please explain the Branching Descent of darwin's theory.

According to the branching Descent theory of the Darwin all animals have originated from the common early descendent. This theory can be explained by the tree of life in which the first organism of particular class of organisms is at the base of the tree. The new species of organisms branch out from that organisms and these organisms when isolated geographically become so different that they result in the formation of the new species. Thus new species branch out from the single ancestor. This is referred to as the branching descent theory of Darwin.