As we use the Y Chromosome to trace the fatherline, you may be wondering why we do not use the X Chromosome to trace the motherline. Yes, the X Chromosome in a male comes from his mother, but in a female, they get an X Chromosome from each of their parents, and it is a 50% chance which X Chromosome they pass on to their child. This would not, therefore trace the motherline’s ancestral origins, as parts of the X Chromosome may have come from your mother’s father, and even if not, certainly some parts of will have come from another male ancestor somewhere down the line. The X chromosome DNA is also shuffled each generation and so we cannot easily trace which ancestor the DNA came from, and cannot build a tree relating different types.
Mitochondrial DNA is passed from a mother to all of her children, but only daughters then pass it on. Like the Y Chromosome, mitochondrial DNA is also inherited as one block and contains many markers that allow us to identify over one hundred different groups of related lineages and many subtypes within each group. mitochondrial DNA is very interesting, as women often left their places of birth to find partners. Your mitochondrial DNA may have originated on the other side of the world.