Why are we all descendants of Africans?

No, it’s just a hypothesis

The problem is this. This year, biomolecular scientists have discovered that mitochondrial DNA inherited from mothers does not mutate from generation to generation, and Some genetic markers of the Y chromosome remain stable without mutating as they are passed from father to son. Therefore, even after many generations, tracking the Y chromosome and mitochondrial DNA can allow scientists to trace back to their paternal and maternal ancestors long ago. Therefore, in the mid-1980s, American geneticist Wilson compared the mitochondrial DNA of 148 women from around the world based on this theory and found that African women had twice as many genetic markers as women from other places. This means that modern people must have lived in Africa twice as long as they have lived in other places. Through calculations, Wilson and others found a unique "grandmother" for modern people, who lived in the 20s The African woman 10,000 years ago is the famous "mitochondrial Eve". Eve was not the only woman at that time, but her descendants began to leave Africa 130,000 years ago and brought her mitochondrial DNA to the world. In the same way, we also find We have such a "Y chromosome Adam". The relevant theories are not easy to explain here. (I am so tired of typing) You can refer to the March 2007 issue of "Chinese Geography" for other related books