Before the Human Genome Project (HGP) was completed, scientists expected that we would find about 100,000 genes coded for in our DNA. However, when the work was more or less completed in 2001, scientists had found only about 20,000 genes. Wow! This made the coding section at most about 2% of the more than 3 billion nucleotides in the genome. What was the rest of the DNA doing?
Many scientists insisted that the material that did not code for a gene (conferring information to form a protein) must in fact be useless junk DNA left over from a long period of evolution. However, studies on the whole genome, following the results of the ENCODE project and the HGP (human genome project) itself, have revealed that non-coding DNA is extremely important to our health. Thus, commentary in Nature in a section entitled “Not junk” declared: “Thanks in large part to the HGP, it is now appreciated that the majority of functional sequences in the human genome do not encode proteins. Rather, elements such as long non-coding RNAs, promoters, enhancers and countless gene-regulatory motifs work together to bring the genome to life.” [Nature. 2021. vol. 590 #7845 pp. 212-215. See p. 214].
More specific information on the significance of non-coding DNA has come from another 2021 article in Nature. Medical biotechnologists, who were researching limb malformations in people, found that deletion of a large chunk of long non-coding RNA (lncRNA) (which comes from the DNA) in the amount of 27,000 to 63,000 nucleotides (from human chromosome # 2) was directly connected to expression of the disability. If the non-coding DNA was not doing anything, it should not matter if or how much of it was lost. We see that this information further discredits the junk DNA interpretations. www.nature.com/articles/s41586-021-03208-9
Non-coding DNA does not code for proteins, but it does code for very important regulatory processes. We see more and more the amazing complexity of the human genome and testimony to the fact that we are “fearfully and wonderfully made!” (Psalm 139:14).