Chapter 35 Behavioral Adaptations To The Environment

Chapter 35Behavioral Adaptationsto the EnvironmentPowerPoint Lectures forBiology: Concepts & Connections, Sixth EditionCampbell, Reece, Taylor, Simon, and DickeyLecture by Brian R. ShmaefkyCopyright 2009 Pearson Education, Inc.

Introduction: Of Mice and Monogamy Behavior encompasses a wide range of activities Scientists study the mechanisms of behavior in anevolutionary context Learning has genetic and environmental behavioralaspects Behaviors are involved in survival and reproductivesuccess Many animals exhibit social behavior Sociobiology is social behavior applied to humansCopyright 2009 Pearson Education, Inc.

THE SCIENTIFIC STUDYOF BEHAVIORCopyright 2009 Pearson Education, Inc.

35.1 Behavioral ecologists ask both proximateand ultimate questions Behavioral ecologists study what animals do wheninteracting with their environment Behavior can be interpreted in terms of proximatecauses and ultimate causes with the environment– Proximate causes are immediate mechanisms for abehavior– Ultimate causes are the evolutionary explanations forbehaviorCopyright 2009 Pearson Education, Inc.

35.2 Fixed action patterns are innate behaviors Konrad Lorenz and Niko Tinbergen were among thefirst to demonstrate the importance of innatebehavior Innate behaviors are under strong genetic controland are performed in virtually the same way by allindividuals of a species– Many of Lorenz’s and Tinbergen’s studies wereconcerned with behavioral sequences called fixedaction patterns (FAPs)– A FAP is an unchangeable series of actions triggered bya specific stimulusCopyright 2009 Pearson Education, Inc.

35.2 Fixed action patterns are innate behaviors A sign stimulus triggers fixed action patterns– A sign stimulus is often a simple clue in an animal’senvironment The genetic programming underlying a FAP ensuresthat the activity is performed correctly withoutpractice– Examples are– Mating behaviors– Parent-offspring interactionsCopyright 2009 Pearson Education, Inc.

35.3 Behavior is the result of both genetic andenvironmental factors Animal behavior often involves a combination ofgenetic programming and environmental factors– Genetic programming includes innate behaviors– Environmental factors contribute to learning The nature-versus-nurture debate is not an either/orargument– It is about how both the genes and the environmentinteract to influence the development of phenotypictraitsCopyright 2009 Pearson Education, Inc.

Male emicalsdetected bythe male’ssense of smell.Male tapsfemale’s abdomenwith a foreleg.Tapping“Singing”Male extendsand vibrateswing, producinga courtshipsong.

35.3 Behavior is the result of both genetic andenvironmental factors Research on rats shows that interactions with themother change the pattern of gene expression inthe pups This experiment provides evidence that behavior isthe product of both genetic and environmentalfactors The interaction of genes and the environmentappears to determine most animal behaviorsCopyright 2009 Pearson Education, Inc.

High-interaction motherLow-interaction motherPups becomefearful adultsPups becomerelaxed adultsFemale pups becomehigh-interactionmothersFemale pups becomelow-interaction mothersCross-fosteringexperimentPups becomerelaxed adultsPups become fearful adults

LEARNINGCopyright 2009 Pearson Education, Inc.

35.4 Learning establishes specific links betweenexperience and behavior Learning is modification of behavior as a result ofspecific experiences Learning enables animals to change their behaviorsin response to changing environmental conditions There are various forms of learning– Simple behavioral change in response to a singlestimulus– Complex problem solving involving entirely newbehaviorsCopyright 2009 Pearson Education, Inc.

35.4 Learning establishes specific links betweenexperience and behavior Habituation is one of the simplest forms oflearning– An animal learns not to respond to a repeated stimulusthat conveys little or no information– In terms of ultimate causation, habituation mayincrease fitness by allowing an animal’s nervous systemto focus on stimuli that signal– Food– Mates– Real dangerCopyright 2009 Pearson Education, Inc.

35.5 Imprinting requires both innate behaviorand experience Imprinting is irreversible learning limited to asensitive period in an animal’s life– Imprinting enhances fitness by enabling rapid learningVideo: DucklingsCopyright 2009 Pearson Education, Inc.

Frequency(kilocycles/second)54321Normal bird (imprinted)54321Bird reared in isolation00.51.01.5Time (seconds)2.02.5

35.6 CONNECTION: Imprinting poses problemsand opportunities for conservation programs In attempting to save species that are at the edgeof extinction, biologists sometimes try to increasetheir numbers in captivity– Rearing animals in captivity is often successful– But without parents available as models for imprinting,the offspring may not learn appropriate behaviorsCopyright 2009 Pearson Education, Inc.

35.7 Animal movement may be a simple responseto stimuli or require spatial learning Kinesis is a random movement in response to astimulus– A kinesis may be merely starting or stopping, changingspeed, or turning more or less frequently Taxis is a response directed toward (positive taxis)or away from (negative taxis) a stimulus– Many stream fish, such as trout, exhibit positive taxis inthe current; they automatically swim or orient in anupstream directionCopyright 2009 Pearson Education, Inc.

Directionof rivercurrent

35.7 Animal movement may be a simple responseto stimuli or require spatial learning In spatial learning, animals establish memories oflandmarks in their environment Landmarks indicate the locations of food, nest sites,prospective mates, and potential hazards– The digger wasp uses landmarks to keep track of hernestsCopyright 2009 Pearson Education, Inc.

