Robert Callow & Laurence M Cook 
Genetic and Evolutionary Diversity [PDF ebook] 
The Sport of Nature

This book examines the causes of genetic diversity within and between populations, species formation and multiplication and the association of species in communities. It also discusses reproductive patterns in relation to the integrated control of breeding systems and chromosomes behaviour. The ideas presented link fields of biology usually treated separately, which are relevant to population genetic, cytogenetic , ecological and evolutionary studies.This revised edition includes significant advances in the fields of plant genetics and cytogenetics and a greater emphasis on long term evolutionary processes.