210 likes | 290 Views
Learning. A “ relatively permanent change in behavior as a result of experience ”. what is learning? which behaviors are learned? why learn or when will learning evolve?. Learning is a proximal cause of animal behavior because learning itself is
E N D
Learning A “relatively permanent change in behavior as a result of experience” • what is learning? • which behaviors are learned? • why learn or when will learning evolve?
Learning is a proximal cause of animal behavior because learning itself is a strategy/trait subject to natural selection Learning is a tool that allows individuals to adjust their behavior to the local state of their world – i.e., to the set of local spatial, temporal, and social circumstances
A simple experimental example Can fish learn about predation risk in a body of water through chemical cues? 1) They react with an appropriate anti-predatory behavior 2) They retain this reaction for a period of time
Tissue extraction TSE Distilled Water (DW) + + Pike cues PO Pike cues PO Farm raised juvenile brown trout
Short-term effects
21-days later A “relatively permanent change in behavior as a result of experience”
Socially acquired predator avoidance Eagle alarm Leopard alarm Snake alarm
< 5 6-10 11-15 >15 Infants N=24 Raptors Non-raptors Vulture Bee-eater Goshawk Snake Bateleur Tawny Fish Eagle Eagle Eagle Juveniles N=53 Non-raptors Raptors Vulture Stork Bustard Goshawk Snake Bateleur Martial Crowned Tawny Fish Harrier Owl Eagle Eagle Eagle Eagle Eagle Adults N=55 How do infants come to recognize the association between an alarm call and 1-2 predators? Raptors Non-raptors Vulture Goshawk Snake Martial Crowned Tawny Fish Hawk Owl Eagle Eagle Eagle Eagle Eagle Eagle
100% 4% 64% 3% 14% Probability of adult alarm calling after infant alarm call by avian species – Reinforcers?
100 Responses of infants to playbacks of adult alarm calls 100 Number of infants responding correctly incorrectly 100 3/4 4/5 5/6 6/7
Learning curves associated with locating and extracting nectar as a function of experience
songs per min Simple recognition learning – animals learn to recognize events they are simply exposed to In this example, birds learn who their neighbors are and associate them to a particular place – the territory boundary “Dear-enemy” effect
Learning is a tool that allows individuals to adjust their behavior to the local state of their world – i.e., to the set of local spatial, temporal, and social circumstances -Where is food and what make-up is it? - Who are my territorial neighbors – do I recognize them? - What predators are nearby and what are their intentions? • - recognizing kin from non-kin • social hierarchies: recognizing strangers from non-strangers • remembering past interactions (winners and losers) • recognizing high quality mates
Dave Stephen’s Model experience is useful within generation, and learning anew is favored each generation ignore experience If offspring’s environment is nearly identical, fixed genetic transmission is favored over costly learning Low High ignore experience experience in the past is not useful it is useful Evolution of Learning Low learn Between-generation Predictability ignore experience High Within-lifetime Predictability
Dave Stephen’s Model High within-lifetime predictability Low between-generation predictability learn e.g. members of each new generation may find food in different places, but there is always value in being able to learn where food is This differs from classical views of learning that assumed: (1) The ability to learn is an unadulterated good (2) Learning abilities are human-like: general and unlimited
Br d Parasitism
Br d Parasitism
Summary: • - Learning is a likely element of proximal causation for many of the • behaviors discussed in the remainder of the class • The entire learning process is under evolutionary selection pressure • We can broadly understand the evolution of learning in response to the • predictability of an organism’s environment in its own lifetime and beyond • and we can ask detailed questions about the evolution of learning under • specific contexts with a cost-benefit analysis