Branching Descent, is defined as a process by which new species originate from a single common descent.

Natural Selection is a process by which nature selects the favourable variation among the organisms produced due to mutation.

Natural Selection depends on the phrase “Survival of the Fittest”, thus due to the changes in the environmental conditions, it puts pressure on the organism which gives it chances either survives or disappears.

e.g. brown and white winged moths.