Editing Biosphere (section)

== Earth's biosphere ==
=== Overview ===
Currently, the total number of [[Cell (biology)|living cells]] on the Earth is estimated to be 10<sup>30</sup>; the total number since the beginning of Earth, as 10<sup>40</sup>, and the total number for the entire time of a [[Planetary habitability|habitable planet Earth]] as 10<sup>41</sup>.<ref name="NYT-20231201">{{cite news|last=Overbye|first=Dennis|author-link=Dennis Overbye|title=Exactly How Much Life Is on Earth? – According to a new study, living cells outnumber stars in the universe, highlighting the deep, underrated link between geophysics and biology.|url=https://www.nytimes.com/2023/12/01/science/space/earth-biology-life.html|date=1 December 2023|work=The New York Times|url-status=live|archive-url=https://archive.today/20231201065236/https://www.nytimes.com/2023/12/01/science/space/earth-biology-life.html|archive-date=1 December 2023|access-date=1 December 2023}}</ref><ref name="CB-20231106">{{cite journal|author=Crockford, Peter W.|display-authors=et al.|title=The geologic history of primary productivity|url=https://www.cell.com/current-biology/fulltext/S0960-9822(23)01286-1|date=6 November 2023|journal=[[Current Biology]]|volume=33|issue=21|pages=P7741–4750.E5|doi=10.1016/j.cub.2023.09.040|pmid=37827153|bibcode=2023CBio...33E4741C|archive-url=https://archive.today/20231201131033/https://www.cell.com/current-biology/fulltext/S0960-9822(23)01286-1|archive-date=1 December 2023|access-date=1 December 2023}}</ref> This is much larger than the total number of estimated stars (and Earth-like planets) in the observable universe as 10<sup>24</sup>, a number which is more than all the grains of beach sand on planet Earth;<ref name="ESA-2020">{{cite web|author=Staff|title=How many stars are there in the Universe?|url=https://www.esa.int/Science_Exploration/Space_Science/Herschel/How_many_stars_are_there_in_the_Universe|date=2020|work=[[European Space Agency]]|url-status=live|archive-url=https://archive.today/20200117184622/https://www.esa.int/Science_Exploration/Space_Science/Herschel/How_many_stars_are_there_in_the_Universe|archive-date=17 January 2020|access-date=January 17, 2020}}</ref><ref name="SWIN-20020201">{{cite web|last=Mackie|first=Glen|title=To see the Universe in a Grain of Taranaki Sand|url=https://astronomy.swin.edu.au/~gmackie/billions.html|date=1 February 2002|work=[[Swinburne University of Technology]]|url-status=live|archive-url=https://archive.today/20221228121404/https://astronomy.swin.edu.au/~gmackie/billions.html|archive-date=28 December 2022|access-date=1 December 2023}}</ref><ref name="CNET-20150319">{{cite news|last=Mack|first=Eric|title=There may be more Earth-like planets than grains of sand on all our beaches – New research contends that the Milky Way alone is flush with billions of potentially habitable planets -- and that's just one sliver of the universe.|url=https://www.cnet.com/science/the-milky-way-is-flush-with-habitable-planets-study-says/|date=19 March 2015|work=[[CNET]]|url-status=live|archive-url=https://archive.today/20231201144523/https://www.cnet.com/science/the-milky-way-is-flush-with-habitable-planets-study-says/|archive-date=1 December 2023|access-date=1 December 2023}}</ref><ref name="MNRAS-20150313">{{cite journal|last1=T. Bovaird|first1=T.|last2=Lineweaver|first2=C.H.|last3=Jacobsen|first3=S.K.|title=Using the inclinations of Kepler systems to prioritize new Titius–Bode-based exoplanet predictions|url=https://academic.oup.com/mnras/article/448/4/3608/970734|date=13 March 2015|journal=[[Monthly Notices of the Royal Astronomical Society]]|volume=448|issue=4|pages=3608–3627|doi=10.1093/mnras/stv221|url-status=live|archive-url=https://archive.today/20231201151205/https://academic.oup.com/mnras/article/448/4/3608/970734|archive-date=1 December 2023|access-date=1 December 2023|doi-access=free|arxiv=1412.6230}}</ref> but less than the total number of atoms estimated in the observable universe as 10<sup>82</sup>;<ref name="LS-20210711">{{cite news|last=Baker|first=Harry|title=How many atoms are in the observable universe?