Scientists have long believed that mitochondrial DNA segments are not exchanged. This supposed stability has also been fundamental in many evolutionary studies. It seems, however, that this conviction is wrong and can question, for example, many discoveries about evolution.
Until now it was thought that the DNA of the mitochondria was received only by the mother, without mixing it with that of her father. Consequently, the researchers considered that the only changes were spontaneous mutations. As one can foresee its rhythm of occurrence, the time interval between two who used the existing differences between an ancient man and a modern man was the one that determined when the divergences occurred.
However, a few years ago it was discovered that a man had received this type of DNA from his father. They have now conducted more studies and found evidence of cross-segment exchange. They still do not know how or at what speed this process occurs.