The book on the Netlab project often returns to the notion that learning is merely a form of adaptation and that, conversely, adaptation is merely a form of long-term learning. This, in turn, all fits under the umbrella notion that
memory is behavior.
The idea that learning is adaptation is learning is forwarded as a possibility, mainly as a better means of discussing the concepts. This (in my opinion) provides a clearer and more converged understanding of how memory works in biological organisms. This could be very wrong, of course, so it's important to describe it properly. That way it, and not a straw man, can be critiqued. This article represents one such attempt to properly describe it. . .
Batesian mimicry is when a non-noxious/non-poisonous plant or animal projects the appearance of a poisonous plant or animal, allowing it to avoid being eaten by predators.
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Those predators, goes the logic, which have partaken of the poisonous organism and survived, would have become very sick, and would have learned to avoid ingesting anything that appears to be that organism in the future. This will include those organisms who are not poisonous, but merely look, or act, like the poisonous organism.
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Can an organism learn from one instance of ingesting something that makes it sick? This is one of the first questions that is likely to occur to somebody who is interested in brains and behavior. This is a very exciting possibility, from a purely behaviorist point of view, for a number of reasons.
First, we must assume that the effects of the poison will not always immediately make themselves known to the ingesting predator organism. This means the predator must make an association between its bad feelings and the act of ingesting the food, even though there may be a very long delay period between the action and the consequence. Are such delay periods possible in, for example, small insectivores?
A single incident must also be fully impressed into long-term memory after a single lesson. This would have seemed a lot less likely a couple of decades ago, but these days, with studies behind us that show a strong correlation between stress and retention, it is a little easier to stomach (sorry). It is still interesting in that it produces (presumably) life-long retention of the incident, in a single experience. In this regard it also might help move the understanding of stress-retention forward.
Perhaps the learning occurs at a different
temporal frame of reference than those we normally associate with neurons. Another possibility that has been posited to explain the survival advantage imparted to Batesian prey organisms is that their predators don't learn as individuals. Instead, they adapt as a group via generational selection. In this case, the group can be viewed as the organism, and each individual within the group becomes a rough analog of a single adaptive cell. That is, the individual is to the group organism, what a neuron/synapse is to the individual.
Combinatorial variation, both chaotic and (possibly) random, will produce a small number of individuals within the predators who have an otherwise unexplainable aversion, or fear, of the image projected by the poisonous prey. The predators who are born with such a defect are the lucky ones. Here, those individuals who are not born with some randomly imparted aversion to the appearance projected by the poisonous prey animal will eat it and die.
An all-or-nothing mechanism, such as death, is only one possibility. They don't have to actually die from the poison. In an intensely competitive environment, an organism that merely becomes sick and unable to feed and defend itself for a few days will likely not be able to fully recover from the ordeal. Its chances of reproduction, even if it only becomes sick for a few days, will be greatly reduced.
The predator animals who have a randomly imparted phobia towards the appearance projected by the poisonous prey will avoid it. They will be more productive, and, over time, individuals with the inherent phobic behavior will thrive. Their once-unexplainable behavior will become the normal behavior of their species.
On the other side of the ledger, the poisonous prey animals will be protected and be permitted to thrive, but more importantly in this discussion, individuals within other species that just happen to look similar to the poisonous species will enjoy the same protection from being eaten by the phobic race. In this case, non-poisonous individuals who most closely resemble the poisonous species will thrive over their brothers and sisters who don't, and will become the dominant component of their species.
Temporality is one distinguishing characteristic of learning and memory. Different temporal spans of learning seem to be supported by different underlying mechanisms. Normally, one thinks of these different mechanisms for bringing about different learning time-frames at the level of an individual neuron or synapse. These may include differences in how proteins are activated at the membranes and synaptic clefts of neurons, for example. But memory, learning, and differences in temporality are distinguished by many different underlying mechanisms, some of which are not necessarily neuronal.
Here I've used Betesian mimicry as an analog to demonstrate that the learning system can be an entire species. Note that a species is beyond simply viewing a population of organisms as a corporate organism. It extends to a sort of type.
- Mimicry In Nature
- Other Examples of Adaptation==Learning (not based on mimicry)
- Background
more soon...
-djr
Stand Out Publishing
