The process of evolution of various species in certain geographical area beginning from a point & spreading or radiating to other geographical areas or habitats is remains as adaptive radiation. One of the best example of this phenomenon is that of Darwin's Finches.
Darwin observed many varieties of finches on the same island all of which have evolved on the island itself from original seed eating features. This has lead to many other forms with altered beaks, enabling them to become insectivorous and vegetarian finches, this process of evolution of different species in a given geographical area, starting from a point, and literally radiating to, other areas of geography is called adaptive radiation.
Another example = Australian Marsupials.
