More Theoretical ComplexityNew research out of the University of Pennsylvania reveals yet another fascinating aspect of gene expression regulation. In the higher species genes are not one continuous DNA segment. Instead there are intervening segments within genes known as introns (intervening regions). Many introns are quite long and some are short. After a gene is copied by the transcription machinery (known as RNA polymerase), resulting in an mRNA transcript, these major and minor introns are spliced out of the mRNA by the major and minor spliceosomes, respectively. The new research shows that the minor spliceosomes can be turned off, thus turning off the expression of that gene.
When introns were first discovered, evolutionist figured they were yet more junk DNA. After all, why should genes have intervening regions which are simply removed from the gene copy? But introns are found throughout the genome. If they were junk why would they be so prevalent? Furthermore, how is it that spliceosomes can edit introns so precisely? If there were no introns then there would be no need for spliceosomes and so they would never evolve. And even if they did evolve there would be nothing for them to do and so evolution would discard them. On the other hand, if introns evolved first, then there would be no spliceosome to remove them. The resulting proteins would not function and the organism would quickly die. Either way, it is yet another conundrum for evolutionists.
In fact spliceosomes are incredibly complicated and perform sophisticated functions. The new research has found another function, and it presents yet another problem for evolution. The research discovered that the abundance of one of the key parts of the minor spliceosome can vary dramatically. Its abundance is controlled by a special protein and its abundance, in turn, controls whether the minor spliceosome is turned on or off. And this, in turn, controls whether or not a large number of very important genes are expressed.
Thus one single action has severe consequences for the cell. It is not a design that is gradually implemented. So not only are separate and independent structures and mechanisms simultaneously required for successful splicing, and not only are those structures and mechanisms incredibly complex, but the design space is highly nonlinear and discontinuous. This is yet another conundrum for evolution, the theory that calls for slow gradual change. Here is how one report described the findings:
The investigators found that a scarce, small RNA, called U6atac, controls the expression of hundreds of genes that have critical functions in cell growth, cell-cycle control, and global control of physiology. … These genes encode proteins that play essential roles in cell physiology such as several transcription regulators, ion channels, signaling proteins, and DNA damage-repair proteins. Their levels in cells are regulated by the activity of the splicing machinery, which acts as a valve to control essential regulators of cell growth and response to external stimuli. Dreyfuss, who studies RNA-binding proteins and their role in such diseases as spinal muscular atrophy and other motor neuron degenerative diseases, describes the findings as “completely unanticipated.”
The theory of evolution attempts to explain how the species arose. With the inexorable march of science, that explanation is becoming increasingly complex.