I get the impression you don't know a lot about DNA and evolution.
Your DNA is made of non-coding regions interspersed with coding regions, which are the genes. Each gene produces a gene product (ignoring alternative splicing for the moment!), which usually is a protein. Some of these proteins are the proteins we usually think of, like enzymes. However, a great number of them have their role in interacting with the DNA to cause certain genes to either be transcribed to RNA more often or to be transcribed less often.
If you got a group of people and looked at the DNA sequences for one of their genes, you would find that they weren't all alike. Probably a few people would share one sequence, a few would share a different one, and then others would have a third variant. Each variant sequence for the gene is called an allele. Most genes have multiple possible alleles. New alleles arise through mutation of existing ones.
It is also possible to add new genes. There are several mechanisms for doing this. One of the most common is duplication--a region of the DNA is accidentally duplicated, usually leaving a copy of the gene next to the old gene. When this happens there are two copies of the gene, and one of the copies can then mutate freely and in the end produce a product with an entirely different function than the parent gene. We can see this with the HOX genes and hemoglobin family, for example.
In order to produce the protein product, the DNA is first transcribed into RNA. Then the RNA is translated into a protein. Each triplet of bases codes for one amino acid, and there is a lot of redundancy in the code. Because of this a mutation doesn't necessarily change the protein product at all. Many mutations are silent. Others are harmful, and others are beneficial.
So once again, if we don't become extinct we will eventually evolve into something else. However, it's hard to say what that might be without being able to see millions of years into the future.
What proof the there that it takes millions of years to evolve into something else? Is there any record of this happening?