How much of the human genome is functional? This a problem that will be solved by biochemists not epistemologists.

What is Junk DNA? What is functional DNA? Defining your terms is a key part of any scientific controversy because you can't have a debate if you can't agree on what you are debating. We've been debating the prevalence of Junk Dna for more than 50 years and much of that debate has been (deliberately?) muddled by one side or the other in order to score points. For example, how many times have you heard the ridiculous claim that all noncoding DNA was supposed to be junk DNA? And how many times have you heard that all transcripts must have a function merely because they exist?