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
Reactions to On the Origin of Species example and Ramsay's data in chapter 9 of "On the Origin of Species" to estimate that erosion of the Weald's layered dome of Lower Cretaceous rocks “must have required 306,662,400 years; or say three hundred million years“. The "necessary corrections" Darwin made to his drafts for the second edition of the "Origin" were based on comments from others, particularly Lyell, and added a caveat suggesting a faster rate of erosion of the Weald: "perhaps it would be safer to allow two or three inches per century, and this would reduce the number of years to one hundred and fifty or