Doesn’t that require converging evolution? Is that even possible?
Hey, if your level of credulity is low enough, why not? ;’)
Lemurs and other prosimians have a working copy of IRGM, but new data show that junk DNA then rendered it nonfunctional in monkeys. Two mutations and the insertion of a retrovirus restored its function in apes and humans... Between 40 million and 50 million years ago, a slice of DNA called IRGM stopped functioning in the ancestors of modern-day monkeys. But 25 million years later, in the lineage that led to humans and great apes, three random events turned the gene back on... the precise role of IRGM in humans and apes remains unclear... In monkeys, the team discovered a piece of what could be "junk DNA" wedged in at the start of the gene... To make matters worse, the monkey gene sports a number of "stop codons," a type of genetic red light that prevents the production of any functional protein... But humans, apes, and monkeys share a common ancestor, so IRGM must have been resurrected somewhere along the line. As Eichler's group reports today in PLoS Genetics, the most plausible explanation--unlikely as it sounds--is that three random events brought the gene back to life.So, two strings of base pairs resemble one another, but have a number of differences the researchers have chosen to label "stop codons" instead of just sayin', we like to lay on our backs and find horseys and duckies in the clouds.