As described in the text, radiation and chemicals in the environment can induce mutations in cells. Why do the random mutations induced by the environment NOT violate or negate the results of the Lederberg's experiments

That would be a working theory.

Were is the question

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution