Chapter 14, Problem 29A

Summary Introduction

To compare:

The contributions of Redi and Pasteur in disproving spontaneous generation.

Introduction: Evidence indicates that a sequence of chemical events preceded the origin of life on Earth and that life has evolved continuously over time. There are many theories which attempted to explain the origin of life. One of the oldest ideas about origin of life is spontaneous generation. It states that life arises from nonliving matter.

Answer to Problem 29A

Spontaneous generation was disproven by Redi and Pasteur. Redi tried to disprove the theory of spontaneous generation through his experiment on flies but failed to convince people about the origin of microorganisms. Then came the theory of biogenesis which was proved by Pasteur who through his experiment with sterile broth showed that only living organisms can produce other living organisms.

Hence, the theory of spontaneous generation was disproven by Redi and Pasteur.

Explanation of Solution

Rediinvestigated and tested the idea of spontaneous generation in 1668. He tested on flies and found that flies, not meat, produced other flies. He observed that maggots appeared only in flasks that were open to flies and closed flasks did not have any flies and maggots. He hypothesized that maggots and flies did not arise spontaneously from rotting meat. His results failed to convince everyone who believed that microorganisms may arise spontaneously.

Later, in mid 1800s, the idea of spontaneous generation was replaced by the theory of biogenesis. This theory was proved by Pasteur. It stated that only living organisms can produce other living organisms. He showed that biogenesis was true even for microorganisms. His experiment proved that sterile broth remained free of microorganisms until exposed to air.

Hence, the theory of spontaneous generation was disproven by Redi and Pasteur.