Being a natural history filmmaking student, I’ve seen a few nature documentaries in my time. But one that really stretched my imagination was the BBC’s ‘The Private Life of Plants’. David Attenborough’s voice rolls over and we’re immediately transported to a place of wonder… ‘[Plants] face many of the same problems that animals face throughout their lives if they’re to survive. They have to fight one another, compete for mates, and invade new territories. But the reason we’re seldom aware of these dramas is that plants of course live on a different time scale’. I remember being amazed at the behaviours of these plants when showed using a time lapse – lunging aggressively at one another in a dramatic war for light in the depths of the rainforest, and chasing the direction of the sun on the alpine plains. They were, indeed, alive. However, the zoologist in me ‘knew’ that plants lacked a nervous system, and the vegan in me was reluctant to think that they could feel pain. And so we have our next vegan myth to debunk – can plants feel pain?
Intelligence without brains
Plants are undeniably alive, though not in ways that are immediately recognizable to us. They feed – but not on other living things. They breathe and circulate nutrients that keep them alive – though they don’t have organs. They reproduce and grow – though they barely touch each other. They sense things like light, water and animals, and their movements are to their own time schedule. They are highly capable of surviving despite their lack of a brain.
It is hard for us to imagine how something without a brain can feel anything. Our brains are there to tell us what to do, make decisions, and remember things we might need for later. If I’m going to the supermarket I need to remember to get soft tofu so I can make some cookies. Or, if I’m having dinner at a restaurant I need to remember what undercooked chicken tastes like so I don’t get food poisoning. The memories our brains hold help us to quickly respond to things that threaten us by preparing our bodies to run or fight. Ever had a bad experience with something and felt a cold chill wash over you when you encountered it again?
But plants move much more slowly than animals. Do they need an organ that gives them quick reactions in the same ways our brains do then? Perhaps not, and research has found that plants can actually remember things without needing a brain. Have you ever seen those plants that curl their leaves up when you touch them? It’s a response that helps them to tuck away their delicious leaves so that insects that touch them can’t reach them.
Anyway, when researches took these plants, called the shy plant, and dropped them to the floor, they curled away their leaves when they felt the ground. After a few of these drops from the same height however, the leaves remained open. The plant had remembered that nothing bad happened to it when it touched the floor and it was safe to remain open.What’s even more amazing is that the plant ‘remembered’ this for a few weeks afterwards.
There’s a reason it’s called nervous
If plants don’t need a brain to remember things, can they feel pain in the absence of one too? The nervous system is what makes us feel pain – it is a network of nerve cells distributed all throughout the body that are also connected to the muscles, organs, and the brain. It is responsible for other things too, like making our muscles work when we want to run away, and stopping our digestion so we don’t throw up while we do so.
The brain makes the decisions when it receives a message, like pain, from the nerves, and sends another message to the rest of the body with instructions on what to do to keep your body safe. If it makes you feel cool, think of your brain as the Godfather, and your nerves as his mobster relatives carrying out the deeds for the family’s safety.
Without a brain, and without a nervous system, it seems plants wouldn’t be able to feel pain. But as we’ve seen with memory, not all the functions of the brain necessarily need a brain to work. Researchers in Plant Neurobiology, a budding (if you’ll excuse the pun) new field of science, are reluctant to say that plants feel pain at this point. Additionally, as pain is defined as a ‘distressing feeling’ and plants are too slow moving to have use for simple emotions like distress, it is unlikely they can feel pain.
The Vegan’s Dilemma?
Though my love for plants has increased 10 fold by reading about their capacity for memory and other amazing feats (like sharing nutrients with other plants through roots systems and producing toxins that scare away animals that begin to eat them), I don’t think I’ll be waking up to the sound of kale screaming in my head. For one thing, it takes around 13.5 kilograms of fodder to produce 450 grams of beef – meaning more plants are being killed to feed meat-eaters than vegans. For another, two wrongs don’t make a right – that is, if we cause plants pain, it doesn’t justify causing animals pain.
If you’d like to know more about some of the amazing things plants can do, check out the website for plant neurobiology here.
Peace and science,
Images by Summer Gleeson.