Option E.3 – Innate and Learned Behaviour
E.3.1 – Distinguish between innate and learned behaviour
Innate Behaviour – Behaviour that develops independently of the environmental context. It is present at or soon after birth.
Learned Behaviour – Behaviour that develops as a result of experience
E.3.2 – Design experiments to investigate innate behaviour in invertebrates, including either a taxis or a kinesis
Experiments can be done to test two types of behaviour in response to a stimulus.
Kinetic Movements
This is when the rate of movement is related to the intensity of the stimulus. However, the direction of this movement is random. For example, you may look at the speed at which an organism moves at higher and lower humidity, proximity to food, temperature, etc.
Example: Woolice and Humidity
In a Petri dish, you should aim to create a gradient of humidity in the atmosphere. In the more humid sections, they should become less active, whilst in the drier areas, their movements would become quicker. These movements would lead to more woodlice being found in the more humid areas. This is because when they are in the drier area, they would be more likely to move in to the more humid area due to their random movements, and would remain there after their movements slowed.
Aim: To investigate the effect of a humidity gradient on the distribution of woolice.
Risks: There are very few risks – good laboratory practice would remove any danger.
Method: Things to consider
- Petri dish choice chamber design
- How to maintain the humidity gradient
- Surface for the free movement of the woodlice
- Number of woolice used
- Frequency of recording data
- Environmental conditions for woodlice before experiment
- Other variables to control
- Can a data-logger be used?
- How long each trial should last
- How to treat the animals after the experiment
Data Recording, Presentation and Analysis:
- Use of a table for recording raw data
- Type of grph to make trends evident
- Statistical test that can be done
Discussion of Results
- Behavioural response: kinesis or taxis?
- Relate to actual living conditions of the woodlice
- Modifications to improve
- Other investigations based on the results
Tactic Movements
This is when the direction of the stimulus determines the direction of the response. An organism may move towards food or light
Example: Blowfly Larvae and Light
Some blowfly maggots have a positive response to light, whilst others have a negative one.
Aim: To investigate the response of blowfly larvae to light in different directions
Risks: Safety implications of light intensity (i.e. too bright may be damaging to eyes, too low may make it difficult to perform experiment safely). Possible contraction of infection from handling organisms.
Method: Things to consider include
- Environmental conditions of larvae before experiment
- Number of larvae needed
- How to remove light in the area
- An appropriate surface for the movement of larvae
- How to create a unilateral beam
- How to vary the direction and intensity of light
- Method for recording the direction of movement
- Other variables to control
- How long the investigation should last
- Can data-loggers be used
- How to treat the organisms after the experiment
Data Recording, Presentation and Analysis
- How to pool the data from different experiments
- Type of graph to make trends evident
- Statistical tests to be used
Discussion of Results
- Is the response positively or negatively phototactic?
- How does it relate to their real way of life?
- Ways to improve the method
- Further investigations based on results
Remember to consider how these responses and behaviours can improve the organisms chance of survivable and reproduction.
E.3.3 – Analyse data from invertebrate behaviour experiments in terms of the effect on chances of survival and reproduction
Woodlice
Woodlice are crustaceans, belonging to the same family as crabs and lobsters. They typically live under logs and stones, in bark crevices, among dead leaves and rotting plant material, and usually eat decaying vegetable material. They are nocturnal and forage when it is dark.
Since their skins are not waterproof, they are restricted to living in humid conditions. Their front five pairs of legs act as gills, and can only function when the environment is damp. As a result, if the area is too dry, or if they are submerged, they will suffocate or drown.
These things restrict the possible habitats and behaviours of the woodlice that allow them to survive and reproduce.
- Remain away from light in a humid environment
- Forage at night on walls, where they encounter fewer predators or drown under rain.
Bumble Bees
These visit flowers to collect nectar and pollen to be used as food. Evolution of both bees and flowers has provided them with mutual advantage. Flowers need to provide an abundance
Flowers need to provide an abundance of these nutrients at critical times in the bee’s lifecycle, such as during mating and rearing young. They must use foraging techniques that allow for the optimal amount of food to be collected. This involves developing flight paths that allow them to collect food effectively.
