![Page 1: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/1.jpg)
1
The ~4 billion year co-evolution of Earth
and its Biosphere
Instructor: Carl B. Pilcher
OLLI at SSU
Life in the Universe: The Science of Astrobiology
Week 3—April 21, 2016
![Page 2: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/2.jpg)
SimonWilde,Cur/nUniv.,AustraliaandJohnValley,UniversityofWisconsin,Madison
TheJackHills,
WesternAustralia
![Page 3: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/3.jpg)
![Page 4: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/4.jpg)
Evidence from >4 BY-old zircons
Cavosie et al. 2005
Imaging U-Pb age
Oxygen isotopes
[Li] & Li isotopes
REEs, Ti Mineral inclusions
Slide courtesy John Valley
![Page 5: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/5.jpg)
Cool Early Earth?
5
Earth4.3BY
• 4.4 BY Protocontinental Crust • >4.3 BY End of Hadean • >3.5 BY Life >4.3 BY?
![Page 6: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/6.jpg)
Sunonly~75%asbrightastoday4billionyearsago.SowhatkepttheEarthwarmenoughforliquidwater?
FaintYoungSunParadox
Greenhouse gases!"
![Page 7: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/7.jpg)
Roughly30/mesmorepotentthancarbondioxide(CO2)asagreenhouse(heattrapping)gas
![Page 8: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/8.jpg)
The Universal"Tree of Life"(adapted from Pace;"Science 276, 734, 1997)"
Bacteria
Archaea
Eucarya
![Page 9: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/9.jpg)
Twopossibleearlymetabolisms
4H2+CO2CH4+2H2Omethanogenesis
H2+S0 H2Ssulfurrespira/on
Thesetwometabolismsarerelatedbiochemically:bothinvolvebreakingbondsbetweensulfuratoms
DidEarth’searliestlifestabilizethecondi=onsforitsownexistenceby
contribu=ngmethanetotheatmosphere?
hydrogencarbondioxidemethanewater
hydrogensulfurhydrogensulfide
Methanecanalsobeproducedabiologically,sowecan’tbesure.
![Page 10: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/10.jpg)
Earth’sHistory
CambrianExplosion
persistent
>
![Page 11: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/11.jpg)
11
History of Oxygen
Time before Present (billion yrs)!
P O2(a
tm)!
1!
0.1!
0.01!
0.001!
0.0001!
0.00001!4.5! 4! 3.5! 3! 2.5! 2! 1.5! 1! 0.5! 0!
Multi-cellular Life!
Prokaryotic Life!
First !Eukaryotic!
Life!
“Modern” O2!levels!
![Page 12: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/12.jpg)
Cyanobacteria
![Page 13: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/13.jpg)
Earth’sOceanComposi/onoverGeologicTime
AnbarandKnoll,Science297,1137(2002)
Fe2+
![Page 14: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/14.jpg)
![Page 15: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/15.jpg)
![Page 16: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/16.jpg)
Earth’sOceanComposi/onoverGeologicTime
AnbarandKnoll,Science297,1137(2002)
Fe2+
![Page 17: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/17.jpg)
Sulfur-bearingrocks
SulfateSO4
2-SulfidesH2S,HS-
Oxida/veweathering
Bacterialreduc/on
“Weathering”(erosionandchemicalaltera/on)ofsulfur-bearingrocksunderanoxygen-richatmosphere
Productsflowintooceans
Sulfate-reducingbacteria!
