I know and that is the question. Why there is only one unbroken linfe of female descendants and not 2, 5 or say 50 today? For example say 50% of the world's population come from Mitochondrial Eve, 20% from a Mitochondrial Doris 30% from a Mitochondrial Samantha. Why is there only one, single surviving line of female descendants and not at least one more? It is logical that some matrilinal lines are more widespread then the others, it's just
how could one maternal line evolutionarily totally "defeat" all other lines and become the only one available?