Large scale function for ‘endogenous retroviruses’
by Shaun Doyle
Photo <www.stockxpert.com>
Endogenous retroviruses (ERVs) are some of the most cited evidences for evolution.
They are part of the suite of ‘junk DNA’ that supposedly comprised the
vast majority of our DNA. ERVs are said to be parasitic retroviral DNA sequences
that infected our genome long ago and have stayed there ever since. These short
DNA strands are found throughout the human genome, and make up about 5% of the DNA,1 or about 10% of the total
amount of DNA that is classified as transposable elements (i.e. 50%).2
However, the term ‘endogenous retrovirus’ is a bit of a misnomer. There
are numerous instances where small transposable elements thought to be endogenous
retroviruses have been found to have functions, which invalidates the ‘random
retrovirus insertion’ claim. For instance, studies of embryo development in
mice suggest that transposable elements (of which ERVs are a subset) control embryo
development. Transposable elements seem to be involved in controlling the sequence
and level of gene expression during development, by moving to/from the sites of
gene control.3
Moreover, researchers have recently identified an important function for a large
proportion of the human genome that has been labelled as ERVs. They act as promoters,
starting transcription at alternative starting points, which enables different RNA
transcripts to be formed from the same DNA sequence.
‘We report the existence of 51,197 ERV-derived promoter sequences that initiate
transcription within the human genome, including 1,743 cases where transcription
is initiated from ERV sequences that are located in gene proximal promoter or 5’
untranslated regions (UTRs).’4
And,
‘Our analysis revealed that retroviral sequences in the human genome encode
tens-of-thousands of active promoters; transcribed ERV sequences correspond to 1.16%
of the human genome sequence and PET tags that capture transcripts initiated from
ERVs cover 22.4% of the genome.’5
Moreover, researchers have recently identified an important function for a large
proportion of the human genome that has been labelled as ERVs.
So we’re not just talking about a small scale phenomenon. These ERVs aid transcription
in over one fifth of the human genome! ‘These data illustrate the
potential of retroviral sequences to regulate human transcription on a large scale
consistent with a substantial effect of ERVs on the function and evolution of the
human genome.’3 This again debunks the idea that 98% of the human
genome is junk, and it makes the inserted evolutionary spin look like a tacked-on
nod to the evolutionary establishment. These results support the conclusions of
the ENCODE project, which found that at least 93% of DNA was transcribed into RNA.
Evolutionists have used shared mistakes in ‘junk DNA’ as ‘proof’
that humans and chimps have a common ancestor. However, if the similar sequences
are functional, which they are progressively proving to be, their argument evaporates.
It seems that evolutionist Dr John Mattick, director of the Institute for Molecular
Bioscience at the University of Queensland, Brisbane, Australia, was spot on in
his assessment of the gravity of the ‘junk DNA’ error:
‘The failure to recognize the full implications of this—particularly
the possibility that the intervening noncoding sequences may be transmitting parallel
information … may well go down as one of the biggest mistakes in the history
of molecular biology.’6
Both biblical creationists7
and ID proponents8 predicted
that transposable elements, such as ‘endogenous retroviruses’, would
have a function. In 2000, creationist molecular biologist Linda Walkup proposed
that God could have created transposable elements to facilitate variation (adaptation)
within biblical kinds.7
If the ‘junk DNA’ is not junk, then it puts a big spanner in the work
of molecular taxonomists, who assumed that ‘junk DNA’ was free to mutate
at random, unconstrained by the requirements of functionality. As Williams points
out:
‘The molecular taxonomists, who have been drawing up evolutionary histories
(“phylogenies”) for nearly every kind of life, are going to have to
undo all their years of “junk DNA”-based historical reconstructions
and wait for the full implications to emerge before they try again.’9
Related articles
Further reading
Related resources
References
- Conley, A.B., Piriyapongsa, J. and Jordan, I.K., Retroviral
promoters in the human genome, Bioinformatics 24(14):1563–1567,
2008. Return to text.
- Thornburg, B.G., Gotea V. and Makałowski W., Transposable
elements as a significant source of transcription regulating signals, Gene
365:104–110, 2006. Return to text.
- Batten, D., No joy for junkies, Journal of Creation
(TJ) 19(1):3, 2006; <creation.com/junkies>.
Return to text.
- Conley et al., ref 1, p. 1563.
Return to text.
- Conley et al., ref 1, p. 1566.
Return to text.
- Mattick, J., cited in: Gibbs, W.W., The unseen
genome: gems among the junk, Scientific American 289(5):26–33,
November 2003; pp. 29–30. Return to text.
- Walkup, L., ‘Junk’ DNA: evolutionary discards
or God’s tools?, Journal of Creation (Technical Journal)
14(2):18–30, 2000; <creation.com/dnajunk>. Return to text.
- Luskin, C., ‘Large Scale’ function for endogenous
retroviruses: Intelligent Design prediction fulfilled while another Darwinist argument
bites the dust, Discovery Institute, 21 August 2008, <www.evolutionnews.org/2008/08/function_for_endogenous_retrov.html>,
accessed 12 September 2008. Return to text.
- Williams, A., Astonishing DNA complexity demolishes neo-Darwinism,
Journal of Creation 21(3):111–118, 2007; p. 113.
Return to text.
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