As we know, each of us has half of our mother’s DNA and half of our father’s DNA. But these two halves have never been predictable. The process of reshuffling genes, “crossing over” is random, as are mutations. However, there is an interesting study by some scientists from deCODE genetics, in Iceland, published in the online edition of Nature. By studying the mixing map on a shorter scale (that of the grandparents), in an analysis lasting twenty-five years, they managed to identify those areas of the genome less subject to mixing, so to speak “protected areas”.
Bear in mind that DNA mixing is the basis of evolution, which has been going on for hundreds of millions of years for each species through random mutations that are sometimes advantageous and sometimes disadvantageous. The advantageous ones tend to move forward, of course, organisms with disadvantageous mutations become extinct (by natural selection). This study also took into consideration women, in which different areas of DNA were found to have less recombination, not cross-over, and examining new mutations that occur in children.
An interesting thing concerns the observation that women have fewer crossovers, but recombinations increase with age (and this explains why having children late in life is more risky for chromosomal alternations in the child), a change that is not observed in men. Feminists might get angry (sex is a bit sexist), but regardless of this huge study we already knew that men remain fertile until old age while women do not.
In any case, having identified the areas of the genome where DNA undergoes more recombination (even in children) and where it is more stable (inherited from parents) opens up new medical frontiers. A small step for our individual genes (we keep the ones we have now), a big step for the genetics of humanity to come.