Similarities between human and plants (Part-03: Smell similarity)

Functional similarities between human and plant (P.C.: Research Gate)

Human and plant consciousness share a remarkable number of similarities, particularly in relation to the five senses which both use to navigate the complexities of the world. There has been an ever-increasing body of research developing over the years demonstrating that consciousness is indeed not limited only to animals and humans, but plants as well and more so even objects we consider inanimate like rocks and metals. After all, there is no difference in composition between any of these things at the subatomic level. Everything we can perceive and even that which we cannot are made of electrons and protons circling around a nucleus. At the sub-atomic level there is little difference between the human brain and dirt (not to diminish the incredible complexity of the brain…). 

Smell Similarity

The parasitic vine called dodder is the sniffer dog of the vegetable world. It contains almost no chlorophyll – the pigment that most plants use to make food – so to eat it must suck the sugary sap from other plants. Dodder uses olfaction to hunt down its quarry. It can distinguish potential victims from their smell, homing in on its favorites and also using scents emitted by unhealthy specimens to avoid them (Science, vol 313, p 1964).

Dodder is exceptionally sensitive to odors, but all plants have a sense of smell. In animals, sensors in the nose recognize and bind with molecules in the air. Plants also have receptors that respond to volatile chemicals. What do they smell?

Back in the 1920s, researchers with the US Department of Agriculture demonstrated that treating unripe fruit with ethylene gas would induce it to ripen. Since then, it has become apparent that all ripening fruits emit ethylene in copious amounts, can smell it, and respond by ripening. This ensures not only that a fruit ripens uniformly but also that neighboring ones ripen together, producing more ethylene and leading to a ripening cascade. Coordinated ripening is important because it attracts animals to eat the fruit and disperse the seeds. Ethylene is a plant hormone that regulates many processes, so being able to smell it has other advantages too, such as in the coordination of leaf-color changes in the autumn.

Above all, however, smell allows plants to communicate. Research in the 1980s showed that healthy trees in the vicinity of caterpillar-infested ones were resistant to the pests because their leaves contained chemicals that made them unpalatable. Other trees isolated from the infestation did not produce these chemicals, so it seemed that the attacked trees had sent an airborne pheromonal message that primed healthy trees to prepare for imminent attack. We now know that many volatile chemicals are involved.

Acknowledgment: Helix, Quora, Zazenlife.com

Similarities between human and plants (Part-02: Touch similarity)

Functional similarities between human and plant (P.C.: Research Gate)

Human and plant consciousness share a remarkable number of similarities, particularly in relation to the five senses which both use to navigate the complexities of the world. There has been an ever-increasing body of research developing over the years demonstrating that consciousness is indeed not limited only to animals and humans, but plants as well and more so even objects we consider inanimate like rocks and metals. After all, there is no difference in composition between any of these things at the subatomic level. Everything we can perceive and even that which we cannot are made of electrons and protons circling around a nucleus. At the sub-atomic level there is little difference between the human brain and dirt (not to diminish the incredible complexity of the brain…). 

Touch Similarities

Plants live in a very tactile world. Branches sway in the wind, insects crawl across leaves, and vines search out supports to hang on to. Plants are even sensitive to hot and cold, allowing them to respond to the weather by doing things like changing their growth rates and modulating their use of water. Simply touching or shaking a plant is often enough to reduce its growth, which is why vegetation in windswept locations tends to be stunted.

All plants can sense mechanical forces to some degree, but tactile sensitivity is most obvious in the carnivorous Venus flytrap. When a fly, beetle or even a small frog crawls across its specially adapted leaves, these spring together with surprising force, sandwiching the unsuspecting prey and blocking its escape. The Venus flytrap (pictured) knows when to shut because it feels its prey touching large hairs on the two lobes of the trap. But it won’t just snap shut with any stimulation – at least two hair touches must occur within about 20 seconds of each other. This helps to ensure that the prey is the ideal size and will not be able to wiggle out of the trap once it closes.

The mechanism by which the Venus flytrap feels its prey is uncannily similar to the way you feel a fly crawling on your arm. Touch receptors in your skin sense the insect and activate an electrical current that passes along nerves until it reaches your brain, which registers the fly’s presence and instigates a response. Likewise, when a fly rubs up against the Venus flytrap’s hairs, it induces a current that radiates throughout the leaves. This activates ion channels in the cell membrane and the trap springs shut, all in less than one-tenth of a second.

Although most plants do not react this fast, they feel a mechanical stimulus in the same way. What’s really fascinating is that even at the level of individual cells, plants and animals use similar proteins to feel things. These mechanoreceptors are embedded in the cell membranes and, when stimulated by mechanical pressure or distortion, they allow charged ions to cross the membrane. This creates a difference in electrical charge between the inside and the outside of the cell, which generates a current. Unlike us, plants lack a brain to translate these signals into sensations with emotional connotations. Nevertheless, their sensitivity to touch allows them to respond to their changing environments in specific and appropriate ways.

Acknowledgment: Helix, Quora, Zazenlife.com

Plant hormones (auxin, gibberellin, cytokinin, ethylene and abscisic acid) activity illustrated simply (Video length: 2:52 minutes)

Video: Plant hormones activity (V.C.: Neural Academy)

Photo: Plant hormones (Fuseschool)