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E3. Innate and Learned Behaviour 15/02/2012 06:31:00 Option E: Neurobiology and Behaviour E3: Innate and Learned Behaviour Orange book pg. 306-307 Green book pg. 283-285 E3.1 Distinguish between innate and learned behaviour. Innate behaviour develops independently of the environmental context, whereas learned behaviour develops as a result of experience. E3.2 Design experiments to investigate innate behaviour in invertebrates, including either a taxis or a kinesis. Examples include: Taxis – Planaria more towards food (chemotaxis) and Euglena move towards light (phototaxis). Kinesis – woodlice move about less in optimum (humid) conditions and more in an unfavourable (dry) atmosphere. E3.3 Analyse data from invertebrate behaviour experiments in terms of the effect on chances of survival and reproduction. E3.4 Discuss how the process of learning can improve the chance of survival. E3.5 Outline Pavlov’s experiments into conditioning of dogs. The terms unconditioned stimulus, conditioned stimulus, unconditioned response and conditioned response should be included. E3.6 Outline the role of inheritance and learning in the development of birdsong in young birds. E3.1 Types of Behaviour 15/02/2012 06:31:00 E3.1 Distinguish between innate and learned behaviour. Innate behaviour develops independently of the environmental context, whereas learned behaviour develops as a result of experience. Orange book pg. 306-307 Green book pg. 283 Worksheet: “The Components of Behaviour” Innate Behaviour View the animation: http://www.yteach.ie/page.php/resources/view_all?id=navigation_migration_eth ology_taxis_taxes_tropism_stimulus_effector_involuntary_reflex_instinct_so ciety_aphasia_phototaxis_thermotaxis_neocortex_migration_brain_communica tion_habituation_territorial_behaviour_maternal_behaviour&from=search Page 4: Innate Behaviour Username: Biologyhelp Password: Ilovebiology Innate behaviour develops independently of environmental context. A spider spins a web correctly the very first time. No trial-and-error learning is taking place. Innate behaviours are controlled by genes and inherited from parents. A wasp builds a next which is characteristic of its species. A termite build a characteristic mound. Scientists familiar with insects can tell which insect built a next or mound by looking at its shape. These are genetically programmed behaviours which ensure the survival of the animal. A simple version of song is innate in birds. Sucking behaviour is innate in human infants. Some innate behaviours are performed in a certain order. A classic example of an innate sequence of behaviours is seen in the mating behaviour of the threespined stickleback fish (see diagram below). Mating begins with the male doing a zigzag dance when he sees the female. This dance attracts the female’s attention. She follows the male as he leads her to the nest he has constructed in the bed of the river. He backs out of the next and the female enters. He vibrates his body at the entrance to the next and the female releases her eggs. She leaves the nest and the male enters. He releases his sperm cells which fertilise the eggs. This behaviour is as specific to this species as the number of spines they have on their back. “The mating behaviour of the three-spined stickleback fish” Learned Behaviour Learned behaviour is not genetically programmed. You learned to read a book, how to ride a bike, how to tie your shoes. All of these activities result in new knowledge that did not previously exist or a new skill that you did not originally possess. Learned behaviour can be defined as the process of gaining new knowledge or skills or modifying existing knowledge or skills. You may know how to read at one level when you are six years old, but you will improve that skill with more practice and schooling. View the animation: http://www.yteach.ie/page.php/resources/view_all?id=navigation_migration_eth ology_taxis_taxes_tropism_stimulus_effector_involuntary_reflex_instinct_so ciety_aphasia_phototaxis_thermotaxis_neocortex_migration_brain_communica tion_habituation_territorial_behaviour_maternal_behaviour&from=search Page 6. Elementary and Insight Learning: Instrumental Conditioning in the Rat Username: Biologyhelp Password: Ilovebiology Youtube video: “Husky – I Love you” http://www.youtube.com/watch?v=qXo3NFqkaRM How do we know that learning in animals has really occurred? Learning can only be measured by performance. Learning can be explained as change in performance that we are sure is