|url=https://www.livescience.com/how-many-atoms-in-universe.html|date=11 July 2021|work=[[Live Science]]|url-status=live|archive-url=https://archive.today/20231201143640/https://www.livescience.com/how-many-atoms-in-universe.html|archive-date=1 December 2023|access-date=1 December 2023}}</ref> and the estimated total number of stars in an [[Inflation (cosmology)|inflationary universe]] (observed and unobserved), as 10<sup>100</sup>.<ref name="SR-20200203">{{cite journal|last=Totani|first=Tomonori|title=Emergence of life in an inflationary universe|date=3 February 2020|journal=[[Scientific Reports]]|volume=10|number=1671|page=1671|doi=10.1038/s41598-020-58060-0|doi-access=free|pmid=32015390|pmc=6997386|arxiv=1911.08092|bibcode=2020NatSR..10.1671T}}</ref>

=== Age ===
[[File:Stromatolithe Paléoarchéen - MNHT.PAL.2009.10.1.jpg|thumb|200px|right|Stromatolite fossil estimated at 3.2–3.6 billion years old]]
The [[Earliest known life forms|earliest evidence]] for life on Earth includes [[Biogenic substance|biogenic]] [[graphite]] found in 3.7&nbsp;billion-year-old [[metasediment]]ary rocks from [[Western Greenland]]<ref name="NG-20131208">{{cite journal|title=Evidence for biogenic graphite in early Archaean Isua metasedimentary rocks|journal=[[Nature Geoscience]]|doi=10.1038/ngeo2025|date=8 December 2013|volume=7|issue=1|pages=25–28|bibcode=2014NatGe...7...25O|last1=Ohtomo|first1=Yoko|last2=Kakegawa|first2=Takeshi|last3=Ishida|first3=Akizumi|last4=Nagase|first4=Toshiro|last5=Rosing|first5=Minik T.}}</ref> and [[microbial mat]] [[fossils]] found in 3.48&nbsp;billion-year-old [[sandstone]] from [[Western Australia]].<ref name="AP-20131113">{{cite news|last=Borenstein|first=Seth|title=Oldest fossil found: Meet your microbial mom|url=http://apnews.excite.com/article/20131113/DAA1VSC01.html|date=13 November 2013|agency=Associated Press|access-date=15 November 2013|archive-url=https://web.archive.org/web/20150629230719/http://apnews.excite.com/article/20131113/DAA1VSC01.html|archive-date=29 June 2015|url-status=live}}</ref><ref name="AST-20131108">{{cite journal|last1=Noffke|first1=Nora|author1-link=Nora Noffke|last2=Christian|first2=Daniel|last3=Wacey|first3=David|last4=Hazen|first4=Robert M.|title=Microbially Induced Sedimentary Structures Recording an Ancient Ecosystem in the ca. 3.48 Billion-Year-Old Dresser Formation, Pilbara, Western Australia|date=8 November 2013|journal=[[Astrobiology (journal)|Astrobiology]]|doi=10.1089/ast.2013.1030|pmid=24205812|pmc=3870916|volume=13|issue=12|pages=1103–24|bibcode=2013AsBio..13.1103N}}</ref> More recently, in 2015, "remains of [[Biotic material|biotic life]]" were found in 4.1&nbsp;billion-year-old rocks in Western Australia.<ref name="AP-20151019">{{cite news|last=Borenstein|first=Seth|title=Hints of life on what was thought to be desolate early Earth|url=http://apnews.excite.com/article/20151019/us-sci--earliest_life-a400435d0d.html|date=19 October 2015|work=[[Excite (web portal)|Excite]]|location=Yonkers, NY|publisher=[[Mindspark Interactive Network]]|agency=Associated Press|url-status=dead|archive-url=https://web.archive.org/web/20181001171406/http://apnews.excite.com/article/20151019/us-sci--earliest_life-a400435d0d.html|archive-date=1 October 2018|access-date=8 October 2018}}</ref><ref name="PNAS-20151014-pdf">{{cite journal|last1=Bell|first1=Elizabeth A.|last2=Boehnike|first2=Patrick|last3=Harrison|first3=T. Mark|last4=Mao|first4=Wendy L.|display-authors=3|date=19 October 2015|title=Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon|journal=Proc. Natl. Acad. Sci. U.S.A.|doi=10.1073/pnas.1517557112|pmid=26483481|pmc=4664351|volume=112|issue=47|pages=14518–21|bibcode=2015PNAS..11214518B|doi-access=free}} Early edition, published online before print.