Question

Fruit flies display geotaxis, or a response to the earth's gravity. If the flies are within a vial and the vial is flipped upside down, the flies will crawl to the top of the vial. A researcher notices that a group of flies that had been exposed to radiation no longer exhibit geotaxis. How could you provide further evidence that this behavior is innate and not learned?

Answer 1

As in all experiments one must use the scientific method... One of the conditions during experimentation is the use of a control for the subject. You should have several fruitflies exposed to radiation while other not (this would be your control)

Answer 2

If you hatch fruit flies so that you are studying them from the beginning stages of life, and they still exhibit geotaxis then you know it is not learned because they will do it from the moment they emerge as flies.