stored in the nervous system as memory. For example, a rat learns that pressing a pedal releases food. The rat originally pressed the pedal by accident during exploration of its cage. After the pellet of food was released over and over again, the rat learned to associate the food with the pedal. Later pushing the pedal to get food became a deliberate act. This is performance which indicates learning. Behaviour output is not always easily seen. This is why learning is sometimes difficult to measure. This table summarises a comparison on innate and learned behaviour. Innate behaviour Learned behaviour Develops independently of the environmental context Dependent on the environmental context of the animal for development Controlled by genes Not controlled by genes Inherited from parents Not inherited from parents Developed by natural selection Develops by response to an environmental stimulus Increases chance of survival and May or may not increase chance of reproduction survival and reproduction TOK: Watch the Youtube video: “Science in Action: Facial Expressions” http://www.youtube.com/watch?v=5G6ZR5lJgTI As you watch, consider the following questions: 1. Does experimentation under lab conditions affect responses of humans? 2. Could these limitations apply to studies of other species or phenomena? 3. Does the observer, by the act of observing, change the outcome of the investigation? 4. Why did the blind athletes make for good study subjects of this phenomenon? 5. What conclusions were drawn in this study? Just for a laugh View the Youtube video: “Spiders on Drugs” http://www.youtube.com/watch?v=sHzdsFiBbFc E3.2 Investigating Behaviour 15/02/2012 06:31:00 E3.2 Design experiments to investigate innate behaviour in invertebrates, including either a taxis or a kinesis. Examples include: Taxis – Planaria more towards food (chemotaxis) and Euglena move towards light (phototaxis). Kinesis – woodlice move about less in optimum (humid) conditions and more in an unfavourable (dry) atmosphere. Orange book pg. 306 Green book pg. 283-284 Biozone Worksheet: “Simple Behaviours” Investigating innate behaviour in invertebrates Animals orient in different ways to their diverse environments. They survive better in some places than others. Food may be more plentiful in one area, better protection available in another area, humidity levels higher in another. When studying simple invertebrate animals, innate behaviours can be measured as the animals respond to environmental simuli. Two basic kinds of movement are seen in invertebrate animals: taxi and kinesis. Taxis A taxis (plural: taxes) is a directed response to stimulus. If the animal’s body is directed toward the stimulus, we say it has a positive response. If the animal’s body is directed away from the stimulus, we say it has a negative response. For example, if an animal moves away from light it exhibits a negative phototaxis. If it moves towards the light, it exhibits positive phototaxis. Taxes are identified by the type of stimuli to which the organism is responding. View the animation: http://student.ccbcmd.edu/courses/bio141/lecguide/unit2/bacpath/contactcell _flag.html Page 2: Environment and Behaviour: Taxes in Amoeba and Paramecium Username: Biologyhelp Password: Ilovebiology Watch the Youtube video: “Paramecium Feeding” http://www.youtube.com/watch?v=saLYHUs6cWk Chemotaxis The response to chemicals in the environment. Organisms in water can move towards or away from food or other chemicals which are dissolved in their aquatic medium. When exploring chemotaxis, experiments can be performed which vary the pH, concentration of dissolved drugs, food or pesticides. View the animation: “Chemotaxis” http://www.gluegrant.org/chemotaxis.htm This is an example of chemotaxis inside the body when injury occurs to tissue. View the animation: “Bacteria using chemotaxis and motility to contact host cells” http://student.ccbcmd.edu/courses/bio141/lecguide/unit2/bacpath/contactcell _flag.html This illustrates how some bacteria remain in the bladder and are not flushed out using chemotaxis. Phototaxis The response to light. Experiments can be performed using different wavelengths of light, different light intensities and different types of bulbs (UV or fluorescent). This two Youtube videos show phototaxis in animals: Nematode: http://www.youtube.com/watch?v=7-ZYdtCAF5U Earthworms: http://www.youtube.com/watch?v=9696M3VSePo Were these responses positive or negative phototaxes? Gravitaxis The response to gravity. Methods can be devised to measure the response to