On the Origin of Species to be expanded with his research results and published if he died prematurely. In November 1844, the anonymously published popular science book "Vestiges of the Natural History of Creation", written by Scottish journalist Robert Chambers, widened public interest in the concept of transmutation of species. "Vestiges" used evidence from the fossil record and embryology to support the claim that living things had progressed from the simple to the more complex over time. But it proposed a linear progression rather than the branching common descent theory behind Darwin's work in progress, and it ignored adaptation. Darwin read it soon after publication,
On the Origin of Species America, Africa, and Australia all have regions with similar climates at similar latitudes, but those regions have very different plants and animals. The species found in one area of a continent are more closely allied with species found in other regions of that same continent than to species found on other continents. Darwin noted that barriers to migration played an important role in the differences between the species of different regions. The coastal sea life of the Atlantic and Pacific sides of Central America had almost no species in common even though the Isthmus of Panama was only a few