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PowerPoint Lectures Campbell Biology: Concepts & Connections, Eighth Edition REECE • TAYLOR • SIMON • DICKEY • HOGAN

Chapter 35

Lecture by Edward J. Zalisko

Behavioral Adaptations to the Environment


Introduction

• Meerkat Manor, which aired for four seasons on Animal Planet, starred a clan of small desert mammals belonging to the mongoose family.

• Viewers followed the meerkats’ exploits as they •  interacted with each other, •  defended themselves from rival clans, •  foraged for food, and •  faced death from illness and predators.


Introduction

• Researchers used observations of meerkats to test hypotheses about the evolution of

•  cooperative behavior, •  sexual selection, •  altruism, and •  other components of social behavior.

•  Fascinating behavioral adaptation are also displayed by birds, fish, and even invertebrates.

•  And not all behaviors are visible. For example, animal communication may employ sounds or scents.


Figure 35.0-1


Figure 35.0-2 Chapter 35: Big Ideas

The Scientific Study of Behavior

Survival and Reproductive Success

Social Behavior and Sociobiology

Learning


THE SCIENTIFIC STUDY OF BEHAVIOR


35.1 Behavioral ecologists ask both proximate and ultimate questions

• Behavior encompasses a wide range of activities. •  A behavior is an action carried out by muscles or

glands under the control of the nervous system in response to an environmental cue.

• Collectively, behavior is the sum of an animal’s responses to internal and external environmental cues.

• Behavioral ecology is the study of behavior in an evolutionary context.


Figure 35.1


35.1 Behavioral ecologists ask both proximate and ultimate questions

•  The questions investigated by behavioral ecologists fall into two broad categories.

1.  Proximate questions concern the immediate reason for the behavior. •  How is it triggered by stimuli (environmental cues that

cause a response)? •  What physiological or anatomical mechanisms play a role? •  What underlying genetic factors are at work? •  Proximate causes are the answers to such questions

about the immediate mechanism for behavior. 2.  Ultimate questions address why a particular behavior

occurs. Ultimate causes are the evolutionary explanations for behavior.


35.2 Fixed action patterns are innate behaviors

• Lorenz and Tinbergen were among the first to demonstrate the importance of innate behavior, behaviors that

•  are under strong genetic control and •  are performed in virtually the same way by all

individuals of a species.


35.2 Fixed action patterns are innate behaviors

• Many of Lorenz’s and Tinbergen’s studies were concerned with behavioral sequences called fixed action patterns (FAPs), an unchangeable series of actions triggered by a specific stimulus.

•  Once initiated, the sequence is performed in its entirety, regardless of any changes in circumstances.

•  Examples include •  reproductive behaviors and •  behaviors that must be done correctly the first time to

survive, such as a young chick hatched out on a cliff ledge starting to fly.


Figure 35.2a


Figure 35.2b


35.3 Behavior is the result of both genetic and environmental factors

• With the tools of molecular genetics, scientists have begun to investigate the roles of specific genes in behavior.

• Groundbreaking experiments with fruit flies have led to the discovery of genes that govern

•  learning, •  memory, •  internal clocks, and •  courtship and mating behaviors.

•  Some of the genes governing fruit fly behavior have counterparts in mice and even in humans.


Table 35.3



• Phenotype depends on •  the environment and •  genes.

• Many environmental factors, including diet and social interactions, can modify how genetic instructions are carried out.

•  In some animals, even an individual’s sex can be determined by the environment.



• Cross-fostering experiments are useful for studying environmental factors that affect behavior.

• Studies of rats reveal that behavioral changes can be passed to future generations, not through genes but through the social environment.

•  Interactions with the mother change the pattern of gene expression in the pups, thus affecting the development of parts of the neuroendocrine system that regulate the fight-or-flight response.