gravity if organisms are put into a container that is then placed upside down. Placing organisms on slowspinning turntables may also disrupt the normal pull of gravity. Thigmotaxis The response to touch. Some organisms respond to touch e.g. creeping vines will curl around the object they are growing up. The response to touch it for a small branch of the vine to curl around an object to support the vine. View the animation: http://www.yteach.ie/page.php/resources/view_all?id=information_stimulus_ph ytochrome_genetic_information_warning_signals_alarm_signals_animals_mating _behaviour_behaviour_genetic_information_communication_information_trans mitters&from=search Page 5. Information in nature: Tropisms and Taxes Username: Biologyhelp Password: Ilovebiology Experimenting Planaria is an interesting flatworm which lives in ponds and lakes. They are quite active and move by contraction of muscle fibres in their body. They have a simple nervous system and at the anterior end are two eyespots which contain photoreceptors stimulated by light. Also in the anterior end are chemoreceptors which respond to certain chemicals. Planaria is negatively photaxic, since it lives under leaves and rocks and hides for proctection. It is positively chemotaxic to food that it likes to eat, such as raw liver (raw liver would be similar to dead fish in its natural habitat). Interesting studies could include Planaria’s response to different wavelengths of light, how fast it moves towards different food substances (cm min -1), or response to temperature gradient or different concentrations of pesticide. Euglena is single-cells protist (protoctist). It has a flagellum which propels it quickly through the water. It also has an eyespot a the anterior end which is stimulated by light. Euglena can make its own food by photosynthesis since it contains molecules of chlorophyll. It is positively phototaxic since it needs light to perform photosynthesis. Euglena could be tested to determine if it responds to different wavelengths of light. Kinesis Kinesis is a movement in response to a non-directional stimulus, such as humidity. The rate of movement of the animal depends on the intensity of the stimulus, not its direction. It differs from taxis in that the animal does not move towards or away from the stimulus. If the animal is in an environment, which is not suitable, it moves rapidly but randomly (with no direction) until it is in a more comfortable spot. If it is in its ‘comfort zone’, its movements slow down. Slow movement is likely to keep the organism in the condition that it prefers. Orthokinesis When an organism moves slowly or rapidly (changes speed) in response to the stimulus but it does not move towards the stimulus. Klinokinesis When an organism turns slowly or rapidly in response to the stimulus but it does not move towards the stimulus. Isopods are terrestrial crustaceans which can be used to study kinesis. Even though they live on land, they breathe with gills and need moisture in order to breathe. Isopods live in damp places. They die id exposed to dry conditions for a long period of time. Isopods show kinesis to humidity. When placed in a damp environment, they move slowly. When placed in a dry environment, they move quickly. Moving quickly makes it more likely that they will get out of the dry air. Consequently, the isopod in the damp place will remain in that spot for which it is well suited. The isopod in the dry conditions may find a damp spot during its increased random movement. The minute it senses a damp environment, it random movements slow down. Woodlice are often used to study kinesis E3.3 Behaviour & Survival 15/02/2012 06:31:00 E3.3 Analyse data from invertebrate behaviour experiments in terms of the effect on chances of survival and reproduction. *This is most likely to be asked as a data analysis question. Orange book pg. 306-307 Green book pg. 284 What do invertebrate behaviour experiments tell us about survival and reproduction? An experiment was set up to investigate the effect of humidity on the distribution of isopods. A pair of Petri dished were set up; one chamber containing a drying agent (CaCl2) and the other with wet towels (as shown below). 