10 Ways Plants are More Like Animals Than You Think
By Toptenz, 17 December 2015.
By Toptenz, 17 December 2015.
Recently, scientists have found evidence that a lot of the plants all around us behave more like creatures rather than inanimate objects. Once considered to be at the bottom of the food chain, plants are slowly rising to the status of a legitimate living thing. Just like animals, they have genuine characteristics that imply a real life experience. Plants can feel, see, smell, and even cry out in pain. This perspective is gaining ground in the scientific community to the point where the Swiss government has granted, for the first time ever, plant rights alongside human and animal ones. Plants may be lower form of animals and here are ten reasons to believe it.
10. They Can “See”
Seeing the world doesn’t necessarily require having a pair of eyeballs. Plants have developed the ability to see light waves through the use special light receptors evolved over thousands of years. These light receptors tune into different wavelengths to help discern, among other things, the sun’s location in the sky. Two types of receptors prevail in plant species: phytochromes and phototropins. Both are situated just beneath a plant’s cell membranes. Phytochromes are sensitive to far red light of the spectrum, which allows plants to know when the sun is setting. Phototropins are sensitive to the blue spectrum of light, which allows plants to find the sweet spot to maximize photosynthesis during the day.
This visual acuity may not be as fine-tuned as ours, but plants aren’t mobile like us. They don’t need it. Plants can survive by seeing light waves to know where to direct their leaves or when to shut down at night. What may appear like blindness to us is a really full spectrum to our friendly neighborhood leafy greens. Plants can see, just like other animals do.
9. They Can Smell
When it comes to smell, plants can take a whiff when they really need to. In fact, their sense of smell isn’t that different from ours. Smell involves capturing the release of volatile chemicals into the air through nostrils or other means. Scientists have confirmed that our brainless plant-friends can indeed process these volatile chemicals without a pair of nostrils. This sense can even help them discern the difference between friend and foe. For example, the dodder plant seedling is a parasitic plant that can’t engage in photosynthesis on its own. So, it looks for other plants in which to suck the food energy from. But how does it choose a suitable host? It smells. Dodder plants picks up volatile chemicals emitted from potential hosts to determine which one is stronger and healthier breed over others.
In one experiment, a dodder plant preferred a tomato plant over a wheat one - by scent alone. Another example of smelling? Fruits will synchronize their ripening process based on which one has ripened the most. The ripened sends out volatile chemicals in the air that is picked up by less ripened plant and, as a result, ripen together at roughly the same rate. Plants can pick up volatile chemicals in the air just like us. These scents help them navigate the wild and pick their friends. It’s a far cry from a human nose, but plants definitely have some kind of keen ability to smell just like animals do.
8. They Can Hear
They say that big ears are a sign of wisdom. If that’s true, then some of the oldest plant species alive shouldn’t be judged by their covers. Plants teach us that they can hear without a pair of ears. Scientists now believe that plants pick up sound through specialized proteins called mechanoreceptors found within the cell membranes that respond to air pressure. Sound waves cause their leaves to vibrate ever so slightly, thereby disrupting these proteins that send a signal back to the rest of the plant. Proof of this ability comes with studies conducted on mustard plants. Researchers from the University of Missouri have discovered that mustard plants can actually hear the chomping sound of caterpillars munching on their leaves.
To prove it, scientists took sound recordings of the chomping sounds as well as other sounds such as insect mating or wind blowing through air. They played back the recordings to find the plant would responded to the chomping sounds only. The plants recognized the sound and responded to it in the same way it would in the wild. This response proved that plants can hear just like humans. And in case you’re wondering if plants prefer Mozart over Beethoven: researchers found that a simple pulse tone is healthier for plants than complex tones such as classical music.
7. They Have Feelings
Plants, like animals, have feelings too. They are among the most sensitive creatures you’ll meet. Being immobile, they live their lives in quiet desperation as they are subjected to the elements and predators of the wild. Like the rest of us, they can’t just pick up and run either. Did you know that the scent from freshly cut grass signals “cries of pain” from a plant recovering from its cuts and bruises? Researchers from the University of Bonn in Germany learned that gases were released after plants got cut or injured its leaves or stem.
These gases weren’t visible to the human eye, so laser-powered microphones were used to pick up the most sensitive waves produced by the release of gas. The Swiss government went as far as to pass legislation to protect plants from unnecessary pain and suffering by extending the rights to dignity and freedom to plants like any other animal. Although many think the legislation is a joke, rest assured that the Swiss government (much to the chagrin of some scientists) really do believe that plants feel pain when they are injured. A penalty is levied to any researcher who breaks the code.
6. They Can “Talk”
Plants can be quite the chatter bugs. They may not vocalize sounds like most animals, but they can send out signals to fellow plants when it’s necessary for their survival. Although it may not be as elegant as a Shakespearean soliloquy (maybe better, in fact), researchers have confirmed that plants do indeed “talk” to each other. This process isn’t any different than other animals in the wild that send sound waves when crying out for help or warning fellow species of danger. For example, when a maple tree is attacked by bugs, it releases a pheromone into the air picked up by its neighboring maples so that they can better develop a defense strategy to repel the attack.
