Innate and learned behavior
Innate and learned behavior
Option E.3
Assessment
Statements
E.3.1 Distinguish between innate and learned behaviour.
E.3.2 Design experiments to investigate innate behaviour in invertebrates, including either a taxis or a kinesis.
E.3.3 Analyse data from invertebrate behaviour experiments in terms of the effect on chances of survival and reproduction.
E.3.4 Discuss how the process of learning can improve the chance of survival.
E.3.5 Outline Pavlov’s experiments into conditioning of dogs.
E.3.6 Outline the role of inheritance and learning in the development of birdsong in young birds.
Two types of scientists
Ethologists
study the behavior of animals in their natural environment
Examine patterns of behavior that affect an animal’s life
Psychologists
Study the behavior of animals in an artificial environment
Collect data on learning and motivation that could never be measured in the natural environment
Etymology ethologist
from Greek: ἦ θος , ethos , "character"; and -λογία , -logia
psychologist
Ancient Greek
ψυχή (psukhē),
“‘ soul ’”) + logia (“‘study of ’”)
Innate behavior
Develops independently of environmental context
Spider spins web correctly the first time
Infants suckle innately
Controlled by genes and inherited from parents
Some performed in certain order
Mating behavior of the three-spined stickleback fish
Learned behavior
Not genetically programmed
Process of gaining knowledge or skills or modifying existing knowledge or skills
Learning can only be measured by performance
Ex. Pedal pushing results in gain of food
Behavior output is not always easily seen, therefore, learning is sometimes difficult to measure
Comparison
Innate behavior Learned behavior
Develops independently of the environmental context
Controlled by genes
Dependent on the environmental context of the animal for development
Not controlled by genes
Inherited from parents Not inherited from parents
Developed by natural selection
Increases chance of survival and reproduction
Develops by response to an environmental stimulus
May or may not increase chance of survival and reproduction
Investigating innate behavior in invertebrates
Innate behaviors can be measured as the animals respond to environmental stimuli
Two basic kinds of movement are seen in invertebrate animals:
Taxis
Kinesis
Taxis
A directed response to a stimulus
If the animal’s body is directed toward the stimulus, it has a positive response
If the animal’s body is directed away from the stimulus, it has a negative response
Taxes are identified by the type of stimuli to which the organism is responding
Chemotaxis: response to chemicals in the environment; experiments involving variation in pH, dissolved drugs, food, pesticides
Phototaxis: response to light; experiments involving different wavelengths of light, intensities, and different types of bulb
Gravitaxis: response to gravity; experiments with organism in container that is turned upside down or on a turntable
Rheotaxis: response to water current; experiment involving animals with and against current
Thigmotaxis: response to touch; experiment involving different types of material to touch an organism
Commonly used organisms
Planaria
Flatworm which lives in lakes and ponds under leaves and rocks and hides for protection
Active and move by contraction of muscle fibers in their body
Simple nervous system; eyespots which contain photoreceptors; chemoreceptors which respond to certain chemicals
(food)
Euglena
Single-celled protist
Has flagellum which propels it quickly through the water
Has an eyespot which is stimulated by light
Has chlorophyll
Kinesis
Movement in response to a nondirectional stimulus, such as humidity
Rate of movement of the animal depends on the intensity of the stimulus, not its direction
Animal does not move toward or away from the stimulus buy randomly until it is in a more comfortable spot
Orthokinesis: when an organism moves slowly or rapidly (changes speed) in response to the stimulus but 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
Commonly used organisms
Isopods (woodlice; rolly pollies)
Terrestrial crustaceans
Breath with gills; need moisture in order to breath
Live in damp places; die if exposed to dry conditions for a long period of time
Learning improves the chance of survival
Learning occurs most easily when it results in the animal’s survival
Imprinting – process by which young animals become attached to their mother within the first day or so after hatching or birth; assures that the young stay close to their mother for protection and as a source of food
Food hoarding – store food when it is plentiful and return when there is a shortage; allows them to stay nourished even in times of food shortages
Song – attracts a mate and deters rival males
How to get food
Mimicry
Pavlov and conditioning
Classical conditioning can be used to modify a reflex response
Russian physiologist Ivan Pavlov designed experiments to illustrate classical conditioning
His subjects were dogs
Salivation is a reflex response to the presence of food in the mouth
Food is unconditional stimulus which elicits salivation which is unconditional response
Neutral stimulation that Pavlov employed was the ringing of a bell
He rang the bell (conditioned stimulus) just before the dog tasted the food
After training, the could ring the bell (CS) and the dog would salivate (conditioned result)
Dog had learned to salivate to the neutral stimulus
Learning of birdsong in young birds
Each species of bird has a species-specific song which is inherited
Birds learn to improve the song they have inherited
Birds are able to sing due to their vocal organ, called the syrinx located at the bottom of their trachea
Birds control the pitch by altering the tension in the membranes of the syrinx
If birds are kept in a lab and denied any auditory stimulation, they produce a crude song
After hatching, there is a memorization phase in which the bird is silent but listening to the song of his species from adults (males)
He attempts to match his template to the full adult song
Phase if over within 100 days
(sensitive period)
2 nd phase is motor phase in which he practices singing, continuing to listen to his own song and match it to his father’s
As he becomes sexually mature, his song will become perfected and he will begin to search for a mate
Crude template is innate; adult song is learned
