by Lynn Margulis and Dorian Sagan

How did the amazing variety of species come into being? Darwin’s Origin of Species puts forth a theory of natural selection, but never tells how the variation was created upon which natural selection could work. Many people struggle to understand how the incredible variety of biodiversity can be explained solely by random point mutations. This book shows that random point mutations is not the whole answer. “We believe random mutation is wildly overemphasized as a source of hereditary variation,” write the authors. Instead, this book reveals an important and over overlooked mechanism that is essential for understanding evolution. This is the acquisition of genes, which is an essential aspect in the creation of evolutionary novelty. The authors write “We show that here that the major source of inherited variation is not random mutation. Rather the important transmitted variation that leads to evolutionary novelty comes from the acquisition of genomes.” I would substitute the word “genes” for genomes since many species arise without acquiring entire genomes.