The mitochondria and chloroplast are thought to have once been free-living prokaryotes that were engulfed by an early eukaryote and incorporated into the functioning of that cell. For this discussion, describe the theory of endosymbiosis in your own words and identify and discuss one line the evidence for this theory. You can use your textbook as a reference and research this theory online as well. For full credit, I will be looking for unique thoughts (compared to other classmate submissions) on the evidence for the theory of endosymbiosis and your interaction with classmates.