The 1660s were an amazing time to be alive. Sure, the plague was going around and flushable toilets were few and far between, but the science was revolutionary! In fact, scientific work in this decade helped reshape the way we understand what it means to be alive.

Question

By the mid-1600s, many scientists had rejected the idea that animals like mice and eels come from nonliving, or inanimate, objects. However, it was still believed that smaller, simpler organisms were born through spontaneous generation.

For example, maggots were thought to be “born” directly from rotting meat. Before microscopes were invented, the bodies and behavior of small organisms were difficult to observe. Because scientists couldn’t see the reproductive processes of organisms like maggots and flies, spontaneous generation seemed like the only explanation for their origin.

In 1668, Italian scientist Francesco Redi decided to test this hypothesis. To do this, he put fresh meat in three jars. He left one jar open, covered one in gauze (a thin fabric with very small holes), and sealed the final jar.

After a few days, there were flies and maggots on the meat in the open jar. However, there were no flies or maggots on the meat in the gauze-covered and sealed jars. What’s more, flies appeared on the gauze before maggots did. Maggots didn’t come from raw meat, they came from flies!

Redi’s work was more than a gross collection of rotten meat and maggots (though it probably did smell pretty bad). With the results of his experiment, Redi was able to reject the theory of spontaneous generation, famously concluding that “All life comes from life.”
How did the results of Redi's experiment disprove the theory of spontaneous generation? answer this question as if you're a 7th grader just doing your science brainpop

Answer 1

Francesco Redi's experiment was super important because it helped prove that small organisms, like maggots, don't just appear out of nowhere from things like rotting meat. Before his experiment, people thought that things like maggots could just magically "pop" into existence from the meat all by themselves, which was called spontaneous generation.

In his experiment, Redi used three jars with fresh meat: one jar was left open, one was covered with gauze, and the last one was tightly sealed. In the open jar, flies could get to the meat, and after a few days, he saw flies and maggots on it. But in the gauze-covered jar, no flies or maggots showed up, and the same thing happened with the sealed jar.

This showed that the maggots weren’t coming from the meat at all! Instead, they were coming from the flies laying eggs on the meat. Flies could land on the gauze but couldn’t get through to lay their eggs in the sealed jar. So, since flies are living things that already existed, Redi concluded that life comes from other life, not just from random stuff like rotting meat.

In a nutshell, Redi proved that maggots come from flies, which were already alive, rather than being born from the meat itself. That helped kick out the idea of spontaneous generation and showed that all life comes from other living things!