When she was working towards her Ph.D. in genetics at the University of California at Berkeley in the 1960s, my mother noticed something extraordinary: the organelles inside the cells she was studying looked surprisingly like single-celled free-living bacteria.
Was it possible, my mom asked herself, that bacterial cells somehow became integrated into other cells to form new organisms?
And could this be a driving mechanism of evolutionary change?
More established biologists laughed at her. Many of her colleagues dismissed her. A paper she wrote on the subject got rejected dozens of times. Later, Richard Dawkins, a famous British evolutionary biologist, called her “Attila the Hen.”…