In 2003 the press widely reported suggestions by Alec Knight and Joanna Mountain of Stanford University that the original human language may have had clicks. The purported evidence for this is genetic: speakers of Juǀ'hoan and Hadza have the most divergent known mitochondrial DNA of any human populations, suggesting that they were the first, or at least among the first, surviving peoples to have split off the family tree. In other words, the three primary genetic divisions of humanity are the Hadza, the Juǀʼhoan and relatives, and everyone else. Because two of the three groups speak languages with clicks, perhaps their common ancestral language, which by implication is the ancestral language for all humankind, had clicks as well.