Editing Nature (section)

===Microbes===
[[File:Yellow mite (Tydeidae) Lorryia formosa 2 edit.jpg|thumb|upright|A microscopic mite [[Mite|''Lorryia formosa'']]]]
{{Main|Microbe}}
The first form of life to develop on the Earth were [[unicellular]], and they remained the only form of life until about a billion years ago when multi-cellular organisms began to appear.<ref>{{cite journal |
author = Schopf J|title = Disparate rates, differing fates: tempo and mode of evolution changed from the Precambrian to the Phanerozoic|journal = Proc Natl Acad Sci USA|volume = 91|issue = 15|pages = 6735–42|date = 1994|pmid = 8041691|doi = 10.1073/pnas.91.15.6735 |
pmc = 44277
|bibcode = 1994PNAS...91.6735S|doi-access = free}}</ref> Microorganisms or microbes are [[microscopic]], and smaller than the human eye can see.<ref>{{Britannica URL |dictionary/microorganism|Microorganism}}</ref> [[Microorganism]]s can be [[single-celled]], such as [[Bacteria]], [[Archaea]], many [[Protist]]a, and a minority of [[Fungus|Fungi]].<ref>{{cite web|url=https://www.biologyonline.com/dictionary/unicellular|title=Unicellular|work= BiologyOnline.com | access-date=5 August 2008}}</ref>

These life forms are found in almost every location on the Earth where there is liquid water, including in the Earth's interior.<ref>{{cite journal|author = Szewzyk U|author2 = Szewzyk R|author3 = Stenström T|title = Thermophilic, anaerobic bacteria isolated from a deep borehole in granite in Sweden|doi= 10.1073/pnas.91.5.1810|journal = Proc Natl Acad Sci USA|volume = 91|issue = 5|pages = 1810–1813|date = 1994|pmid = 11607462|pmc = 43253|bibcode = 1994PNAS...91.1810S|doi-access = free}}</ref>
Their reproduction is both rapid and profuse. The combination of a high mutation rate and a [[horizontal gene transfer]]<ref>{{cite journal|author = Wolska K|title = Horizontal DNA transfer between bacteria in the environment|journal = Acta Microbiol Pol|volume = 52|issue = 3|pages = 233–243|date = 2003|pmid = 14743976}}</ref> ability makes them highly adaptable, and able to survive in new and sometimes very harsh environments, including [[outer space]].<ref>{{cite journal|author = Horneck G|title = Survival of microorganisms in space: a review|journal = Adv Space Res|volume = 1|issue = 14|pages = 39–48|date = 1981|pmid = 11541716|doi = 10.1016/0273-1177(81)90241-6}}</ref> They form an essential part of the planetary ecosystem. However, some microorganisms are [[pathogen]]ic and can post health risk to other organisms.

[[Virus|Viruses]] are [[pathogen|infectious agents]], but they are not autonomous [[Outline of life forms|life forms]], as it is the case for [[viroid|viroids]], [[satellite (biology)|satellites]], [[Defective interfering particle|DPIs]] and [[prion|prions]].<ref name="Solomon">{{cite book|last1=Solomon|first1=Eldra|last2=Martin |first2=Charles |last3=Martin |first3=Diana W. |last4=Berg |first4=Linda R. |title=Biology |date=2019|publisher=[[Cengage Learning]]|isbn=978-1305179899|pages=408, 420–422}}</ref>