In evolution, most genes survive and spread within populations because they increase the ability of their hosts (or their close relatives) to survive and reproduce. But some genes spread in spite of being harmful to the host organism--by distorting their own transmission to the next generation, or by changing how the host behaves toward relatives. As a consequence, different genes in a single organism can have diametrically opposed interests and adaptations. Covering all species from yeast to humans, Genes in Conflict is the first book to tell the story of selfish genetic elements,...