Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 51 Behavioral Ecology

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 51.1: Behavioral ecologists distinguish between proximate and ultimate causes of behavior The scientific questions that can be asked about behavior can be divided into two classes – Those that focus on the immediate stimulus and mechanism for the behavior – Those that explore how the behavior contributes to survival and reproduction

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings What Is Behavior? Behavior – Is what an animal does and how it does it – Includes muscular and nonmuscular activity Figure 51.2 Dorsal fin Anal fin

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Learning – Is also considered a behavioral process

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Proximate and Ultimate Questions Proximate, or “how,” questions about behavior – Focus on the environmental stimuli that trigger a behavior – Focus on the genetic, physiological, and anatomical mechanisms underlying a behavioral act

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ultimate, or “why,” questions about behavior – Address the evolutionary significance of a behavior

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Imprinting Imprinting is a type of behavior – That includes both learning and innate components and is generally irreversible

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Conservation biologists have taken advantage of imprinting – In programs to save the whooping crane from extinction Figure 51.6

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 51.2: Many behaviors have a strong genetic component Biologists study the ways both genes and the environment – Influence the development of behavioral phenotypes Behavior that is developmentally fixed – Is called innate behavior and is under strong genetic influence

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Migration Many features of migratory behavior in birds – Have been found to be genetically programmed Figure 51.8

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Animal Signals and Communication In behavioral ecology – A signal is a behavior that causes a change in another animal’s behavior Communication – Is the reception of and response to signals

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Animals communicate using – Visual, auditory, chemical, tactile, and electrical signals The type of signal used to transmit information – Is closely related to an animal’s lifestyle and environment

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Chemical Communication Many animals that communicate through odors – Emit chemical substances called pheromones

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Genetic Influences on Mating and Parental Behavior A variety of mammalian behaviors – Are under relatively strong genetic control

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Learning Learning is the modification of behavior – Based on specific experiences Learned behaviors – Range from very simple to very complex

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Habituation – Is a loss of responsiveness to stimuli that convey little or no information

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Associative Learning In associative learning – Animals associate one feature of their environment with another

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Classical conditioning is a type of associative learning – In which an arbitrary stimulus is associated with a reward or punishment Figure Before stimulus Influx of water alone Influx of alarm substances Influx of pike odor Day 1 Day 3 Control group Experimental group Relative activity level

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Operant conditioning is another type of associative learning – In which an animal learns to associate one of its behaviors with a reward or punishment Figure 51.16

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cognition and Problem Solving Cognition is the ability of an animal’s nervous system – To perceive, store, process, and use information gathered by sensory receptors

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 51.4: Behavioral traits can evolve by natural selection Because of the influence of genes on behavior – Natural selection can result in the evolution of behavioral traits in populations

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 51.5: Natural selection favors behaviors that increase survival and reproductive success The genetic components of behavior – Evolve through natural selection Behavior can affect fitness – Through its influence on foraging and mate choice

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Foraging Behavior Optimal foraging theory – Views foraging behavior as a compromise between the benefits of nutrition and the costs of obtaining food

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Mating Behavior and Mate Choice Mating behavior – Is the product of a form of natural selection call sexual selection

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings In many species, mating is promiscuous – With no strong pair-bonds or lasting relationships

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings In monogamous relationships – One male mates with one female Figure 51.25a (a) Since monogamous species, such as these trumpeter swans, are often monomorphic, males and females are difficult to distinguish using external characteristics only.

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings In a system called polygyny – One male mates with many females – The males are often more showy and larger than the females Figure 51.25b Among polygynous species, such as elk, the male (left) is often highly ornamented. (b)

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings In polyandrous systems – One female mates with many males – The females are often more showy than the males Figure 51.25c (c) In polyandrous species, such as these Wilson’s phalaropes, females (top) are generally more ornamented than males.

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The needs of the young – Are an important factor constraining the evolution of mating systems The certainty of paternity – Influences parental care and mating behavior

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings In species that produce large numbers of offspring – Parental care is at least as likely to be carried out by males as females Figure Eggs

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sexual Selection and Mate Choice In intersexual selection – Members of one sex choose mates on the basis of particular characteristics Intrasexual selection – Involves competition among members of one sex for mates

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Such competition may involve agonistic behavior – An often ritualized contest that determines which competitor gains access to a resource Figure 51.30

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Morphology affects the mating behavior – In isopods of the same species that are genetically distinct Figure Large Paracerceis  males defend harems of females within intertidal sponges.      Tiny  males are able to invade and live within large harems.  males mimic female morphology and behavior and do not elicit a defensive reponse in  males and so are able to gain access to guarded harems.

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 51.6: The concept of inclusive fitness can account for most altruistic social behavior Many social behaviors are selfish Natural selection favors behavior – That maximizes an individual’s survival and reproduction

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Altruism On occasion, some animals – Behave in ways that reduce their individual fitness but increase the fitness of others This kind of behavior – Is called altruism, or selflessness

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Hamilton’s Rule and Kin Selection Hamilton proposed a quantitative measure – For predicting when natural selection would favor altruistic acts among related individuals

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The three key variables in an altruistic act are – The benefit to the recipient – The cost to the altruist – The coefficient of relatedness

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The coefficient of relatedness – Is the probability that two relatives may share the same genes Figure Parent AParent B  OR Sibling 1 Sibling 2 1 / 2 (0.5) probability

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Natural selection favors altruism when the benefit to the recipient – Multiplied by the coefficient of relatedness exceeds the cost to the altruist This inequality – Is called Hamilton’s rule

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Kin selection is the natural selection – That favors this kind of altruistic behavior by enhancing reproductive success of relatives

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Social Learning Social learning – Forms the roots of culture Culture can be defined as a system of information transfer through observation or teaching – That influences the behavior of individuals in a population

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings No other species – Comes close to matching the social learning and cultural transmission that occurs among humans Figure 51.38

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Evolution and Human Culture Human culture – Is related to evolutionary theory in the distinct discipline of sociobiology

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Human behavior, like that of other species – Is the result of interactions between genes and environment However, our social and cultural institutions – May provide the only feature in which there is no continuum between humans and other animals