Life in the UniverseLife in the Universe Evidence for Cometary Panspermia

Prof. Richard B. Hoover Astrobiology Group Leader Visiting Research Professor

Athens State University Buckingham University

Athens, AL USA Buckingham, UK

ISINN-25

25th International Seminar on Interaction of Neutrons with Nuclei

Dubna, Russia May 23, 2017

Life in the Universe Life in the Universe

INTRODUCTION Where, How & When Life Originated is Great Unanswered Question

~560 B.C.: Anaximander Proposes Spontaneous Generation Hypothesis

~450 B.C.: Anaxagoras Proposes Panspermia Hypothesis (Seeds Everywhere).

1861: Pasteur disproves Spontaneous Generation--Life from Non-Living Matter

1871: Panspermia Advanced By Lord Kelvin; Arrhenius (1903); Hoyle (1986)

1871: Darwin argues Origin of Life by Natural Processes in “Warm Little Pond”

1924: A. I. Oparin Developed Chemical Evolution Model and Suggests Asteroids

and Interstellar Dust Particles Deliver Water and Organics to the Biosphere

1953: Miller-Urey -Amino Acids Could Form in Primordial Earth Atmosphere

1953: Watson-Crick-Franklin Discover Structure of DNA Molecule

Origin of Life Believed Solved –Pre-Biotic Chemistry in Earth’s Early Atmosphere &

Oceans Slowly Produced Amino Acids, Biomolecules, Coacervates & Membranes

That Evolve Into Protocells, Simple Cells, Protozoa & Complex Multicellular Life

Life in the Universe Life in the Universe

Endogenous Origin of Life Current Hypothesis (Paradigm)

In 1953, it was known Earth formed ~ 4.5Billion Years Ago;

Fossils Known at that Time Suggested Cyanobacteria &

Cells Appeared ~2.5 Billion Years Ago. This Allows ~2

Billion Years for Long Slow Chemical Evolution Process

before First Simple Living Cells Appeared on Earth

Earth Considered a Closed System. All Earth Life Originates

on Earth. Pre-Biotic Synthesis of Amino Acids and other

Biomolecules in Earth’s Primitive Reducing Atmosphere

and Oceans Leads to RNA World, Proteins, Membranes &

Protocells Evolving into Complex Multicellular Organisms

Life in the Universe Life in the Universe

Sharov, A. and Gordon, R. Life Before Earth, arXiv.1304.3381, 2013

Genomic Extrapolation Suggests Life Originated 9.7 Billion Years Ago --- ~ 5.2

Billion Years Before Formation of Our Solar System and Planet Earth

Timeline by Linear Regression Genetic Complexity

Endogenous Origin of Life: Problems Biomolecules & Microfossils Indicate Life Appeared on Earth When

Hadean Earth Had Cooled Enough to Allow Liquid Water Oceans

Time Period for Long, Slow Process of Pre-Biotic Chemical Evolution

Before Formation of First Living Cells Not Available on Earth

Life in the Universe Life in the Universe

Endogenous Origin of Life: Problems All 20 Protein Amino Acids not Formed by Miller-Urey

Abiotic Homochirality Never Obtained in Laboratory

Phosphate (PO43-) was virtually absent on Early Earth

Goldford et al. Remnants of an Ancient Metabolism Without Phosphate, Cell, 2017

Phosphate/Phosphorylation is Essential to Genetic

(RNA/DNA) & Metabolic Machinery (ATP) of Life

RNA World Hypothesis vs. Iron-Sulfur World Hypothesis

If Ancient Biochemistry of Life on Earth Originated with

Iron & Sulfur ---- Where, How, and When Did Genetic

and Metabolic Machinery Change So That Phosphate

Became Absolutely Essential For All Life on Earth?

Life in the Universe Life in the Universe

Endogenous Origin of Life: Problems Origin of Membranes, RNA/DNA, Proteins, Enzymes& Cells

Genetics First – RNA World Metabolism First - Protein World

Discoveries in Past 50 years in Paleontology, Microbiology,

Biochemistry Molecular Biology & Genomics Reveal:

Simple Cells Do Not Exist Proteins, Enzymes, Bacteria&Protozoa are Complex

Life on Earth: 4.2-3.8 Gya

Gya

Mozzis S.J. et al. “Evidence for Life on Earth before 3,800

Million Years Ago.” Nature 384, 55-59 (1996).

