Evolution is a gradual steady process where organism moves form simpler to complex form. Biological evolution is ongoing changing process where organism fitter to its surroundings and transfer that characteristics to its next generation. Connecting link is those organism conjunct to or more taxonomic group and having characteristics of both related group. It revealed that in course of evolution the single or few species are middle within which provide a linkage between them. Connecting link and missing link are more or less similar but slightly difference, connecting links are live adjoining group of species while missing links are dead and fossilized. As for example, Peripatus is connecting link between Annelids and Arthropods, but Archaeopteryx is a missing link between Reptile and Aves. In this book we describe the basic of evolution, natural selection, various connecting and missing link in animal kingdom and their brief notes, and also evolution of modern man, etc. We clarified our description with additional notes and try our best for better understanding. It is a reckoner guide book on evolution, connecting and missing link.
