Reactions to On the Origin of Species man to be envious of a naturalist like myself, immeasurably his inferior!" Darwin's had estimated that erosion of the Weald would take 300 million years, but in the second edition of "On the Origin of Species" published on 7 January 1860 he accepted that it would be safer to allow 150 million to 200 million years. Geologists knew the earth was ancient, but had felt unable to put realistic figures on the duration of past geological changes. Darwin's book provided a new impetus to quantifying geological time. His most prominent critic, John Phillips, had investigated how temperatures increased with depth
Genetics and the Origin of Species variation would allow populations to evolve rapidly as environmental conditions change. This book was a landmark in the evolutionary synthesis, as it presented the union of Mendelian genetics and Darwinian theory. In "Genetics and the Origin of Species", polyploidy is considered as a type of mutation. Polyploid cells have a chromosome number that is more than twice the haploid number. The effects of polyploidy between two different species causes hybridization and even greater evolution. Natural selection in an environment produces reproductive success, which benefits the species. Speciation is a process of evolution through which new biological species are formed. Dobzhansky