Figure 35.3a


Figure 35.3b

Cross-fostering experiment

Female pups become low-interaction mothers

Female pups become high-interaction mothers

Pups become relaxed adults

Low-interaction mother

Pups become fearful adults

High-interaction mother

Pups become fearful adults Pups become relaxed adults


LEARNING


35.4 Habituation is a simple type of learning

• Learning is modification of behavior as a result of specific experiences.

• Learning enables animals to change their behaviors in response to changing environmental conditions.

• There are various forms of learning, ranging from a simple behavioral change in response to a single stimulus to complex problem solving using entirely new behaviors.


Table 35.4


35.4 Habituation is a simple type of learning

• Habituation is one of the simplest forms of learning.

•  An animal learns not to respond to a repeated stimulus that conveys little or no information.

•  In terms of ultimate causation, habituation may increase fitness by allowing an animal’s nervous system to focus on stimuli that signal

•  food, •  mates, or •  real danger.


35.5 Imprinting requires both innate behavior and experience

•  Imprinting is •  generally irreversible learning and •  limited to a specific phase in an animal’s life called

a sensitive period. • Examples include

•  a young bird learning to identify its parents, •  newly hatched salmon imprinting on the complex

mixture of odors unique to their stream, and •  song development in birds.


Video: Ducklings


Figure 35.5a


Figure 35.5b

Normal bird (imprinted)

Bird reared in isolation

Freq

uenc

y (k

ilocy

cles

/sec

ond)

Time (seconds) 0 0.5 1.0 1.5 2.0 2.5

Adapted from P. Marler and M. Tamura, Culturally Transmitted Patterns of Vocal Behavior in Sparrows, Science 146: 3650, 1483–1486 (Dec. 11, 1964).

1 2 3 4 5

1 2 3 4 5


35.6 CONNECTION: Imprinting poses problems and opportunities for conservation programs •  In attempting to save species that are at the edge

of extinction, biologists sometimes try to increase their numbers in captivity.

• Artificial incubation in captivity is often successful. •  But without parents available as models for

imprinting, the offspring may not learn appropriate behaviors.

•  The effort to save the whooping crane is one example of a program that has successfully used surrogate parents, though they are a bit unusual.


35.6 CONNECTION: Imprinting poses problems and opportunities for conservation programs •  In 2001, Operation Migration applied its techniques

to whooping cranes. • When the chicks emerged from their shells, the first

thing they saw was a hand puppet, shaped and painted in the form of an adult whooping crane.

•  As the chicks grew, the same type of puppet guided them through exercise and training.


Figure 35.6a


35.6 CONNECTION: Imprinting poses problems and opportunities for conservation programs • The puppet was attached to a plane that rolled

along the ground, coaxing the chicks to follow it. • Eventually, the birds started following the plane on

short flights. • The young whooping cranes followed the plane

from their protected grounds in Wisconsin along a migratory route to Florida.

• The next spring, five of the eight young cranes retraced the route to Wisconsin on their own.


Figure 35.6b


35.7 VISUALIZING THE CONCEPT: Animal movement may be a response to stimuli or require spatial learning • Moving in a directed way enables animals to

•  avoid predators, • migrate to a more favorable environment, •  obtain food, and •  find mates and nest sites.


35.7 VISUALIZING THE CONCEPT: Animal movement may be a response to stimuli or require spatial learning • The simplest kinds of movement do not involve

learning. •  A random movement in response to a stimulus is

called a kinesis (plural, kineses). A kinesis may be merely

•  starting or stopping, •  changing speed, or •  turning more or less frequently.


Figure 35.7-0

KINESIS IN SOW BUGS

POSITIVE TAXIS IN SALMON

SPATIAL LEARNING IN DIGGER WASPS

Digger wasp

Nest No nest

A digger wasp near the entrance of its nest

A male sockeye salmon in breeding colors

Orientation of salmon

Dry area

A sow bug

Moist area

Direction of river current

Nest


Figure 35.7-1

KINESIS IN SOW BUGS

Dry area

A sow bug

Moist area

As a result of kinesis, random movement in response to a stimulus, sowbugs typically live in moist areas.

