Geographical spread coverage of living organism shows a lot of weird things that can be explained well as a result of evolution. Darwin noted that some animal found in Galapagos island looked like with the animals living in south America. The condition shows that the animals he found in Galapagos were the result of evolution from the animal that came from South America.
The weird spread patterns can be explained by the assumption That every species is inherited from the ancestors who naturally live in the continent. Moreover, the following generations spread to suitable habitat. The animal spread will stop when it come across barrier in the continent. The spread of terrestrial animal is blocked by sea so that the species will have geographical isolation. The isolated animals will mate to each other and produced individuals that are able to adapt certain environmental condition.
Source: Biology, Evolution Indicator