</ref> In 2017, putative fossilized [[microorganism]]s (or [[Micropaleontology#Microfossils|microfossils]]) were announced to have been discovered in [[hydrothermal vent]] precipitates in the [[Nuvvuagittuq Greenstone Belt|Nuvvuagittuq Belt]] of Quebec, Canada that were as old as 4.28&nbsp;billion years, the oldest record of life on earth, suggesting "an almost instantaneous emergence of life" after [[Origin of water on Earth#History of water on Earth|ocean formation 4.4 billion years ago]], and not long after the [[Age of the Earth|formation of the Earth]] 4.54&nbsp;billion years ago.<ref name="NAT-20170301">{{cite journal|author=Dodd, Matthew S.|author2=Papineau, Dominic|author3=Grenne, Tor|author4=Slack, John F.|author5=Rittner, Martin|author6=Pirajno, Franco|author7=O'Neil, Jonathan|author8=Little, Crispin T. S.|title=Evidence for early life in Earth's oldest hydrothermal vent precipitates|journal=Nature|volume=343|issue=7643|pages=60–64|date=2 March 2017|doi=10.1038/nature21377|pmid=28252057|bibcode=2017Natur.543...60D|s2cid=2420384|url=http://eprints.whiterose.ac.uk/112179/1/ppnature21377_Dodd_for%20Symplectic.pdf|access-date=19 February 2019|archive-url=https://web.archive.org/web/20180723232142/http://eprints.whiterose.ac.uk/112179/1/ppnature21377_Dodd_for%20Symplectic.pdf|archive-date=23 July 2018|url-status=live|doi-access=free}}</ref><ref name="NYT-20170301">{{cite news|last=Zimmer|first=Carl|author-link=Carl Zimmer|title=Scientists Say Canadian Bacteria Fossils May Be Earth's Oldest|url=https://www.nytimes.com/2017/03/01/science/earths-oldest-bacteria-fossils.html|date=1 March 2017|work=The New York Times|access-date=2 March 2017|archive-url=https://web.archive.org/web/20170302042424/https://www.nytimes.com/2017/03/01/science/earths-oldest-bacteria-fossils.html|archive-date=2 March 2017|url-status=live}}</ref><ref name="BBC-20170301">{{cite web|last=Ghosh|first=Pallab|title=Earliest evidence of life on Earth 'found|url=https://www.bbc.co.uk/news/science-environment-39117523|publisher=BBC News|date=1 March 2017|access-date=2 March 2017|archive-url=https://web.archive.org/web/20170302002134/http://www.bbc.co.uk/news/science-environment-39117523|archive-date=2 March 2017|url-status=live}}</ref><ref name="4.3b oldest">{{cite news|last1=Dunham|first1=Will|title=Canadian bacteria-like fossils called oldest evidence of life|url=http://ca.reuters.com/article/topNews/idCAKBN16858B?sp=true|date=1 March 2017|work=Reuters|access-date=1 March 2017|archive-url=https://web.archive.org/web/20170302114728/http://ca.reuters.com/article/topNews/idCAKBN16858B?sp=true|archive-date=2 March 2017|url-status=dead}}</ref> According to biologist [[Stephen Blair Hedges]], "If life arose relatively quickly on Earth ... then it could be common in the [[universe]]."<ref name="AP-20151019" />

=== Extent ===
[[File:Ruppelsvulture.jpg|thumb|upright|Rüppell's vulture]]
[[File:XenophyophoreNOAA.jpg|thumb|[[Xenophyophore]], a barophilic organism, from the [[Galápagos hotspot|Galapagos Rift]]]]
Every part of the planet, from the [[polar region|polar]] ice caps to the [[equator]], features life of some kind. Recent advances in [[microbiology]] have demonstrated that microbes live deep beneath the Earth's terrestrial surface and that the total mass of [[microbial]] life in so-called "uninhabitable zones" may, in [[Biomass (ecology)|biomass]], exceed all animal and plant life on the surface. The actual thickness of the biosphere on Earth is difficult to measure. Birds typically fly at altitudes as high as {{convert|1800|m|ft mi|abbr=on}} and fish live as much as {{convert|8372|m|ft mi|abbr=on}} underwater in the [[Puerto Rico Trench]].<ref name="Campbell 2006" />

There are more extreme examples for life on the planet: [[Rüppell's vulture]] has been found at [[altitude]]s of {{convert|11300|m|ft mi|abbr=off}}; [[bar-headed goose|bar-headed geese]] migrate at altitudes of at least {{convert|8300|m|ft mi|abbr=on}}; [[yak]]s live at elevations as high as {{convert|5400|m|ft mi|abbr=on}} above sea level; [[mountain goat]]s live up to {{convert|3050|m|ft mi|abbr=on}}. Herbivorous animals at these elevations depend on lichens, grasses, and herbs.

