Which of the following is NOT a part of Darwin's theory of evolution by natural selection? a:More offspring are produced than can generally survive.
b:Individuals in a population vary in many ways.
c:Changes in an individual's genetic material are usually harmful.

Asample of digestive juice was removed from the stomach of a pig. the juice was placed in a test tube along with some grains of wheat. a second test tube was set up containing an equal number of wheat grains, with distilled water rather than digestive juice. the test tubes were kept for 8 hours at 40 degrees c. after 8 hours, the grains inside the digestive juice had broken into tiny particles. the grains of wheat, in the water, were wet but otherwise unchanged. what is the control group?