Ask to ant!

Some time ago, an enlightening communication with a friend make me think whether or not we understand a scientific question. The conversation, as habitually, starts in a non-conventional tom about the relationship between ants and plants. The affair is something like this:

a. The plant offer to ant food and a good place to nest, directly or not (in this case, the nest is into the plant);
b. In return, the ants protect the nest and, consequently, the plant.

My friend, as a good naturalist, dedicated some time observing the behavior from these ants and their relationship with the host plant. He noted that those ants performed the act of prune the plant which gave him shelter. A strange behavior, given that decreases the photosynthetic area of the leaves and impairs the plant. Could that behavior decrease the fitness of the plant?

We feel inclination to throw the question “Why is that ant doing this?”, “What motivation behind the behavior?” My friend has some very reasonable hypothesis in order to explain the event. However, before test it, he want to test the force of his question. Would be the suitable ask? Would be a properly formulated question? The answer to two questions is a categorical “No.” Nature makes no plans and have no aims. Thus, talk about a motif behind of any behavior only makes any sense if we are talking about entities able to rationalize (i. e., makes complex decisions based in previous judgment).

You could think that an ant or even simplest organisms like a fungus are able to response in a “programmed” manner to stimulus and it would be makes decision. If a fungus releases spores (a stress form resistance) when submitted to treatment with stress agents it had to experiment an event and makes decision about how act. It’s a simple algorithm to imagine. You receive an input data and must return some answer. Independently of emitted answer, it was product of a decision, conscientious or not.

But this kind of capability to makes decision could be called of rationalizing? The answer once again is “No.” Let’s exercise our imagination: Suppose you design a simple robot on a field with pillars. Each pillar has a color, blue or red. Your robot is equipped with a color sensor and is able to decide if will turn to left or right depending on color of the pillar toward him. If the pillar is blue, then he turns to right. If red, then turns to left. The algorithm cover makes decision, but would you say that the robot made a judgment? In objective terms the answer is – Yes, he did? The robot needed judge if the pillar was red or blue in order to make decision.

Of course you noticed the fact that we design our robot with an algorithm and tools that allow his distinguish between two colors. That decision’s algorithm is so simple that seems impossible that robot fail in judgment of what pillar is blue or red. Unfortunately, maybe, in nature the algorithm is not always so efficient. Errors of judgment are frequents. We, humans, are also embedded with tools that allow us to distinguish between colors or any other feature.

This tools that enable us to make decision also makes us commit errors frequently and daltonism is an example of this glitch with our genetic algorithm. Thus, is evident that a judgment don’t need is always right to produce a decision.

We know that our designed robot is able to make decision based on judgment, as well as an ant or a fungus, but only the last two can make decision based on errors of judgment. Anyway, if you are tuned at the read, you noticed that I consider the act of rationalize as a capability of make a complex decision. I order to explain, we can back to that interaction between ants and plants. To admit that the ant realize an action to achieve a specific aim, we need to suppose some like the following order of things:

1. That the ant receives a chemical clue from plant;
2. That the chemical clue makes her prune leaves;
3. That the ant perceives some benefit to itself or colony at the act of prune leaves;
4. That the ant makes a judgment about the benefit and resolve perpetuate the action of prune.

This order of things is compatible with a rationalizing process and involves a complex decision. We’re able to make complex decision based in judgment and, hence, makes sense to say that some of our action have a definite purpose, even if they are hidden. It’s more or less like the affair described by Steven Weinberg:

E M. Forster’s novel Where Angels Fear to Tread gives a good example of teleology making the difference between description and explanation. Philip is trying to find out why his friend Caroline helped to bring about a marriage between Philip’s sister and a young Italian man of whom Philip’s family disapproves. After Caroline reports all the conversations she had with Philip’s sister, Philip says, “What you have given me is a description, not an explanation”. Everyone knows what Philip means by this – in asking for an explanation, he wants to learn Caroline’s purposes (Weinberg, 2002).

This is the sense of purpose that I think makes no sense in the nature, unless we’re talking about being like Philip, a typical Homo sapiens containing well developed cognitive abilities.

Naturally, there’s a situation that involves the capacity of detect rationalization in beings of another species. You should ask to ants about him purpose (in terms of final cause) when they doing a determined action. I confess have no certainty about cognitive abilities of ants or plants. However, I suspect that the behavior integrates a complex repertory, which is product of genetic mixture under epigenetic control of thousand years and no from a deliberate action.

Would the ant decided prune leaves in order to gain some benefit or would that behavior part of a complex repertory and non-intentional that ensure the survival of colony? We can demonstrate experimentally whether or not there’s correlation between 1. The prune action, and 2. The increase of fitness. With auxiliary experiments and some controls is still possible observe if that correlation imply causality. However, there’s no experiment able to demonstrate that the ant decided make the action of prune with intention of increase the fitness of nest plant. If something can not be tested, clearly can not be object for science. What no mean that never can be, but meanwhile, it interest only to philosophy. Richard Dawkins was victim of wrong usage of term “purpose” when talking about what he called extended phenotype in end chapter of his book “Selfish gene.

It is not entirely clear what its Darwinian purpose is, but it must have one, for the beavers expend so much time and energy to build it. The lake that it creates probably serves to protect the beavers from predators… (Dawkins in The Selfish Gene).

Both books “The extended phenotype” and “The Selfish Gene” were hardly criticized due to contain error or conceptual confusion, like that generated by the term “Darwinian purpose.”

It’s a strong inference about the beavers’ behavior and the same to ants. What if the prune behavior by ants correlates with an increase in fitness of plant? Could we conclude that plant intentionally produce a chemical signal which induced the ant to increase plant fitness? Or that ant intentionally prunes the plant for the same reason? I think that both answers is No. The plant, maybe, produces some chemical signal. However, it’s not intentional but an event that revealed itself as benefit to plant along the time.

Such as Dawkins, lacks in many researchers the philosophical reads necessaries to distinguish between scientific and philosophical questions. The philosophy allows us investigate questions like “Why?” while science concern more with questions like “How?” We must be responsible when talking about science. The empirical science, that which demand test, is not able to answer questions of kind “Why?”. This, indubitable, withdraw many of magic of science and exposes her limits. At the same time, it is what allow us learn about objective reality and understand mechanisms or process that occurs in nature. The purpose by what those mechanisms occurs are a job for our imagination. How my friend noted, while analyzed the force of his question “what the motif?”, the nature actually have no motivations.


Steve Davis. The Extended Phenotype – How Richard Dawkins Got It Wrong Twice. In Science 2.0, February 16th, 2009, 01:44 AM.
Richard Dawkins. O gene egoísta. Companhia das Letras. 1976.
Karl Popper. A lógica da pesquisa científica. Cultrix, 1958.
Steven Weinberg. Can science explain everything? anything? Caltech. 2002.

Acknowledges: To Paulo Sergio Mendes Pacheco Junior and João Henrique Campos for their critical reading.

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This work by Alison Felipe Alencar Chaves is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.


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