![Page 18: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/18.jpg)
Earth’sHistory
CambrianExplosion
persistent
>
![Page 19: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/19.jpg)
“Dridingcon/nents”~800millionyearsago
![Page 20: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/20.jpg)
Pangaea(~200millionyearsago)
![Page 21: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/21.jpg)
![Page 22: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/22.jpg)
Earth’sCrust
![Page 23: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/23.jpg)
Earth’sInteriorStructure
![Page 24: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/24.jpg)
PlateTectonics
![Page 25: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/25.jpg)
![Page 26: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/26.jpg)
Earth’sPlateBoundaries
![Page 27: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/27.jpg)
![Page 28: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/28.jpg)
TheCascades
![Page 29: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/29.jpg)
![Page 30: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/30.jpg)
![Page 31: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/31.jpg)
Carbonate-SilicateCycle
Organismsformingcarbonateshells,par/cularlypro/sts(single-celleukaryotes),playanessen/alroleincarbonaterockforma/on
![Page 32: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/32.jpg)
Carbonate-SilicateCycle
![Page 33: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/33.jpg)
M Vogt, Science 2015;350:1466-1468
![Page 34: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/34.jpg)
CarbonDioxideCycle(shortertermthermostat)
![Page 35: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/35.jpg)
Earth’sOceanComposi/onoverGeologicTime
AnbarandKnoll,Science297,1137(2002)
Fe2+
![Page 36: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/36.jpg)
SnowballEarth
SnowballEarthsarethoughttohaveoccurred2.2-2.4BYago,justaderthebuild-upofoxygeninEarth’satmosphere,and580-750millionyearsago,justbeforetheCambrianExplosionwhenlarge,diverse,morecomplexanimalsappearabruptlyinthefossilrecord.
![Page 37: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/37.jpg)
![Page 38: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/38.jpg)
MassEx/nc/ons
![Page 39: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/39.jpg)
Cretaceous-Ter/ary(K/T)Ex/nc/onEvent
![Page 40: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/40.jpg)
![Page 41: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/41.jpg)
CausesofMassEx/nc/ons
• Theother4majormassex/nc/ons,aswellassmallerex/nc/onevents,appearnottobeassociatedwithimpacts;thecausesappeartobegeological/biological.– Theex/nc/onsweregradualorepisodic,occurringoverhundredsofthousandstomillionsofyears.
– Therearefewifanyimpactscratersoftherightage.– Therearecrediblegeological/biologicalexplana/ons.
![Page 42: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/42.jpg)
ThePermian-Triassic(P/T)Ex/nc/on• The“motherofallex/nc/ons”
– ≤96%ofalloceanspeciesand~70%ofalllandspeciesdiedoff• TheSiberianfloodbasalterup/onscoincidedwiththeex/nc/ons.– Anarearoughlythesizeofthe48con/guousstateswascoveredwithlavatoanaveragedepthofaboutamileoverapproximatelyamillionyears
– Muchoftheerup/onoccurredthroughtheworld’slargestcoalbasin,probablyconver/ngmuchofthecoaltocarbondioxideandmethane,bothimportantgreenhousegases.
– Increasedatmospherictemperaturewouldleadtoincreasedrainfallandcon/nentalweathering,producingmoresulfaterunoffintotheoceans,returningtheoceanstemporarilytothesulfidiccondi/onsofthemid-Proterozoic.
D.H.Erwin,Ex=nc=on:HowLifeonEarthNearlyEnded250MillionYearsAgo,PrincetonUniv.Press,2006
![Page 43: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/43.jpg)
Conclusions• Earthhasbeenhabitableforatleast3.5-4billionyearsandperhapslonger,almostsinceitsforma/on4.54billionyearsago.
• AninterplayofgeologicalandbiologicalprocesseshasbeenresponsibleformaintainingEarth’shabitabilityoversuchalonginterval,despiteasubstan/alchangeinthebrightnessofthesun.
• Thecourseofbiologicalevolu/onhasbeenaffectedbytheinterplayofgeologicalandbiologicalforces.– Ifwecould“replaythetapeoflife”,itisveryunlikelythatwewouldreproducethesamehistoryoflifeonEarth.
S.J.Gould,WonderfulLife:TheBurgessShaleandtheNatureofHistory,Norton,1989
![Page 44: The ~4 billion year co-evolution of Earth and its Biosphere › exed › olli › docs › course-handouts › spring-2016 … · – If we could “replay the tape of life”, it](https://reader036.vdocuments.site/reader036/viewer/2022070806/5f0435487e708231d40cd8e5/html5/thumbnails/44.jpg)
44
Questions?
QUESTIONS?