The book “Organic Evolution”, with several novel features, is comprehensively written with latest advances in the subject and is divided in seven chapters. Chapter 1 of the book describes the environment of primitive earth and how it was essential for the origin of first life form. Chapter 2 includes evolutionary theories and supporting evidences in favour of evolution. The role of population genetics in evolution of gene pools of population is in Chapter 3. The concept of species and modes of speciation, how new species originates and how much genetic change is required for speciation is discussed in Chapter 4. Chapter 5 provides the essential information needed to understand molecular evolution and how molecules are reliable tools for molecular systematics and in reconstruction of phylogenies. Chapter 6 of the book describes vertebrate diversity and vertebrate evolution primarily focusing on Primates and the evolution of Homo sapiens. Finally, Chapter 7 is about the origin and evolution of Angiosperms. The language and contents of this book are made so simple and easy that even a student with a minimal knowledge of Life Sciences will be able to understand the essence of evolution.This book has been designed mainly to provide the most fundamental and updated knowledge of the subject to undergraduate and postgraduate students in various streams of Life Sciences- Botany, Zoology, Biotechnology, Microbiology, Biochemistry, Agriculture etc; of Indian Universities. Besides this book will be beneficial to student’s preparing for CSIR NET Life Sciences, GATE Life Sciences, ICMR Life Sciences, IAS, IFS and other State Civil service examinations.