Sowbugs move randomly in response to dryness.

The random movement increases the chance of finding a moist area

After they reach a moist area, decreased activity tends to keep them there.


35.7 VISUALIZING THE CONCEPT: Animal movement may be a response to stimuli or require spatial learning

•  In contrast to kinesis, a taxis (plural, taxes) is a response directed

•  toward (positive taxis) or •  away from (negative taxis) a stimulus.


Figure 35.7-2

POSITIVE TAXIS IN SALMON A male sockeye salmon in breeding colors

Orientation of salmon Direction of river current

Salmon exhibit positive taxis in swimming upstream, toward the direction from which food is likely to come.


35.7 VISUALIZING THE CONCEPT: Animal movement may be a response to stimuli or require spatial learning •  In spatial learning, animals establish memories of

landmarks in their environment that indicate the locations of

•  food, •  nest sites, •  prospective mates, and •  potential hazards.

• Some animals use more sophisticated methods of navigating their environment.


Figure 35.7-3

SPATIAL LEARNING IN DIGGER WASPS

Digger wasp Nest No nest

A digger wasp near the entrance of its nest

Nest

A female digger wasp exhibits spatial learning when identifying new landmarks to locate her nests.

Before a mother wasp returns to one of her nests, a researcher places a circle of pinecones around it.

After the wasp returns and then leaves again, the researcher moves the pinecones a few feet away from the nest.

The wasp exhibits spatial learning by flying to the center

of the pinecone circle.


35.8 A variety of cues guide migratory movements

• Migration •  is the regular back-and-forth movement of animals

between two geographic areas, •  enables many species to access food resources

throughout the year, and •  allows them to breed or winter in areas that favor

survival.



• Gray whales • migrate annually between the coastlines of northern

Alaska and Baja California and •  navigate using

•  the coastline, spyhopping to identify visual reference points,

•  the topography of the ocean floor, •  cues from the temperature and chemistry of the

water, and •  magnetic sensing.


Figure 35.8a



• Magnetic cues feature prominently in sea turtle migrations.

• Loggerhead sea turtles hatching on beaches from North Carolina to Florida

•  enter the Atlantic Ocean to begin an incredible journey through thousands of miles of open ocean and

•  return to the North American coast.


Figure 35.8b



• Many birds migrate at night, navigating by the stars the way early sailors did.

•  In a series of classic experiments, researchers showed that one night-migrating bird, the indigo bunting, avoids the need for a timing mechanism by fixing on the North Star, the one bright star in northern skies that appears almost stationary.

• Birds that migrate during the daytime navigate by a combination of magnetic cues and visual cues such as landmarks and the position of the sun.


Figure 35.8c


35.9 Animals may learn to associate a stimulus or behavior with a response

• Associative learning is the ability to associate one environmental feature with another.

•  In one type of associative learning, an animal learns to link a particular stimulus to a particular outcome. For example, a dog may expect to go for a walk if the owner picks up the leash.

•  Trial-and-error learning is an animal’s ability to learn to associate one of its own behaviors with a positive or negative effect.

• Memory is the key to all associative learning.


Figure 35.9


35.10 Social learning employs observation and imitation of others

•  Social learning is learning by observing the behavior of others.

•  Many predators, including cats, coyotes, and wolves, seem to learn some of their basic hunting tactics by observing and imitating their mothers.

•  Alarm calls of vervet monkeys in Kenya provide an interesting example of how performance of a behavior can improve through social learning.

•  Vervets give distinct alarm calls when they see leopards, eagles, or snakes, all of which prey on vervets.

•  Upon hearing a particular alarm call, other vervets in the group behave in an appropriate way, depending on the type of threat.


Figure 35.10


35.11 Problem-solving behavior relies on cognition

• Cognition is the process carried out by an animal’s nervous system to perceive, store, integrate, and use information gathered by the senses.


