This book covers the many ways humans benefit from interactions with other living species. By studying animals of all kinds and sizes, from microbial organisms to elephants and whales, we can learn about their adaptations to extreme conditions on the planet Earth, about the evolutionary development of specialized capabilities, and about their ways of defending themselves against predators and diseases. The authors discuss the strengths and weaknesses of Homo sapiens, and how the study of animals can make us stronger and healthier. To deepen our knowledge of genetics, molecular and cell biology, physiology and medicine, we need to study model organisms. To cure human disease, we can learn from animals how they have evolved ways to protect themselves. To improve human performance, we can study the animal kingdom's top performers and learn from their successes. Considering these important pointers, the authors review genetic engineering techniques that can translate our existing and future animal connections into benefits for human health and performance.