by Elysse Baumbach, 5/28/16
Repetitious “words” in DNA represent
more than half of the human genome’s three billion nucleotides.1Because
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.1
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 amotif) 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.
Despite knowing about these TR
sequences and using them as reliable genetic markers, scientists have known
very little about their actual function. Historically, anomalies like these
repeating sequences, that seem to make little sense upon first glance, were
often relegated to the trash bin of “junk DNA.”
However, one group of researchers
recently took a different approach and hypothesized that these sequences may
have a purpose. They developed a set of experiments to test the effect of TRs
on gene expression and the epigenetic modification of DNA. Epigenetic modification is the
addition of molecular tags to the DNA molecule without changing the actual DNA
sequence. The result is altered gene expression.
http://creationrevolution.com/junk-dna-trashed-again/
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