10 individuals were placed in each chamber and the chambers closed with rubber stoppers. The number of organisms in each chamber was counted every 5 mins. The investigation was carried out twice. As a control, a set of paired Petri dished which have no difference in humidity were set up. Results The results obtained are shown in the following tables. Analysing the data Firstly we need to use statistical analysis to determine if the differences are significant. For example, the chi square statistical test can be used on data to determine if the difference between the data from experiments conditions are statistically different from data from controls. Secondly, we can draw conclusions based on the statistical analysis of the data. The behaviour of the isopods is to move randomly and quickly in a dry environment until they finally come to rest in the humid environment. Humidity is important to the survival of isopods and their ability to reproduce. The outer covering of isopods (exoskeleton) lacks a waterproof waxy cuticle (as found in many land-dwelling groups) so the animal is highly subject to desiccation (drying out). Quick random movements enable the isopod to find itself in a humid environment. This ensures survival and enhances the ability to reproduce. Natural selection favours isopods which show this response. E3.4 Learning and Survival 15/02/2012 06:31:00 E3.4 Discuss how the process of learning can improve the chance of survival. Orange book pg. 306-307 Green book pg. 284 View the Youtube videos: “The amazing intelligence of crows” http://www.youtube.com/watch?v=bXQAgzfwuNQ “Chimpanzee and Tool Use” http://www.youtube.com/watch?v=Nh9XL08Akwc When we talk about learning we mean that new knowledge or skill has been acquired. Learning occurs most easily when it results in improving the animal’s survival. Some special learning abilities which improve survival are imprinting, food hoarding and song. Imprinting is the process by which young animals become attached to their mother within the first day or so after hatching or birth. This is why a line of ducklings follow their mother. Imprinting assures that the young stay close to their mother for protection and as a source of food. This tremendously improves their chance of survival. Many animals store food when it is plentiful and return to the hoard of food when there is a shortage. Squirrels hoard nuts. Moles bite and paralyse worm and them alive in different places underground for days. They retrieve them when they are ready to eat. Hoarding food is an excellent strategy learned by animals – it allows them to stay nourished even in times of food shortages. Birdsong is also learned. If a young male sparrow hears an adult song within its first 100 days of life, it will sing a full adult song the next year. This song has two functions. It attracts a mate and deters rival males. The sparrow with the best song promotes survival of his particular genes. Other examples of learning which enhance survival are: Grizzly bears learning to catch slippery salmon in rushing river waters Chimpanzees learning to stick a branch into a termite nest, pull it out and eat the termites. Grizzly bears learn from their mothers, chimpanzees learn from trial and error. Obviously, both of these examples improve the chances of survival since they are learned strategies for obtaining food from difficult places. Although most learning increases the chances of survival, some animals are tricked into false learning through mimicry of their prey. One butterfly which has a bad tase is mimicked by another butterfly which does not taste bad at all. Some snakes imitate the poisonous red coral snake so they do not get eaten. E3.5 Pavlov’s Experiments 15/02/2012 06:31:00 E3.5 Outline Pavlov’s experiments into conditioning of dogs. The terms unconditioned stimulus, conditioned stimulus, unconditioned response and conditioned response should be included. Orange book pg. 307 Green book pg. 284 Biozone Worksheet: “Learned Behaviour” Visit the game: “Can you make a dog drool” http://nobelprize.org/educational/medicine/pavlov/pavlov.html Watch the Youtube videos: “Eddie Izzard – Pavlov’s Cat” http://www.youtube.com/watch?v=whwiMrBNWCA “Operant Conditioning” http://www.youtube.com/watch?v=I_ctJqjlrHA “Positive Reinforcement – The Big Bang Theory” http://www.youtube.com/watch?v=JA96Fba-WHk The Skinner Box: animation to see if you can be ‘conditioned’ http://www.kscience.co.uk/animations/anim_5.htm Pavlov and conditioning Classical conditioning can be used to modify a reflex response. In classical conditioning experiments, the subject responds to a stimulus in a new way. For example, in humans, blinking is a reflex response. If you wave your hand suddenly in front of a subject’s face, they will automatically blink. They waved hand is called the unconditional stimulus (UCS) because it unconditionally stimulates the