Plants have sensibilities, but are they conscious?
They experience reality differently than we do.
- The field of plant neurobiology studies the complex behavior of plants.
- Plants were found to have 15–20 senses, including many that humans have as well.
- Some argue that plants may have awareness and intelligence, while detractors persist.
Do plants have feelings? Not in a poetic, metaphorical sort of way but real feelings? Can they hate, love, or be bored? If you go around plucking flowers or mowing grass down with your lawnmower, are you causing these organisms pain? A rising field of plant neurobiology may answer these provocative questions.
This area of study was perhaps jolted into existence by the series of experiments carried out in 1966 by a former C.I.A. polygraph expert named Cleve Backster. He was, in turn, inspired by the work physicist Jagadish Chandra Bose, who found that playing different kinds of music near plants made them grow faster
Backster hooked up a galvanometer to a houseplant and found that the plant's varying electrical activity seemed to correspond to the thoughts from Backster and his colleagues. The experiment appeared to show that the plants reacted to whether the thoughts were positive or negative.
In one such trial, written up in the International Journal of Parapsychology in 1968, Backster's team connected plants to polygraph machines and found that a plant that saw someone stomping on another plant, essentially killing it, could pick out this "killer" out of a lineup. It registered a surge of electrical activity then this person appeared before it.
Cleve Backster using a lie detector on a household philodendron. 1969.
Credit: Gay Pauley
While Backster's findings were not duplicated by others, especially as he went on to find plants communicating telepathically, the area of study got a further boost in a 2006 paper published in Trends in Plant Science, where a team of biologists argued that the behavior you can see in a plant are not just a product of genetic and biochemical processes.
The authors, who included Eric D. Brenner, an American plant molecular biologist, Stefano Mancuso, an Italian plant physiologist, František Baluška, a Slovak cell biologist, and Elizabeth Van Volkenburgh, an American plant biologist, declared that a new field of plant neurobiology must be born to further understand plants. This area of biology research "aims to understand how plants process the information they obtain from their environment to develop, prosper and reproduce optimally," wrote the scientists.
They explained their observations that plants show behaviors that are coordinated by some type of "integrated signaling, communication and response system" within each plant. As profiled by Michael Pollan in the The New Yorker, these behaviors include responding to numerous environmental variables, such as light, temperature, water, microbes, and soil components like nutrients and toxins, and even gravity.
What's more, the plants utilize electrical signal and produce chemicals similar to neurons in animals, allowing them to respond to other plants. This led the authors to propose that plants exhibit intelligence, allowing them to react to their environment for both present and future actions.
In fact, studies showed that plants evolved to have between 15 and 20 separate senses including the human-like abilities to smell, taste, sight, touch and hear.
Does that mean plants, which compose 80 percent of the biomass on Earth, have complex nervous systems or even brains?
Maybe not brains like we understand them but intelligence. While brains are useful for problem solving and complex tasks, they are not the only way for organisms to interact with their environments. Humans tends to overestimate the relative greatness of their brains and faculties.
Stefano Mancuso, who was involved in the 2006 paper and runs the International Laboratory of Plant Neurobiology near Florence, Italy, contends that plants think, just differently, utilizing distributed intelligence. They gather information from their environments and respond in ways that are good for the whole organism. They also communicate, having 3,000 chemicals in their "chemical vocabulary".
Check out this TEDx talk with Stefano Mancuso
Many plant scientists over the years have pushed back against the field. One of its most ardent critics has been Lincoln Taiz, a now-retired professor of plant physiology at U.C. Santa Cruz. He believes that plant neurobiology ultimately leads down a slippery slope implying that plants can feel emotions like happiness or pain, can make decisions with purpose and perhaps even have consciousness. Chances of that being true are "effectively nil," writes Taiz in the recent paper "Plants Neither Possess nor Require Consciousness," published in the August 2019 issue of Trends in Plant Science.
While plants may exhibit sophisticated behaviors, their nervous systems are not comparable in complexity to those of animals and they have no similar brains, asserts the biologist. In fact, they have no need for consciousness, as it would require expending too much energy for their sun-oriented lifestyles.
He uses the case of a forest fire to point out the horror of what it would mean for plants to have sentience:
"It's unbearable to even consider the idea that plants would be sentient, conscious beings aware of the fact that they're being burned to ashes, watching their saplings die in front of them," writes Taiz.
