Amagciwane yizinto ezincane kakhulu okukholelwa ukuthi kube ukuphela kwendlela yokuphila eMhlabeni iminyaka eyizigidi eziyizinkulungwane ezimbili. Ukutholakala kwayo kutholwa u-Anton van Leeuwenhoek, usosayensi wase-Dutch wekhulu le-2.000.
Ama-prokaryote, okungukuthi, ayinayo i-nucleus yeseli echaziwe, nobukhulu bayo buba phakathi kwama-micrometer ayi-0,5 no-5, yize sibonga ama-microscopes kungabonwa ngokuningiliziwe, kanye nezinhlobo ezahlukahlukene ezisebenzisayo: izigaba, izinduku, izikhonkwane zikakhokho neziphephela.
Zake zaba ngaphansi kombuso wezilwane, kodwa kamuva zabekwa embusweni ozimele, obizwa ngokuthi yi-monera. Ucwaningo lwayo luhambisana ne-bacteriology, isayensi eyaqala ukuthuthuka ngasekupheleni kwekhulu leshumi nesishiyagalolunye ngenxa yocwaningo lwezokwelapha nezinqubo zokuvutshelwa, ikakhulukazi lezo zikaLouis Pasteur noRobert Koch.
Amagciwane hlala kuzo zonke izinto eziphilayo, kanye nakuzo zonke izizinda zomhlaba, kusukela ekujuleni kolwandle kuya entabeni ephakeme kakhulu, ngenxa yokuthi zivumelana kalula nanoma yisiphi isimo semvelo. Kulinganiselwa ukuthi kunamagciwane amaningi eMhlabeni kunanoma yiluphi olunye uhlobo lwezinto eziphilayo. Kuphela kugremu elilodwa lomhlabathi ovundile, amakhophi ayizigidi eziyizinkulungwane ezingama-2,5 angafinyelelwa.
Abantu futhi banamagciwane ahlala ngaphakathi kithi, ikakhulukazi esikhunjeni nasemgudwini wokugaya ukudla. Eminye iyazuzisa kanti leyo engavamisile ukwenziwa ize ngumthelela wokuvikela amasosha omzimba. Kodwa-ke akuhlali kunjalo. Amanye amabhaktheriya e-pathogenic angadala izifo kutheleleka okuyingozi kakhulu empilweni, njengasesimweni sekholera noma uchoko.