Does biology drive behavior? Yes, to some extent, argued science fiction author Octavia Butler in a 1996 interview. Sometimes a change in the brain, involving just a few cells, can change how you act, she said. Just look at the work of neurologist Oliver Sacks, or a disease that makes a wildebeest spend its last few days spinning in circles. But at the same time, we can work around our programming if we understand it. Both species in her Xenogenesis trilogy, humans and Oankali, have their in-built flaws, Butler added. [Biology In Science Fiction]