Indeed, the idea of plants having self-awareness might seem too daunting and not yet supported by enough credible research, but the overall project of the field of plant neurobiology has already challenged the overly human-centric understanding of nature.
Dominique Crenn, the only female chef in America with three Michelin stars, joins Big Think Live this Thursday at 1pm ET.
Hungarian cartographer travels the world while mapping its treasures.
- Simple idea, stunning result: the world's watersheds in glorious colors.
- The maps are the work of Hungarian cartographer Robert Szucs.
- His job: to travel and map the world, one good cause at a time.
The world<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUyNS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzMzU3Njk1M30.rRdZpcl0bfVi4oBsljHdZSbcX0New9rdLcx6fr2mD7Y/img.png?width=980" id="f982a" class="rm-shortcode" data-rm-shortcode-id="fa67421340f881d5ab91463514cf9a6d" data-rm-shortcode-name="rebelmouse-image" />
Can you spot the world's ten largest drainage basins? In order of magnitude: Amazon, Congo, Nile, Mississippi, Ob, Parana, Yenisei, Lena, Niger, Amur. Image source: Grasshopper Geography
Africa<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUyNi9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzOTI2MzI0MX0.OeTS-scZwBES4AlZAan7fBlaBkznkig5hPjgcd1j6hw/img.png?width=980" id="e987c" class="rm-shortcode" data-rm-shortcode-id="2d3a8999ed4071a123b30efc5652fee9" data-rm-shortcode-name="rebelmouse-image" />
Africa is home to the rivers with the world's second- and third-largest catchment areas: the Congo (in blue), with a basin of 1.44 million square miles (3.73 million km2), and the Nile (in red), with basin area of 1.26 million square miles (3.25 million km2). The Nile is the longest river in Africa, though (4,130 miles; 6,650 km), followed by the Congo: 2,900 miles (4,700 km). The Congo River's alternative name, Zaire, comes from the Kikongo nzadi o nzere ('river swallowing rivers'). Image source: Grasshopper Geography
Europe<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUyOS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY0NTkzOTMyMH0.tq5fjnq8wvLqXY0C9gzfoUd0ahOAQ7IZQxbpVnC1FdY/img.png?width=980" id="a8ec4" class="rm-shortcode" data-rm-shortcode-id="1ce5f59691501103343e080905ce74a3" data-rm-shortcode-name="rebelmouse-image" />
The Volga (in yellow) is the river with the biggest catchment area in Europe (just under 545,000 square miles; 1.41 million km2). It flows exclusively through Russia, and the catchment area is entirely within Russia as well. Europe's number two is the Danube (in orange), which flows through 10 countries — more than any other river in the world. Its drainage basin (just over 307,000 square miles; almost 796,000 km2) includes nine more countries. Image: Grasshopper Geography
Germany<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUzMC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY0Mzk4ODA3Nn0.qX1sOfJWAI7TUbTQCiIob-R5p4_wj299wEtrYAUREmg/img.png?width=980" id="d5efa" class="rm-shortcode" data-rm-shortcode-id="8e73c53d75840f21b4f2ca4b8a1e7f51" data-rm-shortcode-name="rebelmouse-image" />
The hydrographic map of Germany is dominated by just four major drainage systems: the Danube (in orange) in the south, the Rhine (in blue) in the west, the Elbe (in purple) in the east and the Weser (in green) between the latter two. In Antiquity, the Rhine was the border between the Roman Empire and the Germans. Rome once attempted to shift the border to the Elbe, which would have radically altered the course of history, but it suffered a massive defeat in 9 CE at the Teutoburger Wald (roughly between both rivers). Image: Grasshopper Geography
Great Britain and Ireland<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUzMS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1OTk2MjM3MX0.nDy__OLIyC1arty4_2xd54fjTzmfsIZo-2pe5QRjjA4/img.png?width=980" id="31a6f" class="rm-shortcode" data-rm-shortcode-id="d089f66097f37a10ab854eaccdac3581" data-rm-shortcode-name="rebelmouse-image" />
Both Ireland and Great Britain are islands, as a result of which neither boasts a continental-class river. Twenty of the 30 longest British rivers are less than 100 miles (160 km) long. The longest river in Britain is the Severn (220 miles, 354 km), its catchment area shown in blue in the southwest. Ireland's longest river is the Shannon (224 miles, 360 km). Even combined they're not as long as France's Seine (483 miles, 777 km). Image: Grasshopper Geography
