Day 67

Day 67

Can plants remember?

Animal biologist Monica Gagliano made a claim that was so controversial that her paper was rejected by 10 scientific journals before it was finally published. Her research and experiments led to the conclusion that plants, like us, have memory.

She tested her theory with a Mimosa plant, which closes its leaves when disturbed. She found a way to drop the plant without harming it. As expected, the Mimosa closed its leaves each time it was dropped.

"After five or six drops, the plants would stop responding, as if they'd learned to tune out the stimulus as irrelevent," Pollan says. "This is a very important part of learning — to learn what you can safely ignore in your environment."

To test whether the plant was just getting worn out from all the dropping, Gagliano shook them instead.

"They would continue to collapse," Pollan says. "They had made the distinction that (dropping)was a signal they could safely ignore. And what was more incredible is that (Gagliano) would retest them every week for four weeks and, for a month, they continued to remember their lesson."

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