I recall that Professor Kwang had observed amoebas that had cannibalized bacteria cells. The bacteria were slaughtering the amoebas, but somehow some survived. This particular group of amoebas contained bacteria that thrived inside it. Hence the name, endosymbiosis. However, this lucky group and it's offspring could not survive without bacteria.
In 1987, Professor Kwang Jeon of the University of Tennessee observed a number of amoebas (single-celled eukaryotes) that had ingested bacteria cells. The bacteria were killing off most of the amoebas, but a small number of the amoeba survived and returned to their normal modes. However, the invading bacteria were still present within surviving amoebas. Jeon continued to experiment with the amoebas and discovered that these surviving amoebas, and their offspring, could not survive without the bacteria. Jeon's discovery and experimentation proves it is possible for a cell to become dependent on an invading organism.
