Final answer:
John Needham supported the theory of spontaneous generation with his experiments, which were later refuted by others like Spallanzani and Pasteur. Needham provided evidence in favor of spontaneous generation, but his findings were later challenged and refuted by Spallanzani.
Step-by-step explanation:
The scientist who provided evidence in favor of the concept of spontaneous generation is John Needham. Needham conducted experiments with broth, believing that microbes arose spontaneously from a "life force." His work was later challenged by other scientists, such as Lazzaro Spallanzani and Louis Pasteur, who showed that microbial life comes from existing life, not spontaneously from nonliving materials.
Pasteur's swan-neck flask experiment is particularly famous for definitively refuting the theory. Needham argued that microbes arise spontaneously in broth from a "life force."