Dodd, M. S. et al., Evidence for early life in Earth's oldest

hydrothermal vent precipitates. Nature, 543, 60-64 (2017)

Human Genome 3.2 Gbp

Polychaos dubium 670 Gbp

Biogenic Carbon Isotopes in Isua Apatite Grains;

Filamentous Fossils in 4.2-3.8 Gya Ferruginous

Sedimentary Hydrothermal Vent Rocks,

Nuvvuagittuq Belt, Quebec, Canada

DNA Gyrase TEM of Bacterial

Enzyme Flagellar Motor

Life in the UniverseLife in the Universe Exogenous Origin of Life

Alternate Hypothesis (Panspermia) Earth Life Originated Elsewhere and was Delivered to Early

Earth as Spores or Intact Cells Soon After Oceans Appear 1871 Von Helmholtz: 1871 Von Helmholtz: “who could say whether the comets and meteors “who could say whether the comets and meteors

which swarm everywhere through space, may not scatter germs which swarm everywhere through space, may not scatter germs

wherever a new world has reached the stage in which it is a suitable wherever a new world has reached the stage in which it is a suitable

place for organic beings.” place for organic beings.” -- Cometary PanspermiaCometary Panspermia

1903 1903 SvanteSvante Arrhenius: Spores of living Organisms Escape Planetary Arrhenius: Spores of living Organisms Escape Planetary

Atmospheres and Propelled Atmospheres and Propelled throuhoutthrouhout Cosmos by Radiation Cosmos by Radiation

PressurePressure--RadiopanspermiaRadiopanspermia ––Radiation Survival ProblemRadiation Survival Problem

1973 1973 OrgelOrgel & Crick:& Crick: Intelligent Seeding Intelligent Seeding -- Directed PanspermiaDirected Panspermia

1981 Hoyle & Wickramasinghe: 1981 Hoyle & Wickramasinghe: Cometary PanspermiaCometary Panspermia

Life in the UniverseLife in the Universe Exogenous Origin of Life

Cometary Panspermia Hypothesis

Dramatically Alters the Time Period Available for Pre-Biotic

Biochemistry, Molecular and Cellular Evolution.

Comets and Meteorites Provide a Wide Array of Conditions

Available for either the RNA World or the Iron-Sulfur

World Scenarios to Lead to the Origin of Life

Cometary Jets Allow Concentration of Solutes. Spinning

Comet Near Star Gives Natural DNA/PCR Conditions

Provides Mechanism for Distribution of Life Once Formed Provides Mechanism for Distribution of Life Once Formed

Cometary PanspermiaCometary Panspermia

Wickramasinghe & Hoyle, “Infrared Radiation from Wickramasinghe & Hoyle, “Infrared Radiation from Comet HaleComet Hale--Bopp.” Bopp.” AstrophysAstrophys.& Spa. Sci. .& Spa. Sci. 268, 1999268, 1999

IR Spectrum of GC-IRS7 and Diatom Model

Comet Hale-Bopp 4/5/97- 5 Days after

Perihelion. Photo: Univ. of Hawaii

1986- Hoover, Hoyle et al. Propose that Diatoms

Could Live and Grow on Comets and Europa.

Diatom Silica Can Explain Interstellar Dust IR

Spectra of Trapezium Nebula and GC-IRS 7

Life in the Universe Life in the Universe

Cometary Panspermia Problems Does Not Answer Fundamental Question of Origin of Life

Suggest Life on Earth Did Not Originate on Earth

If Earth Life Originated Elsewhere in Our Solar System

(Mars, Europa, Enceladus) or Nearby Star System Could

it Have Been Delivered to Early Earth Along with Water

and Organics by Comets, Asteroids and Meteorites?

Could Living Cells/Spores Inhabit Comets?

Could Viable Cells Survive Long Exposure to Space

Environment (Vacuum, Thermal Extremes, Solar Wind,

UV, g Rays, High Energy Galactic Cosmic Rays and

Heating/Shock of Entry into Earth’s Atmosphere?

