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Evolutionists have thought of junk DNA as useless DNA leftover from past evolutionary
permutations. According to the selfish or parasitic DNA theory, this DNA persists only
because of its ability to replicate itself, or perhaps because it has randomly mutated into
a form advantageous to the cell. The types of junk DNA include introns, pseudogenes,
and mobile or repetitive DNAs. Recently, many of the DNA sequences, formerly consigned
to the junk pile, have begun to obtain new respect for their role in genome structure and
function, gene regulation and rapid speciation. On the other hand, there are examples of
what seem to be true junk DNAs, the sequences that had lost their functions, either to
mutational inactivation that could have occurred post-Fall, or by God-ordained time limits
set on their functions (Walkup, 2000). To identify legitimate junk DNA, and to try to
decipher the genetic clues of how genomes function now and in the past, specified
criteria are presented. The rapid, catastrophic changes on the earth caused by the flood
may also have been mirrored in genomes, since each species had to adapt to post-flood
conditions. A new creationist theory may explain how this rapid diversification came
about by the changes caused by repetitive and mobile DNA sequences. The so-called
‘junk’ DNAs that have perplexed creationists and evolutionary scientists alike may be the
very elements that can explain the mechanisms by which God is at work in His creation
now and in the past (Walkup, 2000). The last decade of the 20th century has seen an explosion in research into the structure and function of the DNA in genomes of a wide
range of organisms. As of April 2000, the whole genomes or full DNA complements of
over 600 organisms have been sequenced or mapped (NCBI). Researchers in this vanguard
are continuously expanding their frontiers.
Researchers in the new field of genomics—the comparison of the structures, functions
and hypothetical evolutionary relationships of the world’s life forms—are working furiously
to deal with the huge inflow of data. Now more than ever, scientists can see at the most
basic level the similarities and differences of organisms and are seeking to understand
how the blueprints of cells are decoded and regulated. A major goal of genomic studies is
to understand the role, if any, of the various classes of the so-called junk DNA. Junk or
selfish DNA is believed to be largely parasitic in nature, persisting in the genomes of
higher organisms as ‘evolutionary remnants’ by their ability to reproduce and spread
themselves, or perhaps because they have supposedly mutated into a function the cell can
use (Walkup, 2000).
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