The rest is "genetic garbage" accumulated in the course of evolution. Scientists have established that only 8.2% of genes carry useful information, important for human existence, the rest can be called a ballast.
The evolution continues today. Man acquires new variations of genes, old it is nowhere to disappear. One theory is that cell mitochondria were once separate cells, which is why they contain their genetic material.
In the course of evolution many species were formed from the same ancestor. Information about the distant past is recorded in DNA. In humans, it takes more than 90% of all genetic information. Only 1% of DNA is engaged in the encoded proteins, 7% control the encoding process.
However, even for 8.2% of the total DNA unbearable task for deciphering modern science. Important genetic material is 250 million base pairs, each of which something encodes.