United States<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUzNC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY2MDYyMzEyM30.7S_83dA6bcLyID_7BhH1R_OTy61tpgDZrBMQ_iPwnjM/img.png?width=980" id="a879d" class="rm-shortcode" data-rm-shortcode-id="a7c74a7b5a7887fb2d13b40d5d96223c" data-rm-shortcode-name="rebelmouse-image" />
Spread-eagled across the central part of the United States, the Mississippi's drainage basin covers all or parts of 32 U.S. states (and two Canadian provinces). The easternmost point of Ol' Man River's catchment area is really far east: Cobb Hill in northern Pennsylvania. Here rises the Allegheny, tributary of the Ohio, which in turn flows into the Mississippi at Cairo, Illinois. Image: Grasshopper Geography
Washington State<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUzNS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY0MzU2MzM4OH0.mniqbkEQq84rNaWOQIl4fB4mOhNdJf5WactNyE_VsyM/img.png?width=980" id="adc4d" class="rm-shortcode" data-rm-shortcode-id="97eb5a5add49c06ef00ff0bca812b380" data-rm-shortcode-name="rebelmouse-image" />
Even leaving out the Mississippi, there's enough going on in the rest of North America to keep the eye occupied. Here's a drainage map of Washington State. The big fish in this much smaller pond is the Columbia River (drainage area in blue), the largest river in the Pacific Northwest. Only in the western third of the state is there a colourful counterpoint, in the multitude of smaller river basins that are draining into the Pacific or into Puget Sound. Image: Grasshopper Geography
Australia<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUzNi9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzOTM0ODM2NH0.U7vckwnoNoxf-bk8SuYO246hNMpR2zXILILsd4pas9o/img.png?width=980" id="38c2b" class="rm-shortcode" data-rm-shortcode-id="0c44d30d61c6cb94b8d5c7205cbabd58" data-rm-shortcode-name="rebelmouse-image" />
At 1,558 miles (2,508 km), the Murray is Australia's longest river. It is often considered in conjunction with the Darling (915 miles, 1,472 km), the country's third-longest river, which flows into the Murray. The Murray-Darling basin (in blue, in the southeast) covers just under 410,000 square miles (1.06 million km2), or 14 percent of Australia's total territory. Don't let that spidery network of river courses in the interior fool you: Australia is the world's driest inhabited continent (Antarctica, bizarrely, is drier). Image: Grasshopper Geography
Russia<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0MjUzNy9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYwNzg5MzIxOX0.WhShHLjjWdEh4FF_OZsY1oTN3Vc77X29TbMYbVHrHqA/img.png?width=980" id="f5cee" class="rm-shortcode" data-rm-shortcode-id="53acd93f1ab67be979e6ab128c144ce6" data-rm-shortcode-name="rebelmouse-image" />
Four of the world's largest drainage basins are in Russia: the Ob, Yenisei and Lena (origin of Vladimir I. Ulyanov's nom de guerre, Lenin) entirely and the Amur, shared with China. The Volga may be Europe's longest river, but 84 percent or Russia's surface water is east of the Urals, in Siberia. The sparsely-populated region is traversed by 40 rivers longer than 1,000 km. Combined, the Ob, Yenisey and Lena rivers cover a drainage area of about 8 million km2, discharging nearly 50,000 m3 of water per second in the Arctic. Image: Grasshopper Geography
Scientists have found evidence of hot springs near sites where ancient hominids settled, long before the control of fire.
Finances can be a stressor, regardless of tax bracket. Here are tips for making better money decisions.
- Whether you have a lot of money or a lot of debt, it matters how you handle your personal finances. A crucial step when it comes to saving is to reassess your relationship with money and to learn to adopt a broader, more logical point of view.
- In this video, social innovator and activist Vicki Robin, psychologist Daniel Kahneman, Harvard Business School professor Michael Norton, and author Bruce Feiler offer advice on achieving financial independence, learning to control your emotions, spending smarter, and teaching children about money.
- It all starts with education and understanding. The more you know about how money works, the better you will be at avoiding mistakes and the easier it will be to take control of your financial circumstances.