Genetics and the Origin of Species natural selection, and speciation throughout his book to explain habits of populations and the resulting effects on their genetic behavior. The book explains evolution in depth as a process over time that accounts for the diversity of all life on Earth. The study of evolution was present, but greatly neglected at the time. Dobzhansky illustrates that evolution regarding the origin and nature of species during this time in history was deemed mysterious, but had expanding potential for progress to be made in its field. In Darwin's theory of natural selection, more organisms are produced than can survive. Some have variations
On the Origin of Species correspondence with Joseph Dalton Hooker affirmed that he did not want to expose his ideas to review by an editor as would have been required to publish in an academic journal. He began a "sketch" account on 14 May 1856, and by July had decided to produce a full technical treatise on species as his "big book" on "Natural Selection". His theory including the principle of divergence was complete by 5 September 1857 when he sent Asa Gray a brief but detailed abstract of his ideas. Darwin was hard at work on the manuscript for his "big book" on "Natural