Comparisons of the genomes of humans and chimpanzees are revealing those rare stretches of DNA that are ours alone
By Katherine S Polalrd. research of Scientific American Study.
Six years ago She jumped at an opportunity to join the international team that was identifying the sequence of DNA bases, or “letters,” in the genome of the common chimpanzee (Pan troglodytes). She is a biostatistician with a long-standing interest in human origins, she was eager to line up the human DNA sequence next to that of our closest living relative the Chimpanzee , and take stock. A humbling truth emerged: our DNA blueprints are nearly 99 percent identical to theirs. That is, of the three billion letters that make up the human genome, only 15 million of them—less than 1 percent—have changed in the six million years or so since the human and chimp lineages diverged.
Evolutionary theory holds that the vast majority of these changes had little or no effect on our biology. But somewhere among those roughly 15 million bases lay the differences that made us human. She was determined to find them. Since then, she and others have made tantalizing progress in identifying a number of DNA sequences that set us apart from chimps.
My intake on this ; The researcher hit on a very interesting point. If the 118 base pair sequence that makes up have been so highly conserved over 300 million years , with only 2 base pair substitutions since chickens and chimps diverged, what type of natural selection process could account for 18 base pair changes in the span of 6 millions years ? Since we split with the chimps. And why haven’t we seen examples of 4, 6, 8 or more base pair variations in any other species?
Is it possible that the only viable genetic variation for the HAR1 sequence would be the ancestral and the human versions, with nothing in between? i THINK It is possible and correct so we as human and other animal are evolved differently and not from each other. The researcher did not talk or mention about the odds that random mutation could be responsible for 18 base pair changes all occurring at the same time in such a highly conserved piece of DNA code? As always they will say research under progress or it need farther study to get farther budget.
Thanks for reading, be kind and keep your mind open. Ask the question always and dont be blind by those who feed you what they call the truth.
Steve Ramsey. Calgary , Canada.
LOL.