This book presents a hypothesis and evidence that organisms promote and ecosystems maximize biodiversity. All species have a net positive effect on their environment, other species, and diversity. The sun is 30% hotter than when life began, but the temperature has been kept moderate by life. Life created high oxygen, the ozone layer, and fertile soil, a diverse, living system. No species evolves in isolation, and most evolution is coevolution. The nature and number of links between species are as important as species number. Eukaryotes coevolve with complex ecosystems of microbes with which they exchange genes. Genomes and intraspecific interactions both act to promote evolution and diversification. Viruses increase diversity of their hosts and cause macroevolutionary transitions. Key Features Life alters the Earth in ways that increase biodiversity All species make their environment better for other species and promote diversity Life created the life-friendly atmosphere, temperature, and soil of today
