The interest of the study on the intelligence of plants can be primary, that is, interest in the subject itself. However, in the context of the study of the origin and evolution of life on Earth, the study of the intelligence of plants acquires a specific relevance. In fact, if we consider the hypothesis that all animal cells come from a common ancestor and that this cell-ancestor-animal must come from a cell-predecessor-plant, the study of the intelligence of plants leads us to think that animal intelligence must have its origin in plant intelligence.

Currently, there are laboratories of plant neurobiology and the amount of publications on the subject are constantly increasing. However, there is still a large field of research on the intelligence of plants.

In this post on Veterinaria Digital we will focus first on the definition and then on the anatomophysiological basis that encourages intelligent answers.

In a general sense, intelligence is defined as "the faculty of the mind that allows learning, understanding, reasoning, forming an idea of reality and making decisions". This definition is not applicable to plants, since it implies the existence of a mind and plants have no mind, in the sense of a well-defined organ, anatomically.

KNOW HOW TO CHOOSE
For this reason, we prefer to start from the etymology of the word intelligence. Derived from the Latin "interligere" is a word composed of the terms "intus" (between) and "legere" (choose). So, intelligence can be defined as the ability to "know how to choose" between different alternatives to solve a problem. This is a definition that can be used in the study of the intelligence of plants, since it is defined as a capacity in itself and not as the faculty of an organ.

This approach allows us to see plants, and by extension of plants, not as an inert part of the landscape, but as a collective of living beings that analyze the environment and make decisions in order to defend their individual survival and its collective expansion.

ANIMAL INTELLIGENCE
The relationship relating to plants intelligence with animal intelligence is appropriate to expose the following explanation. It is known that primitive animal cells are dependent on primitive plant cells. In essence, the needs of oxygen, carbohydrates as a source of energy and derivatives of shikimic acid, as modulators of the metagenetic expression of animal genetic code, are three subjects of dependence of animals on plants.

Analyzing this dependence, we can reach de conclusion (this is our working hypothesis) that the primitive cells were prokaryotes of vegetable character capable of obtaining their food from solar or chemical energy sources. Animal cells, although they may have their own origin, are quite likely to appear as plant cells that have lost the ability to produce oxygen, carbohydrates and shikimic acid derivatives, but have maintained the ability to use it. It is a simple option, in our opinion, more likely than the opposite option, which would consist of: the appearance of cells of an animal nature, with a genetic code adapted to the use of plant-based resources.

ANIMAL INTELLIGENCE BASES
If we apply this hypothesis to the subject of intelligence, we can admit that the bases of animal intelligence must be in vegetable intelligence.

This will be the focus of the dissemination of scientific information in www.veterinariadigital.com, in the subjects related to the intelligence of the plants: to look for in them the anatomophysiological bases of the animal intelligence. And as every anatomical and physiological basis has a genetic origin: search, by this way, a point of genetic union between the vegetable and the animal.

To summarise: we will explore, as  a topic for future posts, some related topics that have previously been exposed in this Popular Science blog of Veterinaria Digital.
It is a first group of responses to external stimuli:
(1) Response to external stimuli in a straight line: phototropism, geotropism, tigmotropism, hydrotropism that direct parts of the plant towards the stimulus.
(2) Response to external stimuli in variable directions called nastias: Epinastia (curving down), photonastia (closing or opening of flowers, according to light intensity), hyponastia (curving up), nictinastia (opening or closing as circadian cycles), chemistry (reaction to chemical substances), seismonastia (reaction to mechanical shocks) and thermonasty (reaction to temperature)

A second group of physical structures and active substances, which can be the physiological basis of the answers described above:
(3) Existence of stratoliths (mineral formations) existing in the rhizoids of the algae and in the root tips with sensory functions to the gravity
(4) Existence of membrane proteins as foreign exchange detectors
(5) Accumulation of auxins, actins and myosin in root cells that give cells motility

On the basis of this information we will advance in the search for the origins of primitive animal intelligence in primitive plant intelligence.

You can read more information on this topic:
Intelligence of the plants. Dissemination 93
The intelligence of vegetables-2: The movements of plants. Dissemination 94
Intelligence of the plants. Dissemination 114