674 Köln, Germany; bSchool of Biological, Earth and Environmental Sciences, The University of New South Wales, Kensington, NSW 2052, Australia; cAustralian Center for Astrobiology, The University of New South Wales, Kensington, NSW 2052, Australia; dDepartment of Mines, Industry Regulations and Safety, Geological Survey of Western Australia, East Perth, WA 6004, Australia; eSchool of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, United Kingdom; and fInstitut für Geowissenschaften, Universität zu Kiel, 24118 Kiel, Germany Edited by Richard W. Carlson, Carnegie Institution for Science, Washington, DC, and approved November 18, 2020 (received for review June 19, 2020) Although Earth has a convecting mantle, ancient mantle reservoirs anomalies in Eoarchean rocks was interpreted as evidence that that formed within the first 100 Ma of Earth’s history (Hadean these rocks lacked a late veneer component (5). Conversely, the Eon) appear to have been preserved through geologic time. Evi- presence of some late accreted material is required to explain the dence for this is based on small anomalies of isotopes such as elevated abundances of highly siderophile elements (HSEs) in 182W, 142Nd, and 129Xe that are decay products of short-lived nu- Earth’s modern silicate mantle (9). Notably, some Archean rocks clide systems. Studies of such short-lived isotopes have typically with apparent pre-late veneer like 182W isotope excesses were focused on geological units with a limited age range and therefore shown to display HSE concentrations that are indistinguishable only provide snapshots of regional mantle heterogeneities. -
Geologic Time Lesson Guide Lesson Guide | Description
Geologic Time Lesson Guide Lesson Guide | Description Instructor: Dr. Michael T. Lewchuk Grade Level: 6 - 12 Subject: Earth & Physical Science Students will investigate the subdivisions of the Geologic Time Scale. Wonder How: Have you ever wondered how scientists and geologists know how old something is? Goal: Students will gather data and use ratios that will help them create a scale model of Geological time using simple materials found at home. Lesson Guide | Lesson Guide Agenda Lesson Guide Agenda: v Vocabulary v Materials List v Geologic Time Scale v Activity Instructions v Challenge! v Additional Resources v Oklahoma Academic Standards Lesson Guide | Vocabulary Eon – An Eon is the fundamental division of time in Geology. The Earth’s 4.6-billion- year history is divided into four Eons: Hadean, Archean, Proterozoic and Phanerozoic. Precambrian Supereon – This is the combination of the Hadean, Archean and Proterozoic Eons. It is subdivided based on the physical properties of the Earth’s surface and atmosphere. Hadean Eon – The Hadean is the oldest Eon. It is generally described as the time when the Earth was so hot that it was all, or mostly all, molten liquid. Archean Eon – The Archean Eon is generally described as the time when solid rock existed on the surface of the Earth, but little or no free oxygen existed in the atmosphere. Proterozoic Eon – The Proterozoic is generally considered the Eon when free oxygen began to appear in the atmosphere. Microscopic life developed during the Proterozoic. Lesson Guide | Vocabulary Phanerozoic Eon – The Phanerozoic Eon is the most recent Eon in geologic history.