What is the endosymbiont hypothesis and its evidence regarding historyof life on earth

Expert Answers
crmhaske eNotes educator| Certified Educator

The endosymbiotic hypothesis suggests that life on Earth evolved from the symbioses of single-celled organisms.  The evidence for this is largely taken from the observation that many of the building blocks of organic matter are composed of single-celled organisms that also exist independently, and that these independently existing single-celled organisms, usually in the form of bacteria, contain their own DNA.  Even when they exist internal to organic matter their genetic makeup is not completely the same as the cell they inhabit.  Furthermore, when the single-celled organisms are artificially separated from their symbiotic hosts, the host cell is unable to reproduce them; therefore, they had to have originated elsewhere.