In some cases, plants don’t just send out signals to other plants of the same species, sometimes they send out cries for help to insects too. When insects such as caterpillars start munching on their leaves, it is common for some to send out volatile chemicals to larger predatory insects (like dragonflies) to take care of business for them. Plants can talk. They scream when they’re in trouble or alert loved ones to protect themselves. They’re just like any other animal surviving the wild ion Planet Earth.
5. They Have Memories
Be careful what you say to your plants, because they just may remember it for a long time. Researcher Monica Gagliano worked with a plant species called Mimosa Pudica, a plant which looks a lot like a fern. When disturbed, the Mimosa temporarily collapses its leaves on itself. Gagliano dropped the Mimosa plant every five to six seconds, thereby causing it to collapse its leaves in reflex. Over time, she realized that the Mimosa stopped collapsing its leaves altogether. It tuned out the plant stopped collapsing its leaves when it learnt that the repeated disturbance didn’t cause any harm whatsoever.
To confirm this hypothesis, Gagliano shook the plant instead. The leaves collapsed again. Gagliano then dropped it one more time, but again, nothing. She dropped it again a week and month later. Still, the Mimosa remembered that the dropping would cause it no harm and therefore didn’t bother collapsing its leaves. This behavior is similar to what we would expect from an animal in the wild who learned, through memory, which stimuli was dangerous and which could be ignored.
4. They Have a Sense of Family
Plants are family-oriented. If they could operate a camera, Facebook would be littered with photos of their family members basking in the sun and killing malicious insects on their leaves. Granted, it might not be so easy to map out its family tree, but scientists believe that plants who live in close proximity tend to be a part of the same “family.” For example, the Yellow Jewelweed is a plant species with its kin close by. This plant species grows quickly to out-compete other plants for sunlight. It will even out-compete below ground by extending its root system past other plants. But the Jewelweed has been observed to hold back on its ambitious when in the same vicinity of its own kin.
A Jewelweed simply won’t compete with its own kind. If it recognizes another Jewelweed, it will deliberately re-allocate its growth to avoid stealing sunlight from family. Higher stems or deeper roots will be preferable to larger leaves that might inadvertently starve another Jewelweed from much needed sunlight. Researchers have observed this behavior in other plants too. They also believe that plants recognize kin through their complex root systems.
3. They Care About Their Communities
Plants don’t just take care of family. If the plant shares the same species, it is not unlike one plant to help out others as long as their next of kin are taken care of first, of course. Take, for instance, acacia trees. These trees will help its own kind when grazed upon by wild animals looking for a meal. The tree being eaten will be the first to produce tannin to defend itself from grazing animals as well as send an airborne scent to other acacia trees to do the same. It’s a way of acacia trees taking care of one another in the wild. It’s an act of altruism for other members of its species who share the same life experience and desire to protect themselves from similar predators.
Maple trees do the same. When attacked, they send out a warning to other maple trees, who in effect, alter their chemistry to deal with the oncoming predators. Plants stick together. They know it’s a hard life so, for them, helping each other out is a must-have in the wilderness.
2. They Can Defend Themselves in the Wild
Plants might seem pretty to some, but others know them to be among the most vicious creatures in the wild. It’s hard to take notice of their attacks since they tend to stay rooted in the ground. But plants can fight back. For example, when mustard plants hear caterpillars chomping on their leaves, they purposely created insecticide-like chemical compounds to ward them off.
When female cabbage butterflies lay their eggs on a Brussels sprout plant with tiny portions of glue, the plant will detect the glue and swiftly change its chemistry in order to beckon female parasitic wasps to counter the butterflies’ measure. For each self-defensive measure, plants use sight, smell, touch and sound to know when they are under attack and how to act decisively just like any other animal in the wild. Plants, like their fellow animals, care about being alive.
1. They Have a “Brain” and Human-Like Genes
Zombies won’t be munching on plant-matter any time soon. It’s not a species that one would expect to have a brain. But scientists are discovering that the lack of grey matter may not necessarily mean that plants don’t have some kind of way to pull off cell communication as well as cell information storage and processing. The root-brain hypothesis suggested that the tip of the root, the meristem of a plant, acted like the plant’s brain like it does in lower animals. Other functions regarding cells seem to be regulated by genes quite similar to those found even in human DNA.
For example, Dr. Daniel Chamovitz from the Manna Center for Plant Biosciences at Tel Aviv University discovered a group of genes plants use to measure light or darkness. The same gene were found in human beings too and, in both organisms, served to regulate their circadian rhythm. Plants even produce neurotransmitters such as dopamine and serotonin just like humans. The reality: plants are brainy creatures in their own right, so don’t count them out so quickly. After all, you’ll want to be on their good side when they rise up and become the dominant species, as M. Night Shyamalan predicted.
Top image: Acacia trees in the Serengeti, Tanzania. Credit: Charles J Sharp/Wikimedia Commons.
[Source: Toptenz. Edited. Top image added.]