How is evolution important in explaining the diversity of life?

Evolution explains how new biological species arise. This
happen when  a change in the gene pool of a population has taken place. A population is
a group of reproductively isolated organisms that interbreed or have the potential to
interbreed. Evolution explains how certain conditions such as natural selection, choice
of mate, , food preference, mutation, can cause a population not to be able to
interbreed succesfully, and eventually become a separate
species.

Recent studies claimed that a type of fruit fly
called, Rhagoleitis pomonella might be currently undergoing sympatric speciation (new
species arise from single population without geographical barrier). This type of fruit
fly, originally feed on the fruits of hawthorn trees, but began to feed on apples. This
apple maggot no longer feed on hawthorn fruits and its ancestor maggot does not feed on
apples. Geneticist believed that is an example of sympatric speciation (new species
arise from single population without geographical
barrier).

Another example is the new plant species
produced by Georgii Karpechenko after crossing a cabbage with a radish. The plant
produced from these unrelated species could only breed with each other but not with
either the cabbage and radish ancestors.