On the Origin of Species by Alfred Russel Wallace, claimed that patterns in the geographical distribution of living and fossil species could be explained if every new species always came into existence near an already existing, closely related species. Charles Lyell recognised the implications of Wallace's paper and its possible connection to Darwin's work, although Darwin did not, and in a letter written on 1–2 May 1856 Lyell urged Darwin to publish his theory to establish priority. Darwin was torn between the desire to set out a full and convincing account and the pressure to quickly produce a short paper. He met Lyell, and in
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