The distinct groups operate, to some level at least, under genetic control and are not mere environmental adaptations.
"It has opened the door to genetic control of the med fly."
Family history is very important, and the response to diet is probably under genetic control.
But scientists are generally more cautious when discussing genetic controls.
Recent advances in genetics have made it possible to study the genetic control of flowering.
However, it remains likely that a genetic control for sootiness does exist.
He decided on a career examining genetic control of vertebrate development.
Other proposed factors include genetic control of sexual orientation.
The genetic controls for the depth of shade are not presently understood.
And even the question of handedness is tricky: it seems to be not entirely under genetic control.