Life in the Universe Life in the Universe

ExtraSolar Comets

Oldest Known Star - HD 140283 ~ 14.5 +/- 0.8 Billion Years

186 light-yrs from Earth and Affords ~ 10 Billion Years

more than Earth for Long, Slow Chemical Evolution

Process. Escape Velocity of Interstellar Comet (20 km/sec)

Transit from HD 140283 to Earth ~ 2.7 Million yrs

Recent Discoveries in Siberian Permafrost and Beacon

Valley Antarctic Ice Prove Microorganisms (as Viable

Spores & Cells) Can Survive Frozen in Ice for more than

8.3 Million Years. Kilometer Thick Layers of Ice Crust,

Rocks Could Shield Microbes from Solar Wind, Gamma

Rays and Highest Energy Galactic Cosmic Ray Nuclei,

Life in Ancient Ice Life in Ancient Ice

Living bacteria and diatoms Living bacteria and diatoms

found in 3.7 km thick ice found in 3.7 km thick ice

sheet and in sheet and in subglacialsubglacial Lake Lake

VostokVostok beneath beneath VostokVostok

Station in AntarcticaStation in Antarctica

Diatoms from 2827 M coreDiatoms from 2827 M core

Life in Ancient Ice Life in Ancient Ice

2010 Hoover & Pikuta Isolate Cyanobacteria & Living 2010 Hoover & Pikuta Isolate Cyanobacteria & Living

Bacteria from stomach of Bacteria from stomach of LyubaLyuba 40,000 year old 40,000 year old

Mammoth from Siberian PermafrostMammoth from Siberian Permafrost

C 84%

O 11%

N 2%

X

Life in Ice: Life in Ice: Microbial Microbial Extremophiles Extremophiles from from 2008 2008

SchirmacherSchirmacher Oasis Oasis Expedition Expedition ---- Comet AnalogComet Analog

Ice Cave

Sanguibacter gelidistatuariae sp. nov., a novel psychrotolerant anaerobe from an ice sculpture in Antarctica, and emendation of descriptions for the

family Sanguibacteraceae, the genus Sanguibacter and species S. antarcticus, S. inulinus, S. kedieii, S. marinus, S.soli and S. suarezii .

Elena V. Pikuta, Richard B. Hoover, et al., Int. Jour. Systematic & Evolutionary Biology, 2017 (IN PRESS)

Mini-Planets form in Ice Sculpture as

Sunlight Heats Black Rocks making

Meltwater Pools. Photosynthetic

Bacteria Grow and Release O2

Forming Mini-Atmosphere in Ice

New Species of Bacteria

from Ice Sculpture

Europa Oceans & Possible LifeEuropa Oceans & Possible Life

Red, Purple & Golden Brown Colors ~ Pigments in Polar Microbes

Thrace

Region

Conamara Chaos Region (70X30 km)

Herminiimonas glaciei

Loveland –Curtze et. al.

3042 M in Greenland Ice Core

Minos Linea Region

Geysers & Liquid Water Seas Geysers & Liquid Water Seas

on Saturn’s Moon Enceladuson Saturn’s Moon Enceladus

Cassini Mission Detects Water Ice Geysers

from Tiger Stripes near South Pole of

Enceladus

Temp. at Tiger Stripes ~ 273 KTemp. at Tiger Stripes ~ 273 K

Cassini Gravity Data indicates vast Regional

Subsurface Sea of Liquid Water Sea at

Depth of 30 to 40 km up to 50o S Latitude

Less at al. “The Gravity Field and Interior

Structure of Enceladus” Science 344, 78-80,

(2014)

O2 in Enceladus & Rhea from ice

decomposition by magnetospheric plasma

DAWN DISCOVERS DAWN DISCOVERS

WaterWater--Ice/Organics on Pluto & Ice/Organics on Pluto & CharonCharon

New Mountains, Polygons & Ice Flows on Pluto indicate Oceans

Red&Orange colors from Tholins or Pigments. Sub-Ice Oceans and

Cryovolcanism on Charon Credit: NASA/GSFC;JHUAPL;SwRI

Comets, Meteorites and the Origin Comets, Meteorites and the Origin

and Evolution of the Biosphereand Evolution of the Biosphere Comets acrete IDP’s, Planetary & Cosmic Debris

Comets are not “Pristine” ProtoSolar Nebular Material

Stardust Stardust NExTNExT Image Image

of Comet 9P/Temple 1of Comet 9P/Temple 1 • Comets are Probable Parent

Bodies of CI1 & CM2 Meteorites

• Carbonaceous Meteorites: Ice,

Water & Low Temperature

Aqueous Alteration of Minerals

•Dominant Minerals: Pyrite,

Griegite, Montmorillionite Clay,

and Magnesium Sulfate

•Tumbling & Orbits give

alternate Freeze Thaw Cycles

and Exposure to Vacuum.

