Learning and Motivation Chapter 1 Introduction Learning to Change The Constancy of Change Earthquakes tsunamis other natural disasters are a part of life but we tend to regard them as an Aberration a brief disruption in a normally constant world BUT Change is the ONLY Constant The struggle to survive effort to cope with change climate change diseases faster predators population increase add stress on availability of resources Natural Selection Charles Darwin realized that all species of animals plants produced far more offspring that the environment can support competition of resources Mechanism for change breeder s practice of selectively mating animals w desireable characteristics in the wild NATURE is the breeder characteristics somehow passed from one generation to another they are beneficial detrimental or of no significance in environment Natural Selection Depends on variations among the members of species Darwin complex organs do not normally appear suddenly Ex Human Eye origin millions yrs ago w appearance of light sensitive cells under skin through additional variations natural selection light detecting organ more complex Ex Human Brain primitive nervous system jellyfish then first true brains worms NS demands devices good enough to aid SURVIVAL takes generations to develop sophisticated tools Important environmental change climate change Ex over past 25 yrs Scotland is getting warmer consequently wool sheep got smaller changes in terrain Ex dark lizards in dark places white lizards in light places pollution Ex light moths light trees trees got polluted darker moths on dark trees Predators important part of animal s surroundings and Changes in predator s play important rold in NS Swanne Gordon Guppies Those evolved to adapt to predators had 50 survival rate over guppies used to safety Changes in environment affect Human Characteristics skin color due to amt of melatonin screens out suns harmful rays more melatonin darker more sunscreened out Diseases global epidemics increases in international trade bring vectors carriers of disease failure in gov to monitor legal illegal imports makes pandemic likely when it happens those individs who have genetic features that convey resistance immunity will survive pass on advantage to offspring No change in environment No change in species Ex alligators stayed same for 200 mill yrs b c environment ponds never changed Evolved Behavior Natural Selection produces repertoir of largely innate adaptive forms of behavior that help organisms cope w demands of their particular environment 3 Categories of Behavior 1 Reflexes 2 Modal Action Patterns 3 General Behavior Traits Reflex Relationship b w a specific event a simple response to that event ex tendency to blink when a speck of dirt hits your eye reflex is NOT the eyeblink itself but the relation b w speck of dirt eyelid either present at birth or appear at predictable stages in development ALL animals have reflexes Many reflexes serve to PROTECT individuals from injury Ex Pupillary Reflex Iris contracts or relaxes in response to changes in light The Sneeze irritants dust pollution expelled from nose and lungs Vomit Reflex removes toxic substances from stomach Reflex Arc Event excites sensory neurons that carry impulse to spinal cord THEN Impulse is transmitted to an interneuron THEN Impulse is transmitted to effector neurons THEN Impulse is carried by effector neurons to muscle tissue glands THEN They produce simple response Reflexes Food Consumption Rooting Reflex touch baby s cheek she turns to find mother s nipple Sucking Reflex when nipple touches baby s lips Salivary Reflex triggered by food in mouth begins process of digestion saliva triggers swallowing swallowing triggers peristalsis peristalsis rhythmic motion of lining of esaphogus that carries food to stomach Eating chain of reflexes We tend not to notice useful reflexes until they fail to function properly Not all reflexes are useful allergies seizures Reflexes are subject to natural selection Reflexes are highly stereotypic consistant in form frequency strength time of appearance during development reflexes change across a life span Modal Action Pattern MAP A series of related acts found in all or nearly all members of a species resemble reflexes in that they have strong genetic basis display relatively little variability often reliably elicited by a releaser particular kind of event differ from reflexes in that they involve entire organism instead of a few muscles glands more complex consist of long series of reflex like acts more variable than reflexes still rather stereotypic b c of complexity utility MAPS appear to be thoughtful BUT THEY ARE NOT MAP s evolve through Natural Selection b c they contribute to the survival of the species helping individ Find food deal w threats to safety pass their genes on to the next generation Many Modal Action Patterns exist to protect individ From environmental threats Predators Seasonal Changes Reproduction MAP s Ex peacock flaunts pretty feathers bighorn sheep bash head w rival for female MAP s also govern care rearing of young Ex birds feed young until they leave the nest MAP s in humans Researchers maintain that there are no true modal action patters in people General Behavior Traits The tendency to engage in a certain kind of behavior Ex tendency to be shy vs outgoing Aggressive vs mild mannered Adventurous vs cautious Anxious vs relaxed Obsessive compulsive vs impulsive Behavior traits occur in a wide variety of situatons as opposed to MAP s which are elicited by specific kinds of environmental events releasers ex under certain circumstances unpleasant experiences will reliably produce aggressive behavior in animals ppl unpleasant experiences includes a lot of things electric shock spray cold water etc MAPs are not released by so many diff kinds of events Behavior traits are more viable than modal action patterns Heredity plays important role Ex selective breeding has produced strains of animals differing in fearfulness excitability aggressiveness activity level drug abuse etc Researchers can use genetic engineering to demonstrate the role of genes in behavior traits Genes play important role in ppl fearfulness excitability aggressiveness activity level drug abuse risk taking etc Thanks to genetic variation natural selection adaptive forms of behavior reflexes MAP s behavior traits spread throughout a species and help it survive Limits of Natural Selection chief problem SLOW