Life forms live in every part of the Earth's biosphere, including [[soil]], [[hot spring]]s, [[endolith|inside rocks]] at least {{convert|12|mi|km|order=flip|abbr=on}} deep underground, and at least {{convert|40|mi|km|order=flip|abbr=on}} high in the atmosphere.<ref name="SD-19980625-UG">{{cite web|publisher=University of Georgia|title=First-Ever Scientific Estimate of Total Bacteria on Earth Shows Far Greater Numbers Than Ever Known Before|url=https://www.sciencedaily.com/releases/1998/08/980825080732.htm|date=25 August 1998|work=[[Science Daily]]|access-date=10 November 2014|archive-url=https://web.archive.org/web/20141110162101/https://www.sciencedaily.com/releases/1998/08/980825080732.htm|archive-date=10 November 2014|url-status=live}}</ref><ref name="ABM-20150112">{{cite web|last=Hadhazy|first=Adam|title=Life Might Thrive a Dozen Miles Beneath Earth's Surface|url=http://www.astrobio.net/extreme-life/life-might-thrive-dozen-miles-beneath-earths-surface/|date=12 January 2015|work=[[Astrobiology Magazine]]|access-date=11 March 2017|archive-url=https://web.archive.org/web/20170312065614/http://www.astrobio.net/extreme-life/life-might-thrive-dozen-miles-beneath-earths-surface/|archive-date=12 March 2017|url-status=usurped}}</ref><ref name="BBC-20151124">{{cite web|last=Fox-Skelly|first=Jasmin|title=The Strange Beasts That Live in Solid Rock Deep Underground|url=http://www.bbc.com/earth/story/20151124-meet-the-strange-creatures-that-live-in-solid-rock-deep-underground|date=24 November 2015|publisher=[[BBC Online]]|access-date=11 March 2017|archive-url=https://web.archive.org/web/20161125013248/http://www.bbc.com/earth/story/20151124-meet-the-strange-creatures-that-live-in-solid-rock-deep-underground|archive-date=25 November 2016|url-status=live}}</ref> Marine life under many forms has been found in the deepest reaches of the [[world ocean]] while much of the [[deep sea]] remains to be explored.<ref>{{cite journal |last1=Briand |first1=F. |last2=Snelgrove |first2=P. |date=2003 |title=Mare Incognitum? An overview |journal=CIESM Workshop Monographs |volume=23 |pages=5–27}}[https://www.researchgate.net/publication/365871261]</ref>

Under certain test conditions, microorganisms have been observed to [[Panspermia#Research in outer space|survive the vacuum of outer space]].<ref name=Dose>{{cite journal|title=ERA-experiment "space biochemistry"|journal=Advances in Space Research|first1=K. Dose|author2=A. Bieger-Dose|author3=R. Dillmann|author4=M. Gill|author5=O. Kerz|others=A. Klein, H. Meinert, T. Nawroth, S. Risi, C. Stride|volume=16|issue=8|year=1995|pages=119–129|doi=10.1016/0273-1177(95)00280-R|last1=Zhang|pmid=11542696|bibcode=1995AdSpR..16h.119D}}</ref><ref name='Horneck'>{{cite journal|title=Biological responses to space: results of the experiment "Exobiological Unit" of ERA on EURECA I|journal=Adv. Space Res.|year=1995|author1=Horneck G|author2=Eschweiler U|author3=Reitz G|author4=Wehner J|author5=Willimek R|author6=Strauch K.|volume=16|issue=8|pages=105–18|pmid=11542695|bibcode=1995AdSpR..16h.105H|doi=10.1016/0273-1177(95)00279-N}}</ref> The total amount of soil and subsurface bacterial [[carbon]] is estimated as 5&nbsp;×&nbsp;10<sup>17</sup>&nbsp;g.<ref name="SD-19980625-UG" /> The mass of [[prokaryote]] microorganisms—which includes bacteria and archaea, but not the nucleated [[Microorganism#Eukaryotes|eukaryote microorganisms]]—may be as much as 0.8&nbsp;trillion tons of carbon (of the total biosphere [[Biomass (ecology)|mass]], estimated at between 1 and 4&nbsp;trillion tons).