Comets, Meteorites and the Origin Comets, Meteorites and the Origin

and Evolution of the Biosphereand Evolution of the Biosphere DeuteriumDeuterium--Hydrogen Ratio Hydrogen Ratio

D/H (x 10D/H (x 10--66))

Comets: 290Comets: 290--330330

CI1 Meteorite: 185CI1 Meteorite: 185--545545

Earth’s Oceans: 149 Earth’s Oceans: 149 ±± 33

Proto Solar Nebula: 21Proto Solar Nebula: 21

Jupiter/Saturn: 15Jupiter/Saturn: 15--3535

Interstellar Medium: 16Interstellar Medium: 16

Similarity of D/H of Comets toSimilarity of D/H of Comets to

CI1 meteorites & Earth’s OceansCI1 meteorites & Earth’s Oceans

Robert et al. (2000) “The Solar System D/H ratio: Observations and Theories.” Space Sci. Rev., 92, 201-224.

Comets, Meteorites and the Origin Comets, Meteorites and the Origin

and and EvolutionEvolution of the Biosphereof the Biosphere

Hypothesis: Comets are “Dirty Snowballs” and Hypothesis: Comets are “Dirty Snowballs” and PereniallyPerenially

Frozen Frozen -- Liquid Water Cannot Exist on Comets Liquid Water Cannot Exist on Comets -- InvalidInvalid

Deep-Impact Data Reveals Evidence for Liquid Water, Jets

& High Temperature of Nucleus of Comet 9P/Temple 1

Biomolecules and Microfossils in Biomolecules and Microfossils in

Orgueil CI1 Carbonaceous MeteoriteOrgueil CI1 Carbonaceous Meteorite

May 14, 1864, 8:00 A. M. – CI1 Carbonaceous Meteorite Falls in

Orgueil, France – Over 20 Stones Recovered

Parent Body of Orgueil Meteorite is Halley-Type or Jupiter Family of Comets

Orgueil Meteorite Contains Abundant Microfossils

Biomolecules in Carbonaceous Meteorites Biomolecules in Carbonaceous Meteorites

Twenty amino acids are in all Proteins of all Life on Earth

Only Eight are Found in Orgueil & Murchison meteorites. Twelve are Missing (Rules out recent bio-contaminants)

GLY

2919 ppb

ALA

720/956 ppb

GLU

537/801 ppb

ASP 100/342 ppb

PRO

LEU

VAL

ILEU

Extraterrestrial Extraterrestrial NucleobasesNucleobases in Murchison in Murchison

CM2 Carbonaceous Meteorites CM2 Carbonaceous Meteorites

Martins Martins et al., Extraterrestrial et al., Extraterrestrial NucleobasesNucleobases in the Murchison Meteorite. Earth & in the Murchison Meteorite. Earth & Planetary Letters, Planetary Letters, 279,279, 130130--136, (2008).136, (2008).

CytosineCytosineUracilUracil: Half: Half--Life 17,000 YearsLife 17,000 Years

ThymineThymineXanthineXanthine: Half: Half--Life 1.3 Ma @ 0 C; pH 7Life 1.3 Ma @ 0 C; pH 7 Levy, M. & Miller, S. L. Levy, M. & Miller, S. L. The Stability of RNA Bases: Implications to the Origin of Life, PNAS, The Stability of RNA Bases: Implications to the Origin of Life, PNAS,

95,95, 79337933--7938, (1998).7938, (1998).

Unstable Unstable NucleobasesNucleobases Thymine & Cytosine AbsentThymine & Cytosine Absent BIOBIO--CONTAMINATED METEORITES SHOULD CONTAIN CONTAMINATED METEORITES SHOULD CONTAIN

URACIL; GUANINE; ADENINE; URACIL; GUANINE; ADENINE; CYTOSINE; & THYMINECYTOSINE; & THYMINE

Evidence of Cells, Trichomes, and Sheath in

Orgueil CI1 Carbonaceous Meteorite

BSED image of 10 µm diameter filament with thick electron transparent sheath BSED image of 10 µm diameter filament with thick electron transparent sheath enclosing single linear chain (trichome) of 1.8 µm dia. X 5.5 µm long cellsenclosing single linear chain (trichome) of 1.8 µm dia. X 5.5 µm long cells

