ScienceDaily: “Neutral Evolution Has Helped Shape Our Genome”
And speaking of genetic information, we note a new report in PLoS Genetics from Johns Hopkins researchers adds “to the growing mound of evidence that many of the genetic bits and pieces that drive evolutionary changes do not confer any advantages or disadvantages to humans or other animals,” reports ScienceDaily based on a Johns Hopkins Medical Institutions news release.
Johns Hopkins associate professor Nicholas Katsanis describes experiments that “demonstrate that one of the major architectural markers of the human genome, DNA repeat elements that make up over 40 percent of our genome, rose to prominence without offering any benefits to the organism it inhabits.” The team found more than 1,200 portions of mitochondrial DNA copied into chromosomes. These sequences, called numts, lack the “blueprint ... to make a protein that does anything” and are therefore neutral or “mildly negative” parts of the genome.
Based on molecular dating and the number of numts in chimps, mice, and rats, the team concluded that “most numts became embedded in our genome over a 10-million-year period centered roughly 54 million years ago[.]”
Creationists have, perhaps, two more satisfactory explanations of numts. Since the Fall (Genesis 3), our genome—and the genomes of all creation—have been subject to corruption and have steadily eroded, increasingly losing the vestiges of the original perfection. These genomic duplications are, in all likelihood, one example of the problems genomes now house, along with problematic mutations that have given rise to various malformities, diseases, and the like. Secondly, scientists continually uncover important functions in genetic segments once considered “junk,” “deserts,” and even “mildly negative” (for example, see News to Note, June 23, 2007, item #5, or More Than Meets the Eye: The Human Genome, item #2). Thus, although we cannot determine a function now, these repeated elements may facilitate some important function in an as-yet-unforeseen manner.
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