<ref name="AGCI-2014">{{cite web|author=Staff|title=The Biosphere|url=http://www.agci.org/classroom/biosphere/index.php|date=2014|publisher=[[The Given Institute|Aspen Global Change Institute]]|access-date=10 November 2014|archive-url=https://web.archive.org/web/20141110164609/http://www.agci.org/classroom/biosphere/index.php|archive-date=10 November 2014|url-status=live}}</ref> [[Piezophile|Barophilic]] marine microbes have been found at more than a depth of {{convert|10000|m|ft mi|abbr=on}} in the [[Mariana Trench]], the deepest spot in the Earth's oceans.<ref>{{cite journal|last1=Takamia|display-authors=etal|year=1997|title=Microbial flora in the deepest sea mud of the Mariana Trench|journal=FEMS Microbiology Letters|volume=152|issue=2|pages=279–285|doi=10.1111/j.1574-6968.1997.tb10440.x|pmid=9231422|doi-access=free}}</ref> In fact, single-celled life forms have been found in the deepest part of the Mariana Trench, by the [[Challenger Deep]], at depths of {{convert|11034|m|ft mi|abbr=on}}.<ref>{{Cite web|url=http://news.nationalgeographic.com/news/2005/02/0203_050203_deepest.html|title=National Geographic, 2005|access-date=2012-12-18|archive-url=https://web.archive.org/web/20120822121902/http://news.nationalgeographic.com/news/2005/02/0203_050203_deepest.html|archive-date=2012-08-22|url-status=dead}}</ref><ref name="LS-20130317">{{cite web|last=Choi|first=Charles Q.|title=Microbes Thrive in Deepest Spot on Earth|url=http://www.livescience.com/27954-microbes-mariana-trench.html|date=17 March 2013|publisher=[[LiveScience]]|access-date=17 March 2013|archive-url=https://web.archive.org/web/20130402234623/http://www.livescience.com/27954-microbes-mariana-trench.html|archive-date=2 April 2013|url-status=live}}</ref><ref name="NG-20130317">{{cite journal|last1=Glud|first1=Ronnie|last2=Wenzhöfer|first2=Frank|last3=Middelboe|first3=Mathias|last4=Oguri|first4=Kazumasa|last5=Turnewitsch|first5=Robert|last6=Canfield|first6=Donald E.|last7=Kitazato|first7=Hiroshi|title=High rates of microbial carbon turnover in sediments in the deepest oceanic trench on Earth|doi=10.1038/ngeo1773|date=17 March 2013|journal=[[Nature Geoscience]]|volume=6|issue=4|pages=284–288|bibcode=2013NatGe...6..284G}}</ref> Other researchers reported related studies that microorganisms thrive inside rocks up to {{convert|580|m|ft mi|abbr=on}} below the sea floor under {{convert|2590|m|ft mi|abbr=on}} of ocean off the coast of the [[northwestern United States]],<ref name="LS-20130317" /><ref name="LS-20130314">{{cite web|last=Oskin|first=Becky|title=Intraterrestrials: Life Thrives in Ocean Floor|url=http://www.livescience.com/27899-ocean-subsurface-ecosystem-found.html|date=14 March 2013|publisher=[[LiveScience]]|access-date=17 March 2013|archive-url=https://web.archive.org/web/20130402235647/http://www.livescience.com/27899-ocean-subsurface-ecosystem-found.html|archive-date=2 April 2013|url-status=live}}</ref> as well as {{convert|2400|m|ft mi|abbr=on}} beneath the seabed off Japan.