Aging is a puzzle to solve. This process is traditionally studied in a couple of biological models like fruit flies, worms and mice. What all these species have in common is their fast aging. This is excellent for lab budgets. It is a great short-term strategy. Who has time to study species that live for decades? But lifespan differences among species are magnitudes of order larger than any lifespan variation achieved in the lab. This is the reason for which I studied countless information resources in an attempt to gather highly specialized research into one easy-to-follow book. I wanted to see the forest among the trees. I wanted to expose the aging gap between species in an easy-to-follow and logical sequence. This book is my attempt at doing just that. What are the mechanisms underlying the aging gap between species? I intentionally chose to write the answer to this question in plain English. Aging research is too important to hide it behind the closed doors of formal scientific jargon. This book could not have existed if green tea, libraries and the Internet were not invented. The amount of data I had to browse in order to keep the essential patterns is huge. Yet this book is not exhaustive. This is not a dry academic textbook. I tried to instill life in a topic that is hugely important for the extension of human lifespan. Only you can decide if I achieved this. Contents Finding the Forest Among the Trees Being Reliable Counts The Mathematics of Aging The Speed of Senescence Case Study: Aging in Fish How to Estimate Chronological Age Taking Life Slowly On Temperature and Aging Dormancy The Housekeeping Problem Case Study: Aging in Turtles Intracellular Junk Case Study: Aging in Crustaceans Extracellular Junk Case Study: Protein Quality Control The Sweet Poison Are Cell Membranes the Pacemakers of Metabolism? Could Reproduction Set up the Pacemaker of Senescence? The Segregation of Somatic and Germ Cells Clonal Senescence Versus Mechanical Senescence Same Species, Different Lifespans Case Study: Eusocial Species Case Study: Parasite/Free-Living Populations Case Study: Island Versus Inland Populations Hormones as Pacemakers of Senescence Case Study: Low Hormone Levels in Long-lived Rodents Is Aging a Form of Dehydration? The Immune Pacemaker of Senescence Innate Versus Adaptive Immunity Senescent Cells Case Study: Thymic Involution in Negligible Senescence Species Reverse Engineering the Body Case Study: Why Are Sponges Potentially Immortal? Modular Growth and Aging Case Study: Youth Is Forever Gone. Unless You Are a Hydra. Or an Immortal Jellyfish Down The Neoteny Lane Case Study: Neoteny in Amphibians Case Study: Neoteny in Mammals It's All About Neoteny Does Aging Start When Growth Stops? Case Study: Indeterminate Growth in Crustaceans The Rate of Growth Case Study: Aging in Bivalves Is Telomerase The New Fountain of Youth? Case Study: Same Species, Different Telomerase Expression Telomerase Gene Therapy Case Study: Sea Urchins Perennial Plants and Their Regenerating Roots Case Study: The Bristlecone Pine Unitary Versus Colonial Organisms Cancer The Paradox of Peto Case Study: Cancer in Long-Lived Species The End Acknowledgments Bibliography