Nest1

Nest1Nest2No nest

Nest1NestNo nest2Nest3No nest

35.8 Movements of animals may depend oninternal maps An animal can move around its environment usinglandmarks alone– A cognitive map is an internal representation, or code,of the spatial relationships among objects in an animal’ssurroundingsCopyright 2009 Pearson Education, Inc.

PaperInk padFunnelshapedcage

PaperInk padFunnelshapedcage

35.8 Movements of animals may depend oninternal maps Movement in a directed way enables animals to– Avoid predators– Migrate to a more favorable environment– Obtain food– Find mates and nest sitesCopyright 2009 Pearson Education, Inc.

35.9 Animals may learn to associate a stimulus orbehavior with a response Associative learning is learning that a particularstimulus or response is linked to a reward orpunishment– Trial-and-error learning is an animal’s ability to learnto associate one of its own behaviors with a positive ornegative effectCopyright 2009 Pearson Education, Inc.

35.10 Social learning employs observation andimitation of others Social learning is learning by observing thebehavior of others– Many predators learn some of their basic hunting tacticsby observing and imitating their mothersCopyright 2009 Pearson Education, Inc.

35.11 Problem-solving behavior relies on cognition Cognition is the ability of an animal’s nervoussystem to perceive, store, process, and useinformation– Some animals have complex cognitive abilities thatinclude problem solving– Problem solving is the ability to apply past experienceto novel situations– Problem-solving behavior is highly developed in somemammals, especially dolphins and primatesVideo: Chimp Cracking NutCopyright 2009 Pearson Education, Inc.

SURVIVALAND REPRODUCTIVESUCCESSCopyright 2009 Pearson Education, Inc.

35.12 Behavioral ecologists use cost-benefitanalysis in studying foraging Animals are generally selective and efficient in theirfood choices– Some animals, such as crows, are feeding “generalists”– Other animals, such as koalas, are feeding “specialists” Natural selection seems to have shaped feedingbehavior to maximize energy gain and minimize theexpenditure of time and energy– This is the theory of optimal foragingCopyright 2009 Pearson Education, Inc.

35.12 Behavioral ecologists use cost-benefitanalysis in studying foraging The mechanism that enables an animal to findparticular foods efficiently is called a search imageCopyright 2009 Pearson Education, Inc.

Wagtail calorie intake/second handling time16141210056789Dung fly body length (mm)10

Percent of total5040Dung flies available(Total 460)30Dung flies eaten(Total 252)201005791068Dung fly body length (mm)

35.13 Communication is an essential element ofinteractions between animals Communication is an essential element ofinteractions between individuals– Communication is a signal stimulus transmitted by oneanimal to another animal– The more complex the social organization of a species,the more complex the signaling required to sustain itVideo: Bee PollinatingCopyright 2009 Pearson Education, Inc.

SunFood source30ºHive30º

35.13 Communication is an essential element ofinteractions between animals Animal communication can use the following typesof signaling– Sounds– Scents– Displays– TouchesCopyright 2009 Pearson Education, Inc.

35.14 Mating behavior often involves elaboratecourtship rituals Careful communication is an essential prerequisitefor mating– In many species, prospective mates must perform anelaborate courtship ritual– The ritual confirms that individuals are of the samespecies, of the opposite sexVideo: Albatross Courtship RitualVideo: Blue-footed Boobies Courtship RitualVideo: Giraffe Courtship RitualCopyright 2009 Pearson Education, Inc.

35.15 Mating behaviors and parental care enhancereproductive success Natural selection favors mating behaviors thatenhance reproductive success– The needs of the young are an important factor in theevolution of mating systems– Individuals with genes for favorable mating behaviorsreproduce more successfully and pass those genes onto the next generationCopyright 2009 Pearson Education, Inc.

35.16 CONNECTION: Chemical pollutants cancause abnormal behavior Scientists have linked observations of theseabnormal behaviors to endocrine disruptingchemicals– Like hormones, endocrine disruptors also affectbehavior– For example, some male fish defend territories to attractfemales during the breeding season; males have high levelsof androgens (male hormones) during this time– Researchers showed that the intensity of nest-guardingbehavior in certain male fish dropped after they wereexposed to pollutants that mimic the female hormoneestrogenCopyright 2009 Pearson Education, Inc.

Paper milldischargingwaste waterContaminatedsample sitesUncontaminatedsample sitesN2 kmPerdido Bay

FemaleMale

SOCIAL BEHAVIORAND SOCIOBIOLOGYCopyright 2009 Pearson Education, Inc.

35.17 Sociobiology places social behavior in anevolutionary context Biologists define social behavior as any kind ofinteraction between two or more animals, usually ofthe same species– Sociobiology applies evolutionary theory to the studyand interpretation of social behavior– Sociobiology explains how social behaviors are adaptiveand how they could have evolved by natural selectionCopyright 2009 Pearson Education, Inc.

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35.18 Territorial behavior parcels space andresources Many animals exhibit territorial behavior– A territory is an area, usually fixed in location, whichindividuals defend and from which other members ofthe same species are usually excluded– Territory behavior is a form of social behavior thatpartitions resourcesCopyright 2009 Pearson Education, Inc.