1.It is not natural.
2.It can came up with side effects and unbalance some species.
Answer: The research of British naturalist Alfred Russel Wallace (1823-1913) played a pivotal role in developing the theory of natural selection. ... Wallace collected more than 100,000 insect, bird and animal specimens, which he gave to British museums. By 1855, Wallace had come to the conclusion that living things evolve.
Explanation:
Answer:
B. the variable that is changed and being tested
When you need to track changes over and short or long period of time
