Download Chapter 35

Chapter 35
Behavioral Adaptations to the
Environment
PowerPoint Lectures for
Biology: Concepts and Connections, Fifth Edition
– Campbell, Reece, Taylor, and Simon
Lectures by Chris Romero
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Leaping Herds of Herbivores
• Impalas of the African savanna are one of the
most successful species, despite heavy
pressure from predators
• Behavior is the key to the impala's success
• The study of animal behavior is essential to
understanding animal evolution and ecological
interactions
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
THE SCIENTIFIC STUDY OF BEHAVIOR
35.1 Behavioral ecologists ask both proximate
and ultimate questions
• Behavior: everything an animal does and how
it does it
– Includes unobservable activities such as
learning
• Early workers in the field of behavioral biology
– Karl von Frisch studied honeybee behavior
– Konrad Lorenz compared behavior of
animals in response to different stimuli
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– Niko Tinbergen pioneered behavioral
ecology, the study of behavior in an
evolutionary context
• Proximate questions focus on immediate
causes of a behavior
• Ultimate questions focus on the evolutionary
cause of a behavior
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35.2 Early behaviorists used experiments to
study fixed action patterns
• Innate behavior: behavior performed the same
way by all members of a species
– Under strong genetic control but improves
with experience
• Fixed action patterns: innate unchangeable
behavioral sequences
– Triggered by a sign stimulus
– Advantageous when behaviors must be
performed without time for learning
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35.3 Behavior is the result of both genes and
environmental factors
• Phenotypic traits-including behavior-are the
result of both genetic and environmental
influences
• Studies of complex mating and parenting
behaviors in prairie voles
– Differences in oxytocin and vasopressin
receptors in montane and prairie voles
– Transgenic experiments with mice
• A single gene may control much of
prairie vole behavior
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– Cross-fostering experiments
• Experience during development can
change later behavior
– Conclusion: strong evidence that vole
behaviors are the product of both genes
and environment
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LEARNING
35.4 Learning ranges from simple behavioral
changes to complex problem solving
• Learning: a change in behavior resulting from
experience
– Enables animals to respond to
environmental conditions
• Habituation: learning not to respond to a
repeated uninformative stimulus
– May increase fitness by allowing nervous
system to focus on important stimuli
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35.5 Imprinting is learning that involves innate
behavior and experience
• Imprinting: irreversible learned behavior
– Limited to a sensitive period
– Demonstrated in classic experiments by
Konrad Lorenz
– Important in formation of bonds between
parents and young
– Functions in salmon finding home stream
– Plays a role in song development for many
birds
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Video: Ducklings
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CONNECTION
35.6 Imprinting poses problems and opportunities
for conservation programs
• Endangered cranes imprinted on foster
parents would not breed with their own species
• Operation Migration
– Chicks bonded with planes used as
surrogate mothers
– Young birds learned migration routes
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35.7 Animal movement may be a simple
response to stimuli or involve spatial learning
• Kinesis: random movement in response to a
stimulus
• Taxis: more or less automatic movement
directed toward or away from a stimulus
• Spatial learning: more complex than kinesis or
taxis
– Involves using landmarks to move through
the environment
– Example: Tinbergen wasp experiment
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LE 35-7a
Direction
of river
current
LE 35-7b
Nest
No nest
Nest
Nest
No nest
35.8 Movements of animals may depend on
internal maps
• Cognitive map: internal representation of
spatial relationships among objects in an
animal's surroundings
• Migration: regular back-and-forth movement
between two geographic areas
– Animals may use sun, stars, landmarks, or
innate responses to environmental cues to
navigate
• Example: indigo buntings' star map
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LE 35-8
Paper
Ink pad
Funnelshaped
cage
35.9 Animals may learn to associate a stimulus
or behavior with a response
• Associative learning
– Animal learns that a particular stimulus or
response is linked to a reward or
punishment
• Trial-and-error learning
– Animal learns to associate one of its own
behavioral acts with a positive or negative
effect
– Animal repeats or avoids the response
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35.10 Social learning involves observation and
imitation of others
• Social learning: learning by observing the
behavior of others
– Example: vervet monkey alarm calls
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35.11 Problem-solving behavior relies on
cognition
• Cognition: ability of an animal's nervous
system to perceive, store, process, and use
information gathered by sensory receptors
• Problem solving: ability to apply past
experience to novel situations
– Involves complex cognitive processes
– Highly developed in some mammals
– Observed in some bird species
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Video: Chimp Cracking Nut
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FORAGING AND MATING BEHAVIORS
35.12 Behavioral ecologists use cost-benefit
analysis in studying foraging
• Foraging: food-obtaining behavior
– Includes recognizing, searching for,
capturing, and eating food items