Embedded Prokaryotic Filaments

in the Orgueil CI1 Meteorite

Embedded Prokaryotic Filaments

in the Orgueil CI1 Meteorite: EDS X-Ray Maps

BSED & SED Images & Elemental XBSED & SED Images & Elemental X--Ray Maps of Filaments Ray Maps of Filaments

Nitrogen in Pleistocene Mammoth Nitrogen in Pleistocene Mammoth

Guard HairGuard Hair

Distinct EDS Nitrogen Peak in 32,000 Yr Old

Mammoth Hair N = 11.6% Atomic

C: 73.4%

O: 13.6%

N: 11.6%

P: 0.00%

S: 1.16%

Mg: .02%

Missing Nitrogen in Meteorite

Microfossils and Trilobites

Nitrogen Absent in Carbon-rich Cyanobacteria

Filament Embedded in Orgueil CI1 Meteorite

Kerogenous Cyanobacterial Filament with Apical Cell Kerogenous Cyanobacterial Filament with Apical Cell

C 43.8%; O 14.8%; V 2.6% C 43.8%; O 14.8%; V 2.6% (O/C = 0.34; N < 0.5%)(O/C = 0.34; N < 0.5%)

Fossil Acritarch in Orgueil CI1 Metrorite

Morphotype of Acritarch Morphotype of Acritarch Leiospheridia sp.

Tapered Filaments in Orgueil with Heterocysts

Living Living Calothrix sp. Calothrix sp. with Heterocyst. Tapered filaments in with Heterocyst. Tapered filaments in Orgueil with Basal HeterocystsOrgueil with Basal Heterocysts

FIMBRIAE OF CYANOBACTERIA IN ORGUEIL CI1

CARBONACEOUS METEORITE

Lophotrichous Tufts Of Fimbriae on Polarized Orgueil FilamentsLophotrichous Tufts Of Fimbriae on Polarized Orgueil Filaments

EDS Data of Sheath and Filament in Orgueil

Epsomite infilled Cyanobacterial Filament (O/C=0.2) with Emergent Epsomite infilled Cyanobacterial Filament (O/C=0.2) with Emergent Trichomes and Kerogenous Sheath (N< 0.3%; O/C=0.1) Trichomes and Kerogenous Sheath (N< 0.3%; O/C=0.1)

Polar Plankton Diatoms in Polonnaruwa Meteorite

Meteorite Fossil Filament Meteorite Fossil Filament

Compared with Earth Polar Compared with Earth Polar

Marine Marine Aulacoseira ambiguaAulacoseira ambigua

Extinct Hystrichosphere or Prasinophyte in

Polonnaruwa Meteorite

C

Al

RECENT DISCOVERIESRECENT DISCOVERIES Diatoms & Desmids on ISS WindowDiatoms & Desmids on ISS Window

Planktonic Cymbella sp. & Desmids on Outside of ISS

RECENT DISCOVERIESRECENT DISCOVERIES Algae & Cyanobacteria Survive 450 Algae & Cyanobacteria Survive 450

Days Outside ISS in BIOMEX LabDays Outside ISS in BIOMEX Lab

Nostoc sp. & Sphaerocystis sp. Outside ISS - 2/13/17

Diatoms Discovered in Orgueil on 19/5/17 at Astrobiology Diatoms Discovered in Orgueil on 19/5/17 at Astrobiology

Sector, Laboratory of Radiation Biology, JINR Sector, Laboratory of Radiation Biology, JINR

Tescan Vega3 SEM - May19, 2017

Cyanobacterial Sheath, Cyanobacterial Sheath, FramboidFramboid, Plates, Spines & , Plates, Spines & AlveolataAlveolata in in

OrgueilOrgueil--Astrobiology Sector, Laboratory of Radiation Biology, JINR Astrobiology Sector, Laboratory of Radiation Biology, JINR

Cyanobacterial Sheath and

Framboid in Orgueil CI1

Carbonaceous Meteorite

Framboid with Plates and

Spines of Alveolata in Orgueil

Alveolata in Orgueil

Diatoms Discovered in Orgueil on 19/5/17 at Astrobiology Diatoms Discovered in Orgueil on 19/5/17 at Astrobiology

Sector, Laboratory of Radiation Biology, JINR Sector, Laboratory of Radiation Biology, JINR

Pinnularia sp. Beacon Valley, Antarctica

8.3 Mya Miocene Glacier (16.2mX3.4 m )

Pinnularia sp.

Orgueil Meteorite

(17.1m X 3.2 m )

Pinnularia segariana, New Zealand

17.1m X 3.8 m

Life in the UniverseLife in the Universe

Comets May Be Site of RNA World or

Iron-Sulfur World and the Origin of Life

Hot/Cold Cycling as Comet Tumbles near PerihelionHot/Cold Cycling as Comet Tumbles near Perihelion

Rapid Evaporation when Internal Pressures Destroy CrustRapid Evaporation when Internal Pressures Destroy Crust

Water, H, C, O, N, P, S, Fe, Ni, Pyrite, Water, H, C, O, N, P, S, Fe, Ni, Pyrite, MontmorillioniteMontmorillionite

and Host of Organic Molecules Exist in CI1 and Host of Organic Molecules Exist in CI1

Carbonaceous Meteorites and Hence Cometary NucleiCarbonaceous Meteorites and Hence Cometary Nuclei

Comets Mau Be Sites for Birth of Amino Acids, RNA World, Comets Mau Be Sites for Birth of Amino Acids, RNA World,

DNA, Origin of Life & Distribute Water, Biomolecules and DNA, Origin of Life & Distribute Water, Biomolecules and

Life Life ---- Spreading a Biosphere throughout the CosmosSpreading a Biosphere throughout the Cosmos

Life in the UniverseLife in the Universe

CONCLUSIONS Problems with Current Origin of Life Models Suggest Life Problems with Current Origin of Life Models Suggest Life

on Earth May Have Been Delivered to Early Earthon Earth May Have Been Delivered to Early Earth

Life Conditions (Water, Energy & Biogenic Elements) CoLife Conditions (Water, Energy & Biogenic Elements) Co--

Exist on All Comets, Planets & Moons of Solar SystemExist on All Comets, Planets & Moons of Solar System

Absence of Nitrogen Proves Fossils of Cyanobacteria, Absence of Nitrogen Proves Fossils of Cyanobacteria,

Acritarchs & Diatoms in Meteorites are IndigenousAcritarchs & Diatoms in Meteorites are Indigenous

Extraterrestrial Life Exists. Life on Earth May Have Formed Extraterrestrial Life Exists. Life on Earth May Have Formed

on Comets or on Comets or ExoPlanetsExoPlanets More Ancient than our Sun and More Ancient than our Sun and

Been Transported to Early Earth by Interstellar CometsBeen Transported to Early Earth by Interstellar Comets

Life in the UniverseLife in the Universe ACKNOWLEDGEMENTSACKNOWLEDGEMENTS

Electron Microscopy Electron Microscopy –– NASA/MSFC NASA/MSFC -- Gregory Jerman; Gregory Jerman; Cardiff Cardiff UnivUniv: : N. C. Wickramasinghe, N. C. Wickramasinghe, JINR: JINR: A A RyuminRyumin, Mikhail , Mikhail KapralovKapralov

Meteorite Samples Courtesy: Meteorite Samples Courtesy: Claude Claude PerronPerron & M. & M. RossignolRossignol--StrickStrick--MuseeMusee d’Histoired’Histoire NaturelleNaturelle de Parisde Paris; Emile ; Emile LadierLadier--MontaubanMontauban MuseumMuseum; P. ; P. SipieraSipiera Planetary Studies Foundation & Field Planetary Studies Foundation & Field Museum, ChicagoMuseum, Chicago; William Birch, ; William Birch, Victoria Museum, MelbourneVictoria Museum, Melbourne

Discussions of Meteoritics, Bacterial Paleontology and Cyanobacteria Discussions of Meteoritics, Bacterial Paleontology and Cyanobacteria --

Academician Alexei Yu. Rozanov, Astrobiology Sector, JINRAcademician Alexei Yu. Rozanov, Astrobiology Sector, JINR

Academician Eric Academician Eric GalimovGalimov, , VernadskyVernadsky Institute (RAS)Institute (RAS);; Rosemarie Rosemarie RippkaRippka--HerdmanHerdman -- InstitutInstitut Pasteur, ParisPasteur, Paris

Presentation Dedicated to the Memory of Academician Georgi Presentation Dedicated to the Memory of Academician Georgi Zavarzin and Zavarzin and LudmillaLudmilla GerassimenkoGerassimenko-- INMI (RAS) and David INMI (RAS) and David

GilichinskyGilichinsky, Inst. For Soil Science and Photosynthesis, , Inst. For Soil Science and Photosynthesis, PushchinoPushchino

Thank You for Your AttentionThank You for Your Attention