Source Jerry Bergman
Study in Science News
The headline of a new article in Science News about the findings of a new study announced “A key to the mystery of fast-evolving genes was found in ‘junk DNA’”[i] The details show why some genes rapidly “become crucial because they regulate a type of DNA called heterochromatin. Once considered ‘junk DNA,’ heterochromatin actually performs many important jobs, including acting like a tightly guarded prison: It locks up ‘bad actor’ genes, preventing them from turning on and doing damage.” This new study indicates that what had been called “new genes,” supposedly created by random mutations and favored by natural selection evolution (such as the gene in fish that makes a novel antifreeze), were there all the time.[ii]
The genome is not only more complex than we thought a few years ago, it is more complex than we thought it could be. This study has opened the door a little wider to reveal that complexity. More research assuredly will open it even further.
Here are some of many examples of now ‘ex-junk’ DNA. Some portions contain docking sites where proteins can be attached to regulate genes. So far, more than 70,000 genes called promoters control nearby genes. More than 400,000 examples were found that function to enhance transcription, often influencing genes great distances away from the controlling element. Some non-coding regions affect how DNA is folded and packaged. Other ‘junk’ DNA is transcribed into RNA. Science writer Ed Yong comments, many evolutionists still “maintained that much of these sequences were, indeed, junk.” That had been true for the eight years prior to his article in 2012 about ENCODE. The deniers today, however, are dwindling in number.
This latest study reported on here will push a few more evolutionists to accept the design conclusion. The study supports the picture of a genome that is clearly well-designed, . In 2012, 80 percent of non-coding DNA was found to be transcribed, indicating it has a function. Evolutionists could claim that the remaining 20 percent is junk, allowing them to argue for evolution, however much less confidently. Even in 2012, Ed Yong felt that the remaining 20 percent was probably not junk either. That view is proving correct.
A review of a study from November 2019 remarks that it “should not surprise us that even in parts of the genome where we don’t obviously see a ‘functional code’” (speaking of the new type of code discovered) there are functions that are “not like anything we’ve previously considered.” They found portions responsible for “gene spaces” and “spatial compartments” such as genome 3-D shape design. Essentially, the non-coding DNA performs the role of punctuation and formatting of the coding DNA. This discovery is helping to resolve the “longstanding problems of “non‐coding DNA,” “junk DNA,” and “selfish DNA” leading to a new vision of the genome as shaped by DNA sequences.”
In other words, “junk” DNA, among other things, helps regulate the arrangement of information in the genome and the “structurally important elements in forming the correct shape and separation of condensed coding sequences in the genome.” Another finding was that non-coding DNA may have a role in “alternative splicing” – i.e., that a single sequence can “encode” more than one piece of information, depending on what is “reading” it and in which direction it reads it. For instance, “viral genomes are classic examples in which genes read in one direction to produce a given protein overlap with one or more genes read in the opposite direction.” Moore’s article relates another example:
the amino acid Threonine can be coded in eukaryotic DNA in no fewer than four ways: ACT, ACC, ACA or ACG. The third letter is variable and hence “available” for the coding of extra information. This is exactly what happens to produce the “genomic code”, in this case creating a bias for the AC and AC forms in warm-blooded organisms.
Moore is speaking of the fact that some amino acids can be coded by multiple codons. In the past, geneticists assumed that it did not matter which one, in this example of four codons for threonine, was used to make protein, but it is now realized that it matter, and this is one more example of why: the protein gets additional information from the type of codon specified. This is another example why mutations, even if they do not change the amino acid in a protein, are mostly deleterious.
Much more could be said about the findings of the study reviewed here, but these few examples will give the reader some insight into the direction research is taking us.