For the flowers, the bees are important for pollination and cross-pollination of the flowers.
E.3.4 – Discuss how the process of learning can improve the chances of survival
Learning is the process of changing behaviour in response to a development in the organism’s environment. It is part of the process of adapting to the changing circumstances of the environment, and can only be acquired through experience. As a result, two individuals of the same species may learn different things through having different experiences. Learning comes in a few forms:
Habituation
This is when the response of the organism is dulled, or decreased, as a result of repeated exposure to the stimulus. For example, a snail will eventually learn that it is not necessary to withdraw into its shell when it touches a leaf, realising that this poses no danger.
However, this is only learned after the snail touches the leaf a number of times, and each time sees that the leaf is not a threat. If the snail did not learn to ignore this stimulus, it would waste a lot of time withdrawing into its shell, which could be spent on more productive activity to increase its chances of survival and reproduction. This can also be applied to flocks of birds that feed on farmer’s crops: the farmers may install a bird scaring device that makes a loud, frightening sound. However, after repeatedly seeing that there is no actual danger with the sound, the birds learn to ignore it and will feed on the crops again.
Imprinting
This is when an organism forms an attachment with another organism during the early, receptive stage in their life. The bond is formed almost instantaneously at birth. In most cases, this would be with their mother, who will then teach them the necessary skills for survival, including communication and feeding.
Conditioning
This is when the learning is associated with a reward or punishment. This was investigated by Ivan Pavlov, as discussed in the next section. He demonstrated that if an unrelated stimulus is given with an unconditioned stimulus, the animal will learn to associate them and eventually have the same response to the unrelated stimulus, called a conditioned reflex.
Trial and Error
This behaviour has been investigated using mazes, where a wrong choice leads to no reward. If the animal can master it, they will find a reward at the end. Some animals learn to navigate them successfully more quickly than others.
The maze is learnt through exploration, with their curiosity maintained by rewards.
Insight
This is also called reasoning. It requires the ability recall data from past experiences, and make generalisations. We can also use information that we have learned without experiencing it. We can fall back on previous trial-and-error learning so that the same process does not have to be repeatedly experienced.
E.3.5 – Outline Pavlov’s experiments into conditioning of dogs
Pavlov’s investigations looked at the dog’s reflex response of salivation in the presence of food. The meat was the unconditioned stimulus, with the secretion of saliva being the unconditioned response.
The bell, on the other hand, was a neutral stimulus and the dog had no response to it. Pavlov combined this neutral stimulus with the unconditioned stimulus of the food by ringing the bell every time he presented the dog with meat. This was repeated over a few days, by which time the dog began to secrete saliva when the bell was rung, even though the meat had not been presented yet. The bell had become the conditioned stimulus and the salivation when the bell rang was the conditioned response.
The conditioned response comes because the dog learned to associate the ringing of the bell with the food, called classical conditioning.
However, unlike the unconditioned response, the conditioned response in not permanent. The learned behaviour will not stay with the animal for the rest of its life, but will eventually wear off once it is no longer paired with the unconditioned stimulus. In other words, the response becomes extinct.
Pavlov also found that if the two stimuli are once again paired together, this leads to the spontaneous recovery of the learned response. The individual does not completely forget the response, but will reinstate it more quickly than during the original conditioning.
These days, there are many laws that prevent unnecessary experimentation on animals, such as the ones undertaken by Pavlov. Despite these ethical issues, the investigations done in the past have still given us valuable insight into many areas.
E.3.6 – Outline the role of inheritance and learning in the development of birdsong in young birds
Birds use songs as their form of communication. They are able to vary their sound through movements of the head and opening and closing their mouth. Most birds are raised by their parents and hear their song. However, some species, like the cuckoo, will never hear their parent’s song. Nevertheless, cuckoos will still develop their own song – they do not simply use that of their adopted parents. This shows that birds do not learn to sing, but that it is inherited.
Despite this, research has shown that a young bird will only inherit a template, and their song will be altered as the listen to their parents and refine it to be more like their parents’.