<ref name="BBC-20141215-RM">{{cite news|last=Morelle|first=Rebecca|author-link=Rebecca Morelle|title=Microbes discovered by deepest marine drill analysed|url=https://www.bbc.com/news/science-environment-30489814|date=15 December 2014|publisher=BBC News|access-date=15 December 2014|archive-url=https://web.archive.org/web/20141216185424/http://www.bbc.com/news/science-environment-30489814|archive-date=16 December 2014|url-status=live}}</ref> Culturable thermophilic microbes have been extracted from cores drilled more than {{convert|5000|m|ft mi|abbr=on}} into the [[Earth's crust]] in [[Sweden]],<ref name="Szewzyketal1994">{{cite journal|last1=Szewzyk|first1=U|last2=Szewzyk|first2=R|last3=Stenstrom|first3=TR.|year=1994|title=Thermophilic, anaerobic bacteria isolated from a deep borehole in granite in Sweden|journal=Proceedings of the National Academy of Sciences of the USA|volume=91|issue=5|pages=1810–1813|doi=10.1073/pnas.91.5.1810|pmid=11607462|pmc=43253|bibcode=1994PNAS...91.1810S|doi-access=free}}</ref> from rocks between {{convert|65-75|°C|°F|abbr=on}}. Temperature [[geothermal gradient|increases with increasing depth]] into the Earth's crust. The rate at which the temperature increases depends on many factors, including the type of crust (continental vs. oceanic), rock type, geographic location, etc. The greatest known temperature at which microbial life can exist is {{convert|122|°C|°F|abbr=on}} (''[[Methanopyrus kandleri]]'' Strain 116). It is likely that the limit of life in the "[[deep biosphere]]" is defined by temperature rather than absolute depth.{{citation needed|date=January 2016}} On 20 August 2014, scientists confirmed the existence of microorganisms living {{convert|800|m|ft mi|abbr=on}} below the ice of [[Antarctica]].<ref name="NAT-20140820">{{cite journal|last=Fox|first=Douglas|title=Lakes under the ice: Antarctica's secret garden|date=20 August 2014|journal=[[Nature (journal)|Nature]]|volume=512|issue=7514|pages=244–246|doi=10.1038/512244a|bibcode=2014Natur.512..244F|pmid=25143097|doi-access=free}}</ref><ref name="FRB-20140820">{{cite web|last=Mack|first=Eric|title=Life Confirmed Under Antarctic Ice; Is Space Next?|url=https://www.forbes.com/sites/ericmack/2014/08/20/life-confirmed-under-antarctic-ice-is-space-next/|date=20 August 2014|work=[[Forbes]]|access-date=21 August 2014|archive-url=https://web.archive.org/web/20140822002442/http://www.forbes.com/sites/ericmack/2014/08/20/life-confirmed-under-antarctic-ice-is-space-next/|archive-date=22 August 2014|url-status=live}}</ref>

Earth's biosphere is divided into several [[biome]]s, inhabited by fairly similar [[flora (plants)|flora]] and [[fauna (animals)|fauna]]. On land, biomes are separated primarily by [[latitude]]. Terrestrial biomes lying within the [[Arctic Circle|Arctic]] and [[Antarctic Circle]]s are relatively barren of [[plant]] and [[animal]] life. In contrast, most of the more populous biomes lie near the [[equator]]. <!---Terrestrial organisms in temperate and Arctic biomes have relatively small amounts of total biomass, smaller energy requirements, and display prominent adaptations to cold, including world-spanning migrations, social adaptations, [[homeothermy]], [[estivation]] and multiple layers of insulation.--->

=== Annual variation ===
[[File:Mollweide Cycle.gif|center|660px|On land, vegetation appears on a scale from brown (low vegetation) to dark green (heavy vegetation); at the ocean surface, phytoplankton are indicated on a scale from purple (low) to yellow (high). This visualization was created with data from satellites including SeaWiFS, and instruments including the NASA/NOAA Visible Infrared Imaging Radiometer Suite and the Moderate Resolution Imaging Spectroradiometer.]]