The idea that plants can make conscious decisions is controversial, but a new study on climbing French beans suggests that the concept may be starting to take root.
What was the experiment?
Researchers based at the Minimal Intelligence Lab at the University of Murcia, Spain, and the Rotman Institute of Philosophy in London, Canada, placed 20 potted plants in the center of cylindrical huts. The plants were alone or accompanied by a garden reed planted 30 centimeters further into the ground.
The scientists then used photography to track the passage of time to track the movements of the plants until the tip of the shoots made contact with the sticks. They found that the shoots would grow on more predictable paths in the presence of the canes, almost as if they could sense it in their environment and adjust their growth patterns as a response.
Does it show conscious intention?
Some plants respond to their environment by, for example, curling up their leaves when touched, or enveloping and digesting their prey in their leaves. The basic mechanisms of these answers have been well studied, but the more philosophical questions, such as whether the plants ‘intelligently choose’ to perform such actions, are a very recent idea.
The Rotman Institute of Philosophy, Dr. Vicente Raja, one of the authors of the study, does not say that the experiment proves once and for all that plants can act with conscious intention, but it does show that the beans in the experiment did . more than simply responding to external stimuli.
“It’s one thing to respond to a stimulus, like light. It’s another thing to observe an object,” he says. “If the movement of plants is controlled and influenced by objects in their environment, then we are talking about more complex behaviors, not reactions, and we should be able to identify similar cognitive signatures to those we observe in humans and some animals. . “
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Where can plant awareness arise?
Plant neurobiology was officially established in 2006 as a research area. Its proponents draw parallels between the pathways of electrical signal found in plants and the nervous system found in animals, to argue that plants can act purposefully.
Plants use electrical signals in two ways. First, to regulate the distribution of charged particles (ions) across their various membranes. The leaf of a plant can curl, for example, because a movement of ions causes the transport of water from its cells, causing it to change shape.
Second, to transmit long-distance messages from one part of the plant to another. An insect bite on one leaf, for example, can cause defensive reactions in leaves in the distance. Both actions can occur as if a plant decides to respond to a stimulus.
Only in the last decade, when we connect animals with feelings, does it take time to respond to them. If we separate our prejudices and do not think that some characteristics belong only to us, we can move the field forward much faster, ‘says dr. Paco Calvo, director of the Minimal Intelligence Lab at the University of Murcia and co-author of the study. .
“I’m glad to be refuted, but we need to be open to possibilities.”
What do the critics say?
Some researchers argue that these responses are merely genetically coded and that, thanks to countless generations of natural selection, they are the occurrence of deliberate actions.
In a paper entitled ‘Plants Own and Require No Consciousness’, published in 2019, Prof Lincoln Taiz, a botanist at the University of California, Santa Cruz, rejected the idea of plants with characteristics such as consciousness and cognition on that basis. that they do not possess the necessary structural, organizational and functional complexity that the animal brain had to develop before its consciousness could emerge.
“The biggest danger of anthropomorphic plants in research is that they undermine the objectivity of the researcher,” says Taiz.
‘What we have seen is that plants and animals have developed different life strategies. The brain is a very expensive organ and there is absolutely no benefit for the plant to have a strongly developed nervous system. ‘
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