Here are two studies showing that mutations of the human and other organism genome are not random!
"... For the past century, an assumption central to Charles Darwin's evolutionary theory is that mutations are random and accidental and that natural selection favors such accidents. In an article published in the scientific peer-reviewed journal Genome Research, researchers have found the first evidence of non-random mutations in human genes. ...
Using a new and innovative method, the researchers ... have managed to prove that the rate of generation of the human hemoglobin S (HbS) mutation which protects one from malaria is higher in people from Africa in contrast to people from Europe. In other words, the mutation is not random but rather exists preferentially within the population of Africa where it is more needed."
Using a new and innovative method, the researchers ... have managed to prove that the rate of generation of the human hemoglobin S (HbS) mutation which protects one from malaria is higher in people from Africa in contrast to people from Europe. In other words, the mutation is not random but rather exists preferentially within the population of Africa where it is more needed."
"The work, published in Nature on January 12, finds that there’s a discrepancy in the rates of mutations among genes in model plant Arabidopsis thaliana. Specifically, genes playing a crucial role in survival and reproduction mutate far less often than those that are less important. ... On top of that, genes considered essential had a 37 percent lower mutation rate than those in which modifications would be less likely to prove disastrous. ...
[researchers] found evidence of specific epigenetic characteristics such as cytosine methylation that prevent mutations from occurring in those regions, not unlike protective barriers. These structures and the variability in mutation rates within a single organism’s genome ... suggest that “evolution created mechanisms that changed how evolution works.” ...
So the study’s authors calculated mutation bias among silent mutations, which don’t result in functional changes and still encode the same amino acid sequence as before when new proteins are synthesized. The effect, the paper shows, is still present among silent mutations as well as non-coding gene regions called introns, suggesting that the different mutation rates “is best explained by a genuine mutation difference” and not selection"
[researchers] found evidence of specific epigenetic characteristics such as cytosine methylation that prevent mutations from occurring in those regions, not unlike protective barriers. These structures and the variability in mutation rates within a single organism’s genome ... suggest that “evolution created mechanisms that changed how evolution works.” ...
So the study’s authors calculated mutation bias among silent mutations, which don’t result in functional changes and still encode the same amino acid sequence as before when new proteins are synthesized. The effect, the paper shows, is still present among silent mutations as well as non-coding gene regions called introns, suggesting that the different mutation rates “is best explained by a genuine mutation difference” and not selection"
Essential Genes Protected from Mutations (Long, comprehenisve article) Epigenetic structures appear to reduce the rate of changes in genes essential for survival and reproduction, a study finds, challenging the notion that mutations are evenly distributed throughout the genome prior to selection.
No comments:
Post a Comment