|Image assembled from components at Clker clipart|
Repetitious "words" in DNA represent more than half of the human genome's three billion nucleotides.1 Because human reasoning essentially views the repetition of words in spoken languages as errors, these DNA sequences were first written off as meaningless junk. Secular scientists assumed that natural processes somehow produced the repeats over eons of evolution through accidental duplications and that these accidents were carried along in the genome as useless baggage. Now it appears nothing could be further from the truth since these repetitive words are linked with pervasive biochemical function.To read the rest, click on "Junk DNA…Trashed Again".
One class of repetitious human genome sequences recently highlighted in the news is called tandem repeats (TRs). These are simply stretches of DNA comprised of two or more contiguous copies of a "word" (called a motif) arranged in a head-to-tail pattern. For example, the TR "ttacttacttacttacgttac" is simply a repeat of the four-base motif "ttac" five times. Amazingly, these TRs are found all over the human genome: inside genes, outside genes, and even inside the protein-coding regions of genes. Among individual humans, many TRs vary in the length of the repeat. They have been used in forensics as highly effective DNA markers to solve criminal and paternity cases.