Neurobiology and Behaviour
Instinct - Behaviour that is not dependent on learning.
All animals function - to some degree - on FAP's. From the tiniest slug, to the largest elephant, to the brainiest human; we all are inherently inclined to perform certain behaviors. It's simply hard-wired into our brains.
A fixed-action pattern is an instinctive behavioral response to certain stimuli that all members of a species produce similarly to each other. Examples include:
· mating rituals of certain animals, including birds.
· migration of certain animals, including salmon
· some species of moths that instantly drop to the ground if they sense a bat
· the dance of a honeybee to show members of the hive where food is located
Fixed action patterns are different than reflexes because even though animals are born with both, fixed-action patterns are more complex. Fixed-action patterns can be relevant to a single gender of the species, for example in mating dances, when females and males may demonstrate different behaviour. But all the females will act in the same way as each other, and all the males will act in the same way as each other.
The higher order of animal, the fewer instinctive behaviours occur, and more of what the creature knows is based on learning. Humans have no instinctive behaviour complicated enough to count as a fixed-action pattern.
When we look at FAP's we need to ask:
· Function — How does the behaviour affect the animal's chances of survival and reproduction? Why does the animal respond that way instead of some other way?
· Causation — What are the stimuli that elicit the response, and how has it been modified by recent learning?
Videos:
Stickleback:
http://www.youtube.com/watch?v=ZfcGZCGdGVE
Bird feeding young:
http://www.youtube.com/watch?v=htbsQc1UZ6c
Geese :
http://www.youtube.com/watch?v=vUNZv-ByPkU&feature=related
Honey bee:
http://www.youtube.com/watch?v=-7ijI-g4jHg&feature=related
Fooling a wasp:
http://www.youtube.com/watch?v=EXLigFEri98&feature=related
The Dutch ethologist Niko Tinbergen, Nobel Prize, was one of the first to study FAP in vertebrates, such as seagulls, ducks and so on.
A classical example of FAP studied by Tinbergen is the goose behavior of picking eggs up. When the female notices an egg outside the nest (key stimulus) , it begins a repeated movement to drag the egg with its beak and neck. However if the egg slides off or if it is removed by the researcher, the goose continues to repeat the stereotypic movements even if the egg is absent, until it reaches the nest, when then it does it all over again. Therefore, FAP seems to correspond to a fixed neural circuitry elicited by the overall trigger stimuli.
Human beings also display various instictive movements, which generally manifest themselves soon after birth. They are called behavioral reflexes. One example is the characteristic prehensive reflex of the hand of new-borns, who firmly hold any object.
Quantitative measures showed that infants apply more strength if they touch hair. This FAP appeared by evolution among primates, so that the infant can hold to the mother's hair and do not fall off when she moves briskly. Given a rope, new-borns hold firmly and remain suspended by themselves.
Male Sticklebacks
Male sticklebacks are fish that are characterized by their red bellies. Their fixed action pattern is in response to the red bellies of other fish. When they observe another fish with a red belly, they will attack it. This is how they protect their territories from other male sticklebacks.
Niko Tinbergen tested this fixed action pattern by exposing male sticklebacks to models that did not necessarily look like fish, but had red undersides. The male sticklebacks attacked every model with the red, but ignored the lifelike model with no red underside.
What's going on here and why?
How are FAP's affected by Natural selection
Black cap
Fruit flies
Cichlids
Great tits
However, a behaviour only made of fixed action patterns would be particularly rigid and inefficient, reducing the probability of survival and reproduction, so the learning process has great importance, as does the ability to change the individual's responses based on its experience. It can be said[by whom?] that the more the brain is complex and the life of the individual long, the more its behaviour is "intelligent" (in the sense of being guided by experience rather than stereotyped FAPs).
[edit] Animal Training
Understanding ethology, or animal behaviourism, is very important in animal training. Considering the natural behaviours of certain animals or specific breeds of animals enables the trainer to select the breed best suited to perform the required task. It also enables the trainer to encourage the re-performance of certain naturally-occurring behaviours, and also the discontinuance of undesirable behaviours. [11]
Learning
Learning occurs in many ways, one of the most elementary being habituation.[12] This process consists of ignoring persistent or useless stimuli. An example of learning by habituation is the one observed in squirrels: When one of them feels threatened, the others hear its signal and go to the nearest refuge. However, if the signal comes from an individual that has caused many false alarms, the other squirrels ignore the signal.
Another common way of learning is by association, where a stimulus is, based on the experience, linked to another one that may not have anything to do with the first one. The first studies of associative learning were made by Russian physiologist Ivan Pavlov.[13] An example of associative behaviour is observed when a common goldfish goes close to the water surface whenever a human is going to feed it, or the excitement of a dog whenever it sees a collar as a prelude for a walk.
[edit] Imprinting
Main article: Imprinting (psychology)
Example of imprinting in a moose
Being able to discriminate the members of one's own species is also of fundamental importance for reproductive success. Such discrimination can be based on a number of factors. However, this important type of learning only takes place in a very limited period of time. This kind of learning is called imprinting,[14] and was a second important finding of Lorenz. Lorenz observed that the young of birds such as geese and chickens followed their mothers spontaneously from almost the first day after they were hatched, and he discovered that this response could be imitated by an arbitrary stimulus if the eggs were incubated artificially and the stimulus were presented during a critical period that continued for a few days after hatching.
