Lacking the brain and nervous system needed to conjure consciousness (not to mention nociceptors, the animalian cells that react to painful stimuli), our vegetal cousins endure munching insects and withering drought without a hint of suffering as we know it.
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That said, plants — like every form of life — have evolved tools to avoid and mitigate damage to themselves. Over the past few decades, biologists have learned much about their astonishing ability to sense and react to danger in their environments.
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In 2014, researchers at the University of Missouri found that plants can “hear” the vibrations of caterpillars feeding on their leaves, and elicit chemical defenses in response. In 2019, another group of researchers, from Tel Aviv University, found that certain plants emit ultrasonic sounds when stressed.
Plants simply don’t need consciousness, nor pain. While disagreeable sensations taught our ancestors to avoid imminent threat — to withdraw their hands from the fire, so to speak — plants developed their own, unconscious strategies. Besides, bodily injury isn’t a grave concern for an organism that can regenerate at will. “When tissues are damaged in a plant,” [researcher Elizabeth] Van Volkenburgh says, “it’s not as dire a situation as in an animal.”