my grandmother was a chimpanzee

I'm not talking about my mother's mother.
   Like it or not, we are members of a large and particularly noisy family called the great apes. Our closest living relatives include chimpanzees, gorillas and orang-utans. The chimpanzees are the closest. Just 6 million years ago, a single female ape had two daughters. One became the ancestor of all chimpanzees, the other is our own grandmother !!
Source: Sapiens by Yuval Noah Harari

Image source pinterest

Or do you still believe in Adam & Eve?