Indeed, while it may have initially seemed to evolutionists that introns were inserted into genes during the course of evolution, findings of introns at conserved insertion sites, in various species, tell evolutionists that some of the introns are ancient, and were present in the earliest eukaryotes. But this suggests that the super complex editing machinery that splices the introns is also ancient. This is yet another example of early complexity whereas evolution predicts simple beginnings.
One virtue of this ancient origin view is that introns could be cast as evolutionary enablers in the origin of proteins narrative. After all, the expressed regions (exons) between the introns tended to conveniently be protein domains which can be rearranged and shuffled to modify the protein. As one of today’s leading textbooks explains, “It is believed that the organization of DNA coding sequences as a series of such exons separated by long introns has greatly facilitated the evolution of new proteins.” Or as one paper put it, by the 1980s “it had become a textbook dogma that introns were retained from a primordial RNA world in order to speed evolution by exon shuffling.”
It is yet another example of the tremendous serendipity in the evolution genre as evolution creates itself. Evolution creates everything from genes, chromosomes and alleles, to horizontal gene transfer, epigenetics, and now introns, so that, yes, evolution can occur. And evolutionists never think twice about the unlikely story they have contrived.
But the ancient origin view cannot explain many introns which don’t fit the pattern. Evolutionists view those as of more recent origin. In fact, evolutionists have constructed a battery of explanatory devices in their attempt to fit the data to their theory.
Perhaps introns are mostly ancient and exons arose within them, providing new genes. Or perhaps introns were mostly introduced later, during the course of evolution, interrupting the genes. And perhaps many introns were lost in the course of evolution, or perhaps introns slide around. And maybe introns served as sponges to reduce the deleterious impact of mutation showers.
As usual the genre elaborates from a rich set of devices and mechanisms, and it is often difficult to parse the empirical data from the theoretical constructs. Consider these passages from a recent paper which demonstrate how deeply immersed evolutionists are in their theory and how far they have departed from empiricism:
The fact that the alternative splicing products were of the cassette type (i.e., exons that are alternatively included/skipped from the mature transcript) did not question the emerging conceptualization of introns as definite DNA segments. Yet seeking to identify mechanisms for the rapid evolution of protein-coding sequences, records were cited of so-called cryptic donor/acceptor splice sites, and speculations were advanced that splicing-altering mutations could cause extensions/contractions of exons at intron junctions.
Interest in intron sliding models diminished on the belief that intron sliding could not be a frequent phenomenon. Under the notion of introns as fixed genomic segments, intron sliding is perceived as uncommon because it calls for the simultaneous occurrence of two mutations. Other paths, by a series of two or more short-range extension/contraction events of intron–exon boundaries, were deemed likely to be deleterious at the protein level. Such events would be feasible when the aberrant mRNAs contained premature stop codons that could be targeted by nonsense mediated decay.
Evolutionists think nothing of extreme speculation that amounts to little more than story-telling. And now, new intron research is adding more confusion to the narrative.
The intron patterns are now forcing evolutionists to switch from their view that intron insertions are random events. Sound familiar?
Evolutionists view biology as a fluke, and like the Epicureans and their veering atoms, evolutionists believe unguided events just happened to create the most complex structures known. Everything from mutations to genome insertion events occur at the roll of a die.
This is the evolutionary view even though so often it is falsified by reality. For everything from mutations to, yes introns, show patterns. And when these patterns cannot be fitted into the common descent model, then evolutionists must admit that the events do not occur at random.
Introns are yet another example of how evolution is less of a revealing explanation than merely a tautology. Whatever we find in nature, evolution will explain it no matter how strained is the narrative.