35.11 Problem-solving behavior relies on cognition

• Some animals have complex cognitive abilities that include problem solving, the process of applying past experience to overcome obstacles in novel situations.

• Problem-solving behavior •  is highly developed in some mammals, especially

dolphins and primates, and •  has been observed in some bird species.


Video: Chimp Cracking Nut


Figure 35.11a


Figure 35.11b


SURVIVAL AND REPRODUCTIVE SUCCESS


35.12 Behavioral ecologists use cost–benefit analysis to study foraging

• Food-obtaining behavior, or foraging, includes •  eating and •  any mechanism an animal uses to search for,

recognize, and capture food. • Animals forage in a great many ways.

•  Some animals, such as crows, are feeding “generalists.”

• Other animals, such as koalas, are feeding “specialists.”



• The mechanism that enables an animal to find particular foods efficiently is called a search image.

• Animals with food choices face trade-offs involved in selection. There may be great variation in the amount of energy required to

•  locate, •  capture, •  subdue, and •  prepare prey for consumption.



• According to the predictions of optimal foraging theory, an animal’s feeding behavior should provide

• maximal energy gain with minimal energy expense and

• minimal risk of being eaten while foraging.



• A researcher tested part of this theory by studying insectivorous birds called wagtails.

•  In England, wagtails are commonly seen in cow pastures foraging for dung flies.

•  The researcher collected data on the time required for a wagtail to catch and consume dung flies of different sizes.


Figure 35.12a


Figure 35.12b



•  The smallest flies (5–6 mm in length) were easily handled but yielded few calories.

•  The caloric value of large flies (8–10 mm) was offset by the energy required to catch and consume them.

•  Thus, an optimal forager would be expected to choose medium-sized (7 mm) flies most often.

•  As Table 35.12 shows, the researcher found that wagtails did select medium-sized flies most often, even though they were not the most abundant size class.


Table 35.12


35.13 Communication is an essential element of interactions between animals

•  Interactions between animals depend on some form of signaling between the participating individuals.

•  In behavioral ecology, a signal is a stimulus transmitted by one animal to another animal.

• The sending of, reception of, and response to signals constitute animal communication, an essential element of interactions between individuals.


35.13 Communication is an essential element of interactions between animals

• Forms of communication vary considerably, and many animals use more than one type of signal simultaneously.

• Nocturnal mammals use odor and sound. • Diurnal birds use visual and auditory signals. •  Fish may use visual signals, electrical signals, and/

or sound. • Honeybees “dance” to signal to other bees the

location of a food source.


Video: Bee Pollinating


Figure 35.13a


Figure 35.13b

30°

30°

Sun

Hive

Food source


35.14 Mating behavior often involves elaborate courtship rituals

• Careful communication is an essential prerequisite for mating.

•  In many species, prospective mates must perform an elaborate courtship ritual.

•  The ritual confirms that individuals are of the same species, of the opposite sex, physically primed for mating, and not threats to each other.


Video: Albatross Courtship Ritual


Video: Blue-Footed Boobies Courtship Ritual


Video: Giraffe Courtship Ritual


Figure 35.14a


Figure 35.14b


Figure 35.14c


35.15 Mating systems and parental care enhance reproductive success

• Animal mating systems fall into three categories. 1.  Promiscuous systems have no

•  strong pair-bonds or •  lasting relationships between males and females.

2.  Monogamous systems have •  one male and one female and •  shared parental care.

3.  Polygamous systems •  have one individual of one sex mating with several of

the other and •  usually consist of one male and many females.


35.15 Mating systems and parental care enhance reproductive success

• The needs of offspring and certainty of paternity help explain differences in

• mating systems and •  parental care by males.


Figure 35.15a


Figure 35.15b


35.16 CONNECTION: Chemical pollutants can cause abnormal behavior

• Endocrine disruptors •  are a diverse group of substances that affect the

vertebrate endocrine system by mimicking a hormone or by enhancing or inhibiting hormone activity and

•  enter ecosystems from a variety of sources, including

•  discharge from paper and lumber mills and factory wastes such as dioxin and PCBs and

•  agriculture, including DDT and other pesticides.