eye-blink response. The eye-blink is called the unconditioned response (UCR). After training, it is possible to elicit the reflex response (eyeblink) with a new and neutral stimulus (NS). First, the neutral stimulus (e.g. a musical note) is introduced. The subject will probably not blink. Next the subject is given a period of training: the musical note is sounded immediately before a hand is waved in front of the subject’s eye. Eventually the subject responds with an eye-blink to just the musical note. After this has occurred, the musical note is called the conditioned stimulus (CS) and the eye-blink in response to the musical note is called the conditioned response (CR). The subject is now responding to a musical note in a new way. The Russian physiologist Ivan Pavlov designed experiments to illustrate classical conditioning. His subjects were dogs. Salivation in dogs is a reflex response to the presence of food in the mouth. The unconditioned stimulus (UCS) of food elicits the unconditioned response (UCR) of salivation. The neutral stimulus (NS) that Pavlov employed was the ringing of a bell. He rang the bell just before the dog tasted the food. After training, he could ring the bell (CS) and the dog would salivate (CR). The dog had learned to salivate to the neutral stimulus (NS) alone. E3.6 Birdsong 15/02/2012 06:31:00 E3.6 Outline the role of inheritance and learning in the development of birdsong in young birds. Orange book pg. 307 Green book pg. 284-285 Biozone Worksheet: “Learning to Sing” Learning of birdsong in young birds Watch the video: “Bird Song and Culture” http://www.youtube.com/watch?v=Hm_peAugIk0 “Bird sounds from the lyre bird - David Attenborough - BBC wildlife” http://www.youtube.com/watch?v=VjE0Kdfos4Y Are you able to tell the difference between bird songs? Each species of bird has a species-specific song, which is inherited. Birds of one species have a varied song just as we have variations in the colour of our eyes. However, birds can also learn to improve the song they have inherited. Thus, birdsong has both inherited and learned components. Imprinting: http://www.youtube.com/watch?v=2UIU9XH-mUI Birds are able to sing due to their vocal organ, called the syrinx. The syrinx is a bony structure at the bottom of their trachea (windpipe). In human, the larynx (voice box) is at the top of the trachea. The bird forces air past a membrane in the syrinx, which vibrates and results in sound. Birds control the pitch by altering the tension in the membranes of the syrinx. They control the volume of the song by altering the flow of air. Birdsong is a well studies example of animal behaviour. Singing is an important business for the male bird. He attracts a mate with his song and deters male rivals. Generally females do not sing. Studies of song learning have shown that birds hatch with what is called a ‘crude template’. Evidence for a template is shown by experimental data: if birds are kept in a laboratory and denied any auditory stimulation, they produce a very crude song. This crude song is speciesspecific. The crude song of a warbler can be distinguished from the crude song of a sparrow. With an acoustical spectrosope, it is possible to accurately measure the difference. This data is evidence that the template is inherited. All of the next stages of birdsong development are learned. After hatching, there is a memorization phase. In this phase, the bird is silent but listening to the song of his species from adults. The hatchling is modifying the inherited template. As he is listening, he is attempting to match his template to the full adult song. It is a type of memorization. This memorization phase is over at about 100 days of age. If a male bird does not hear the adult song within 100 days, he will not modify the template that he has inherited. The first 100 days is called the sensitive period. The second phase is a motor phase in which the young bird practices singing the song that he has heard. He hears himself singing and begins to shape his song to match what he has heard from the adult, usually his father. The bird must hear his own song in order to sing an accurate adult song. (Experiments have been done which show that is a bird is deafened after 100 days, he will only sing the crude template of the song). As he becomes sexually mature, his song will become perfected and he will begin to search for a mate. The crude template is a good example of innate learning while the adult song is an example of how learned behaviour can help an animal acquire new skills.