Ba a bayyana canje-canje a cikin morphology ko tsarin salula a cikin wadannan kwayoyin ba a cikin shekaru biliyan na gaba. Kwayoyin eukaryotic sun bayyana tsakanin 1.6 zuwa 2.7 biliyan shekaru da suka wuce. Babban canji na gaba a cikin tsarin tantanin halitta ya zo ne lokacin da kwayoyin cuta suka mamaye kwayoyin eukaryotic, a cikin wata ƙungiya mai haɗin gwiwa da ake kira endosymbiosis. Kwayoyin da aka mamaye da kwayar mai karɓar sun sami nasarar coevolution, tare da kwayoyin sun samo asali a cikin ko dai mitochondria ko hydrogenosomes. Wani mamayewa na cyanobacterial-kamar kwayoyin halitta ya haifar da samuwar chloroplasts a cikin algae da tsire-tsire. Tarihin rayuwa shine cewa unicellular eukary eukaryotes, prokaryotes da arthropods sun bayyana kimanin shekaru 610 da suka wuce lokacin da wadannan kwayoyin halitta suka fara bayyana a cikin yanayi na zamani har zuwa shekaru biliyan da suka gabata.
su ne mafi yawan dabbobi.