• Endocrine-disrupting chemicals have been linked to

•  fish that are lackadaisical about territorial defense, •  salamanders that ignore mating cues, •  birds that exhibit sloppy nest-building techniques, • mice that take inexplicable risks, and •  reduced nest-guarding behavior in male

sticklebacks.


Figure 35.16a



• Another series of studies showed that in female mosquitofish,

•  anatomy was masculinized by endocrine disruptors, •  females exposed to pollutants discharged from a

paper mill developed the fin modification that males use to transfer sperm to females, and

• masculinized females also behaved like males, waving the fin back and forth in front of females in the typical courtship behavior.


Figure 35.16b

Female

Male


SOCIAL BEHAVIOR AND SOCIOBIOLOGY


35.17 Sociobiology places social behavior in an evolutionary context

• Biologists define social behavior as any kind of interaction between two or more animals, usually of the same species.

• Sociobiology applies evolutionary theory to the study and interpretation of social behavior to explain how social behaviors

•  are adaptive and •  could have evolved by natural selection.


35.18 Territorial behavior parcels out space and resources

• Many animals exhibit territorial behavior. •  A territory is an area, usually fixed in location, that

one or more individuals defend and from which other members of the same species are usually excluded.

•  Territories are usually used for •  feeding, •  mating, •  rearing young, or •  a combination of these activities.


Figure 35.18a


35.18 Territorial behavior parcels out space and resources

•  Individuals that have established a territory usually proclaim their territorial rights continually. Examples include

•  the songs of bird, •  the noisy bellowing of sea lions, •  the chattering of squirrels, and •  scent markers used to signal a male coyote’s

territorial boundaries.


Figure 35.18b


35.19 Agonistic behavior often resolves confrontations between competitors

•  In many species, conflicts that arise over limited resources, such as food, mates, or territories, are settled by agonistic behavior, which

•  is social behavior that consists of threats, rituals, and sometimes combat that determines which competitor gains access to a resource and

•  can directly affect an individual’s evolutionary fitness.


Video: Chimp Agonistic Behavior


Video: Snake Ritual Wrestling


Video: Wolves Agonistic Behavior


Figure 35.19


35.20 Dominance hierarchies are maintained by agonistic behavior

• Many animals live in social groups maintained by agonistic behaviors.

• Dominance hierarchy is the ranking of individuals based on social interactions. Examples include

•  pecking order in chickens and •  hierarchies among the females within a wolf pack.


Figure 35.20


35.21 EVOLUTION CONNECTION: Altruistic acts can often be explained by the concept of inclusive fitness • Many social behaviors are selfish because natural

selection favors behaviors that maximize an individual’s

•  survival and •  reproductive success.

• Altruism is defined as behavior that reduces an individual’s fitness while increasing the fitness of others in the population.


35.21 EVOLUTION CONNECTION: Altruistic acts can often be explained by the concept of inclusive fitness • The concept of inclusive fitness describes an

individual’s success at perpetuating its genes by •  producing its own offspring and •  helping close relatives, who likely share many of

those genes, to produce offspring. • Natural selection favoring altruistic behavior that

benefits relatives is called kin selection. Thus, genes for altruism may be propagated if individuals that benefit from altruistic acts are themselves carrying those genes.


Figure 35.21a


35.21 EVOLUTION CONNECTION: Altruistic acts can often be explained by the concept of inclusive fitness • A classic study of Belding’s ground squirrels, which

live in regions of the western United States, provided empirical support for kin selection.


Figure 35.21b

Data from P. W. Sherman, Nepotism and the evolution of alarm calls, Science 197: 1246–1253 (1977).