[edit] Imitation
Imitation is often an important type of learning. A well-documented example of imitative learning occurred in a group of macaques on Hachijojima Island, Japan. The macaques lived in the inland forest until the 1960s, when a group of researchers started giving them potatoes on the beach: soon, they started venturing onto the beach, picking the potatoes from the sand, and cleaning and eating them.[15] About one year later, an individual was observed bringing a potato to the sea, putting it into the water with one hand, and cleaning it with the other. Her behaviour was soon imitated by the individuals living in contact with her; when they gave birth, they taught this practice to their young.[16]
The National Institutes of Health reported that capuchin monkeys preferred the company of researchers who imitated them to that of researchers who did not. The monkeys not only spent more time with their imitators but also preferred to engage in a simple task with them even when provided with the option of performing the same task with a non-imitator.[17]
[edit] Mating and the fight for supremacy
Individual reproduction is the most important phase in the proliferation of individuals or genes within a species: for this reason, there exist complex mating rituals, which can be very complex even if they are often regarded as fixed action patterns (FAPs). The Stickleback's complex mating ritual was studied by Niko Tinbergen and is regarded as a notable example of a FAP.
Often in social life, animals fight for the right to reproduce, as well as social supremacy. A common example of fighting for social and sexual supremacy is the so-called pecking order among poultry. Every time a group of poultry cohabitate for a certain time length, they establish a pecking order. In these groups, one chicken dominates the others and can peck without being pecked. A second chicken can peck all the others except the first, and so on. Higher level chickens are easily distinguished by their well-cured aspect, as opposed to lower level chickens. While the pecking order is establishing, frequent and violent fights can happen, but once established, it is broken only when other individuals enter the group, in which case the pecking order re-establishes from scratch.
[edit] Living in groups
Several animal species, including humans, tend to live in groups. Group size is a major aspect of their social environment. Social life is probably a complex and effective survival strategy. It may be regarded as a sort of symbiosis among individuals of the same species: a society is composed of a group of individuals belonging to the same species living within well-defined rules on food management, role assignments and reciprocal dependence.
When biologists interested in evolution theory first started examining social behaviour, some apparently unanswerable questions arose, such as how the birth of sterile castes, like in bees, could be explained through an evolving mechanism that emphasizes the reproductive success of as many individuals as possible, or why, amongst animals living in small groups like squirrels, an individual would risk its own life to save the rest of the group. These behaviours may be examples of altruism.[18] Of course, not all behaviours are altruistic, as indicated by the table below. For example, revengeful behaviour was at one point claimed to have been observed exclusively in Homo sapiens. However, other species have been reported to be vengeful, including reports of vengeful camels[19] and chimpanzees.[20]
Classification of social behavioursType of behaviour / Effect on the donor / Effect on the receiver
Egoistic / Increases fitness / Decreases fitness
Cooperative / Increases fitness / Increases fitness
Altruistic / Decreases fitness / Increases fitness
Revengeful / Decreases fitness / Decreases fitness
The existence of egoism through natural selection does not pose any question to evolution theory and is, on the contrary, fully predicted by it, as is cooperative behaviour. It is more difficult to understand the mechanism through which altruistic behaviour initially developed.
[edit] Social ethology and recent developments
In 1970, the English ethologist John H. Crook published an important paper in which he distinguished comparative ethology from social ethology, and argued that much of the ethology that had existed so far was really comparative ethology—examining animals as individuals—whereas, in the future, ethologists would need to concentrate on the behaviour of social groups of animals and the social structure within them.
Also in 1970, Robert Ardrey's book The Social Contract: A Personal Inquiry into the Evolutionary Sources of Order and Disorder was published.[21] The book and study investigated animal behaviour and then compared human behaviour to it as a similar phenomenon.
E. O. Wilson's book Sociobiology: The New Synthesis appeared in 1975, and since that time, the study of behaviour has been much more concerned with social aspects. It has also been driven by the stronger, but more sophisticated, Darwinism associated with Wilson, Robert Trivers, and William Hamilton. The related development of behavioural ecology has also helped transform ethology. Furthermore, a substantial reapprochement with comparative psychology has occurred, so the modern scientific study of behaviour offers a more or less seamless spectrum of approaches: from animal cognition to more traditional comparative psychology, ethology, sociobiology, and behavioural ecology. Sociobiology has more recently[when?] developed into evolutionary psychology.
[edit] Tinbergen's four questions for ethologists
Main article: Tinbergen's four questions
· Development — How does the behaviour change with age, and what early experiences are necessary for the animal to display the behaviour?
· Evolutionary history — How does the behaviour compare with similar behaviour in related species, and how might it have begun through the process of phylogeny?
These explanations are complementary rather than mutually exclusive—all instances of behaviour require an explanation at each of these four levels. For example, the function of eating is to acquire nutrients (which ultimately aids survival and reproduction), but the immediate cause of eating is hunger (causation). Hunger and eating are evolutionarily ancient and are found in many species (evolutionary history), and develop early within an organism's lifespan (development). It is easy to confuse such questions—for example, to argue that people eat because they're hungry and not to acquire nutrients—without realizing that the reason people experience hunger is because it causes them to acquire nutrients.[