Many people have a vague sense that the hypothesized origin of life, in the form of bacteria, sounds plausible. However, few people can fathom how the first eukaryotic cell, complete with nucleus, mitochondria and maybe chloroplast, came into being. This book presents the evidence that reveals the origins of all three DNA-containing organelles. In addition, this book will illustrate how DNA, a molecule that is 2 meters (6 feet) long, can fit into all cells’ nuclei that are only about 2 microns (0.000002 meters) in diameter. Once eukaryotes evolved, the next obvious question is how multicellular organism could have evolved from simpler unicellular species. This book looks at multicellular algae as a case study on the origins of multicellularity.