80

60

40

20

0 Daughters or

granddaughters No

relatives Mothers or

sisters No

relatives Relatives living nearby

Perc

enta

ge o

f tim

es fe

mal

es

give

ala

rm c

all


35.22 SCIENTIFIC THINKING: Jane Goodall revolutionized our understanding of chimpanzee behavior •  In 1960, paleoanthropologist Louis Leakey, who

discovered Homo habilis and its stone tools, thought that studying the behavior of our closest relatives might provide insight into the behavior of early humans.

• Leakey hired Jane Goodall, who had no scientific background, to observe chimpanzees in the wild.


35.22 SCIENTIFIC THINKING: Jane Goodall revolutionized our understanding of chimpanzee behavior • Goodall documented the social organization and

behavior of chimpanzees through countless hours of carefully recorded observations in an area that was later designated the Gombe Stream Research Center, near Lake Tanganyika in Africa.


Figure 35.22a


35.22 SCIENTIFIC THINKING: Jane Goodall revolutionized our understanding of chimpanzee behavior • Her research documented

•  chimpanzees making and using tools, •  chimpanzees eating meat as well as plants, •  close bonds between chimpanzee mothers and

their offspring, and •  daily foraging activities undertaken by small groups

consisting of a mother and her offspring, sometimes with one or two males.


Figure 35.22b


35.22 SCIENTIFIC THINKING: Jane Goodall revolutionized our understanding of chimpanzee behavior •  Jane Goodall’s pioneering research demonstrates

the importance of descriptive, or qualitative, data in science.

• Her career is also a shining example of another aspect of science: communication. She extended her audience to include the general public through

•  her many books, •  lecture tours, and •  television appearances.


35.23 Human behavior is the result of both genetic and environmental factors

• Variations in behavioral traits such as personality, temperament, talents, and intellectual abilities make each person a unique individual.

• What are the roles of nature (genes) and nurture (environment) in shaping these behaviors?



• Twins provide a natural laboratory for investigating the origins of complex behavioral traits.

• Twin studies compare identical twins, who have the same DNA sequence and are raised in the same environment, with fraternal twins, who share an environment but only half of their DNA sequence.


Figure 35.23a


Figure 35.23b



• Results from twin studies consistently show that for complex behavioral traits such as general intelligence and personality characteristics, genetic differences account for roughly half the variation among individuals.

• Genes do not dictate behavior but, instead, cause tendencies to react to the environment in a certain way.



• The mechanisms and underlying genetics of behavior are proximate causes.

• Sociobiology centers on the idea that social behavior evolves, like anatomical traits, as an expression of genes that have been perpetuated by natural selection.

•  It is unlikely that most human behavior is directly programmed by our genome.


You should now be able to

1.  Define and distinguish between the proximate and ultimate causes of behavior.

2.  Describe the adaptive advantage of innate behaviors.

3.  Describe the respective roles of genetics and the environment in shaping behavior.

4.  Define the seven types of learning and note the adaptive advantages and examples of each.

5.  Define search images and optimal foraging, providing examples of each.



6.  Compare the types of signals used by nocturnal and diurnal animals.

7.  Explain how courtship rituals are adaptive. 8.  Compare monogamous and polygamous

relationships. 9.  Explain how endocrine disruptors may be

introduced into the environment and describe the consequences of this pollution.

10.  Define social behavior and sociobiology, providing examples of each.



11.  Define a territory and describe the ways in which territories are used, identified, and defended.

12.  Define agonistic behavior and explain how agonistic behavior is adaptive.

13.  Explain how dominance hierarchies are maintained and identify their adaptive value.

14.  Define altruism and kin selection and describe examples of each.

15.  Explain how genes and environmental factors contribute to human social behavior.


Figure 35.UN01


Figure 35.UN02

is a product of both

environment (a)

(c)

(b)

Animal behavior

most important in both influence

examples are

example is learning

Innate behavior

occurs during

(d) (e) (f)

uses may be includes

observation and imitation trial and error landmarks sensitive

period


Figure 35.UN03

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