What are the benefits to having introns?

The exact function of intron is yet unknown and they are usually considered junk segments of DNA. However, it has been observed that removal of introns from the native DNA sequence and then allowing its transcription does not facilitate the proper transcription of the region.

As a first approximation, it is possible to view introns as unimportant sequences whose only function is to be removed from an unspliced precursor RNA in order to generate the functional mRNA, rRNA or tRNA product. However, recent studies show that this perspective is, in many cases, overly simplistic. It is now well-established that some introns themselves encode specific proteins or can be further processed after splicing to generate noncoding RNA molecules. Alternative splicing is widely used to generate multiple proteins from a single gene. Furthermore, some introns represent mobile genetic elements and may be regarded as examples of selfish DNA.