• Animals forage in many ways
– Generalists eat all or most available foods
(example: gulls)
– Specialists eat only specific things
(example: koalas)
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• Search image: mechanism that enables finding
a particular food efficiently
• Optimal foraging theory: feeding behavior
should provide maximal energy gain with
minimal energy expense and risk
– Occurs among many species when prey is
plentiful
– May be improved by group behavior
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35.13 Mating behaviors enhance reproductive
success
• Several mating systems are found among
animals
– Promiscuous: no strong pair-bonds or
lasting relationships between males and
females
– Monogamous: one male with one female
– Polygamous: individual of one sex mating
with several of the other sex
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• Needs of offspring and certainty of paternity
help explain differences in mating systems and
parental care
– Needy young generally have monogamous
parents (example: many birds)
– Mating and birth separated by time often
lead to parental care by males (example:
fish)
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35.14 Mating behavior often involves elaborate
courtship rituals
• In many species, courtship rituals confirm that
individuals are
– Of the same species
– Of the opposite sex
– Are physically primed for mating
– Are not a threat
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• Courtship rituals are a group activity in some
species
– Members of one or both sexes choose
mates from a group of candidates
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Video: Albatross Courtship Ritual
Video: Blue-footed Boobies Courtship Ritual
Video: Giraffe Courtship Ritual
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SOCIAL BEHAVIOR AND SOCIOBIOLOGY
35.15 Sociobiology places social behavior in an
evolutionary context
• Social behavior: any interaction between two
or more animals
– Examples: courtship, aggression,
cooperation
• Sociobiology applies evolutionary theory to
social behaviors
– How they are adaptive
– How they could have evolved by natural
selection
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35.16 Territorial behavior parcels space and
resources
• A territory is an area that is
– Usually fixed in location
– Inhabited by an individual
– Defended from occupancy by other
individuals of the same species
• Territory size varies with species, function of
the territory, and resources available
• Territories are used for feeding, mating, and/or
rearing young
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35.17 Rituals involving agonistic behavior often
resolve confrontations between competitors
• Agonistic behavior settles disputes over
resources
– Includes threat, rituals, and sometimes
combat
– Can directly affect an individual's
evolutionary fitness
• Natural selection has favored ritualized rather
than violent combat
Video: Snake Ritual Wrestling
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
35.18 Dominance hierarchies are maintained by
agonistic behavior
• Dominance hierarchy: a ranking of individuals
based on social interaction
– Partitions resources among members of a
social group
– Once established, is fixed for a fairly long
time
– Common, especially in vertebrate
populations
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Video: Wolves Agonistic Behavior
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TALKING ABOUT SCIENCE
35.19 Behavioral biologist Jane Goodall
discusses dominance hierarchies and
reconciliation behavior in chimpanzees
• Both male and female chimpanzees have
dominance hierarchies
• Social primates spend substantial time in
reconciliation behavior
– Contributes to group stability
Video: Chimp Agonistic Behavior
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35.20 Social behavior requires communication
between animals
• Social behavior requires some form of
signaling between participating animals
– Signal: a behavior that causes a change in
behavior in another animal
– Communication: sending and reception of,
and response to, signals
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• Types of signals vary
– Terrestrial animals
• Many nocturnal mammals use odor and
sound
• Diurnal animals tend to use visual and
sound
– Aquatic animals
• Visual, electrical, chemical signals
– Complexity of signals echoes social
complexity
• Example: honeybees
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
35.21 Altruistic acts can often be explained by
the concept of inclusive fitness
• Many social behaviors are selfish
– Maximize individual fitness
• Altruism is behavior that reduces an
individual's fitness while increasing the fitness
of others in the population
– At first seems maladaptive
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– Can usually be explained by inclusive
fitness and kin selection
• An animal can propagate its own genes by
helping relatives reproduce
– In reciprocal altruism unrelated individuals
do favors that may later be repaid
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
CONNECTION
35.22 Both genes and culture contribute to
human social behavior
• Human social behaviors reflect a complex mix
of innate and learned influences
– Culture: a system of information transfer
through social learning or teaching
• Influences behavior of individuals in a
population
– Example: Studies of human partner choice
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TALKING ABOUT SCIENCE
35.23 Edward O. Wilson promoted the field of
sociobiology and is a leading conservation
activist
• Dr. E. O. Wilson's 1975 book Sociobiology:
The New Synthesis promotes the idea that
social behavior is genetically based
• The perspective of evolutionary biology has a
new importance for society
– The value of biodiversity and the humancreated biodiversity crisis
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings