Transcript Behavior ecologyx

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Chemistry of Life ………………………………7%
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Prokaryotic and Eudaryotic cells
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Cellular Energetics…………………………….8%
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II. Heredity and Evolution …………………………………….. 25%
Heredity ………………………………………..8%
Meiosis and gametogenesis
Eukaryotic chromosomes
Inheritance patterns
Molecular Genetics ………………………… 9%
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Evolutionary Biology ………………………… 8%
Early evolution of life
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Mechanisms of evolution
III. Organisms and Populations……………………………… 50%
Diversity of Organisms ……………………… 8%
Evolutionary patterns
Survey of the diversity of life
Phylogenetic classification
Evolutionary relationships
Structure and Function of Plants and Animals..32%
Reproduction, growth, and development
Structural, physiological, and behavioral
adaptation. Response to the environment
Ecology …………………………………………10%
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CHAPTER 51
BEHAVIORAL ECOLOGY
Section A: Introduction to Behavior and Behavioral
Ecology
1. What is behavior?
2. Behavior has both proximate and ultimate causes
3. Behavior results from both genes and
environmental factors
4. Innate behavior is developmentally fixed
5. Classical ethology presaged an evolutionary
approach to behavioral biology
6. Behavioral ecology emphasizes evolutionary
hypotheses
1. What is Behavior?
Behavior is what an animal does
and how it does it.
• (1) What are some examples of behavior in
animals that you have observed this
summer?
2. Behavioral has both
proximate and ultimate causes
• Proximate questions are mechanistic,
concerned with the environmental stimuli that
trigger a behavior, as well as the genetic and
physiological mechanisms underlying a
behavioral act- the “how”.
• Ultimate questions address the evolutionary
significance for a behavior and why natural
selection favors this behavior.
For an example, many animals
breed in the spring or early
summer.
• (2) What is the probable proximate cause of this
behavior? / What is the probable ultimate cause
of this behavior?
• These two levels of causation are related.
– For example, many animals breed during the
spring and summer because of the warmth of
the seasons.
– The abundant food supply may increase the
chances of offspring surviving.
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
• Ultimate, or “why,” questions about
behavior
– Address the evolutionary significance of a
behavior
3. Behavior results from both genes
and environmental factors
• In biology, the nature-versus-nurture issue is
not about whether genes or environment
influence behavior, but that both are
involved.
• Are some behaviors genetically
“programmed”?
4. Innate behavior is
developmentally fixed
• These behaviors are due to genetic
programming.
• The range of environmental differences
among individuals does not appear to alter
the behavior.
• Case studies have shown this.
• Want to know more?- Human genome
findings for genes related to specific
behaviors
One way to find out if a behavior has a genetic basis
would be to show that behavioral differences exist prior
to any learning opportunity.
For example
• Most newly hatched birds do not shove nearby eggs
out of the nest.
• But consider the African cuckoo. When a nest of
another bird species is left unattended, the female
cuckoo quickly swoops down and lays an egg in the
nest.
• Even before the newly hatched cuckoo chick opens its
eyes, it shoves the other eggs out of the nest.
• Surprisingly, the unsuspecting host bird will go on
feeding the baby cuckoo, even when the cuckoo has
grown much larger than the host!
Why would this behavior be instinctual (gene-based)?
5. Classical ethology presaged an
evolutionary approach to behavioral
biology
• Ethology is the study of how animals
behave in their natural habitat.
– Karl von Frisch, Konrad Lorenz, and Niko
Tinbergen are three individuals who were
foremost in the initial stages of this field.
Fixed action pattern (FAP)
• A sequence of behavioral acts that is
essentially unchangeable and usually carried to
completion once initiated.
• The FAP is triggered by an external sensory stimulus known as
a sign stimulus (stimuli are usually obvious).
• The FAP usually occurs in a series of actions the same way
every time.
• Many animals tend to use a relatively small subset of the
sensory information available to them and behave
stereotypically.
Example
• In male stickleback fish, the stimulus for
attack behavior
– Is the red underside of an intruder
(a) A male three-spined stickleback fish shows its red underside.
• When presented with unrealistic models
– As long as some red is present, the attack
behavior occurs
(b) The realistic model at the top, without a red underside, produces no aggressive response in a male three-spined
stickleback fish. Theother models, with red undersides, produce strong responses.
\
• Proximate and ultimate causes for the FAP
attack behavior in male stickleback fish
BEHAVIOR: A male stickleback fish attacks other male sticklebacks that invade its nesting territory.
PROXIMATE CAUSE: The red belly of the intruding male acts as a sign stimulus
that releases aggression in a male stickleback.
ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreases
the chance that eggs laid in his nesting territory will be fertilized by another male.
Lorenz' Hydraulic Model of motivation
Flyfishing for trout may be an example of presenting a sign
stimulus to an animal in order to elicit a Fixed Action
Pattern.
• The artificial flies used by anglers resemble the living insect in
some important aspects -e.g. size, shape and color.
• But as every flyfisherman knows a particular pattern of fly that
works on one occasion may not catch a trout the next time it is
presented. The effectiveness of the stimulus is affected by:
• the trout's hunger - i.e. its motivation to feed
• some artificial flies are more effective than others, particularly
at certain times of the year presumably because the trout has
expectations based on which insects are hatching.
• This example shows the importance of internal motivational
factors in controlling behavior.
6. Behavioral ecology emphasizes
evolutionary hypotheses
• Behavioral ecology is the research field that
views behavior as an evolutionary adaptation
to the natural ecological conditions of
animals.
• We expect animals to behave in ways that
maximize their fitness (this idea is valid only
if genes influence behavior).
• Songbird
repertoires
provide us with
examples.
• Why has natural
selection favored
a multi-song
behavior?
Fig. 51.5
• It may be advantageous for males attracting
females.
Fig. 51.6
CHAPTER 51.3
BEHAVIORAL ECOLOGY
Section B: Learning
1. Learning is experienced-based modification of
behavior
2. Imprinting is learning limited to a sensitive
period
3. Bird song provides a model system for
understanding the development of behavior
4. Many animals can learn to associate one
stimulus with another
5. Practice and exercise may explain the ultimate
bases of play
1. Learning is experience-based
modification of behavior
• Learning is the modification
of behavior resulting from
specific experiences.
– The alarm calls of vervet
monkeys provide an example of how
animals improve their performance
of behavior.
– Vervet monkeys have at least three distinct
alarm calls for three different predators:
leopards, eagles and snakes. The alarm
signals lead to distinct behavioral
responses.
– When Seyfarth and colleagues (1980)
played tape recordings of alarm calls to a
group of free-ranging (non-captive) vervets,
the leopard-type alarm call made the
monkeys run into trees. The eagle-type
alarm call made them look up at the sky.
The snake-type alarm call made them look
down to the ground. Video: animal planet
Learning versus maturation.
• Maturation is the situation in which a
behavior may improve because of ongoing
developmental changes in neuromuscular
systems, for example, flight in birds.
– As a bird continues to develop its muscles and
nervous system, it is able to fly.
– It is not true learning.
• Habituation.
– This involves a loss of responsiveness to
unimportant stimuli or stimuli that do not
provide appropriate feedback.
• For example, some animals stop responding
to warning signals if signals are not followed
by a predator attack (the “cry-wolf” effect).
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
2. Imprinting is learning limited
to a sensitive period
• Imprinting is the recognition, response, and
attachment of young to a particular adult or
object.
• Konrad Lorenz experimented with geese that
spent the first hours of their life with him and
after time responded to him as their “parent.”
– Lorenz isolated geese after hatching and
found that they could no longer imprint on
anything.
• What is innate
in these birds is the
ability to respond
to a parent figure;
while the outside
world provides
the imprinting
stimulus.
• The sensitive period
is a limited phase in
an individual animal’s
development when learning
particular behaviors can take place
Fig. 51.9
3. Bird song provides a model system for
understanding the development of behavior
• Some songbirds have a sensitive period for
developing their songs.
– Individuals reared in silence performed abnormal
songs, but if recordings of the proper songs were
played early in the life of the bird, normal songs
developed.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 51.10a
• Canaries exhibit open-ended learning
where they add new syllables to their song
as the get older.
• What large mammal does this?
Fig. 51.10b
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
4. Many animals can learn to associate
one stimulus with another
• Associative learning is the ability of many
animals to learn to associate one stimulus
with another.
– Classical conditioning is a type of associative
learning.
– Pavlov’s dog is a good example.
• Ivan Pavlov exposed dogs to a bell ringing and at
the same time sprayed their mouths with
powdered meat, causing them to salivate.
• Soon, the dogs would salivate after hearing the
bell but not getting any powdered meat.
• Pavlov’s dog game
• Operant conditioning.
– This is called trial-and-error learning - an
animal learns to associate one of its own
behaviors with a reward or a punishment.
Fig. 51.11
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
5. Practice and exercise may
explain the ultimate bases of play
• Play as a behavior has no apparent external
goal, but may facilitate social development or
practice of certain behaviors and provide
exercise.
Fig. 51.12
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
CHAPTER 51
BEHAVIORAL ECOLOGY
Section C: Animal Cognition
1. The study of cognition connects nervous
system functioning with behavior
2. Animals use various cognitive mechanisms
during movement through space
3. The study of consciousness poses a unique
challenge for scientists
Introduction
• Animal cognition is an animal’s ability to be
aware of and make judgments about its
environment.
1. The study of cognition connects
nervous system function with behavior
• Cognition is the ability of an
animal’s nervous system to
perceive, store, process,
and use information
gathered by sensory
receptors.
• National Geographic Clip
Fig. 51.13
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
2. Animals use various cognitive mechanisms
during movement through space
• Kinesis and taxis.
• These are the simplest mechanisms of
movement.
• Kinesis is a change in activity rate in response to a
stimulus.
• Taxis is an automatic, oriented movement to or away
from a stimulus.
– For example, phototaxis, chemotaxis, and geotaxis.
• Many stream fish exhibit positive rheotaxis
– Where they automatically swim in an
upstream direction
Direction
of river
current
(b) Positive rheotaxis keeps trout facing into the current, the direction
from which most food comes.
Figure 51.7b
Kinesis or taxis?
Moist site
under leaf
Dry open
area
Figure 51.7a
Kinesis or taxis?
Kinesis or taxis?
• Use of landmarks within a familiar area.
– Some organisms move in response to a
recognized object or environmental cue,
the object is the landmark.
• Cognitive maps.
– Some animals form cognitive maps
(internal codes of spatial relationships of
objects in the environment).
EXPERIMENT
A female digger wasp excavates and cares for four
or five separate underground nests, flying to each nest daily with food
for the single larva in the nest. To test his hypothesis that the wasp
uses visual landmarks to locate the nests, Niko Tinbergen marked one
nest with a ring of pinecones.
• Further study
Nest
RESULTS
When the wasp returned, she flew to the center of
the pinecone circle instead of to the nearby nest. Repeating the
experiment with many wasps, Tinbergen obtained the same results.
No Nest
Nest
CONCLUSION
The experiment supported the hypothesis
that digger wasps use landmarks to keep track of their nests.
• Migration Behavior.
– Migration is the
regular movement
of animals over
relatively long
distances.
– Which animal
migrates the furthest?
– Piloting: an animal
moves from one
familiar landmark
to another until it
reaches its
destination.
Fig. 51.15
• Orientation: animals can detect directions and
travel in particular paths until reaching
destination.
– Navigation is the most complex, and involves
determining one’s present location relative to
other locations in
addition to detecting
compass directions.
– Cues for these
behaviors include
the earth’s magnetic
field, the sun, and
the stars.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 51.15
Leatherback sea turtle migration
http://www.youtube.com/watch?v=ssIY1HDkH0o
3. The study of consciousness poses a
unique challenge for scientists
• Besides humans, are animals aware of themselves?
• Some would
argue that
certain behaviors
are a result of
conscious
processing.
• In an experiment, an Asian elephant named Happy repeatedly
touched her trunk to a white X painted on her forehead while
looking in a mirror. This suggests that the animal recognized
herself in the reflection, scientists say, making the elephant one
of the few animals known to be capable of self-recognition.
CHAPTER 51
BEHAVIORAL ECOLOGY
Section D: Social Behavior and Sociobiology
1. Sociobiology places social behavior in an
evolutionary context
2. Competitive social behaviors often represent
contests for resources
3. Natural selection favors mating behavior that
maximizes the quantity or quality of mating
partners
1. Sociobiology places social behavior
in an evolutionary context
• Social behavior is any kind of interaction
between two or more animals, usually of the
same species.
By the way, what is the most
social of all species on planet
Earth?
High
School
Students
2. Competitive social behaviors often
represent contests for resources
• Sometimes
cooperation
occurs.
Fig. 51.18
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
• Agonistic behavior is a contest involving threats.
– Submissive behavior.
– Ritual: the use of symbolic activity.
– Generally, no harm is done.
– (wolf video clip)
Fig. 51.19
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
• Reconciliation behavior often happens
between conflicting individuals.
Fig. 51.20
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
• Dominance hierarchies involve a ranking
of individuals in a group (a “pecking order”).
– Alpha, beta rankings exist.
• The alpha organisms control the behavior of
others.
• Pecking order video-
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
• Territoriality is behavior where an individual
defends a particular area, called the
territory.
– Territories are typically used for feeding,
mating, and rearing young and are fixed in
location.
Fig. 51.21
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
– Drawbacks are that territoriality uses a
great deal of an individual’s energy.
• In addition, an individual might be defending a
territory and die or miss a reproductive
opportunity.
– Spraying behavior is where an individual
marks its territory.
Fig. 51.22
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
3. Natural selection favors mating
behavior that maximizes the quantity
or quality of mating partners
• Courtship behavior consists of patterns that
lead to mating and consists of a series of
displays and movements by the male or
female.
• (Planet Earth Clip)
• David Attenborough: bowerbird
Parental investment refers to the time and
resources expended for raising of offspring.
• It is generally lower in males because they are capable of
producing more gametes (which are also smaller),
therefore making each one less valuable.
• Females usually invest more time into parenting because
they make fewer, larger gametes, a process which is
energetically more expensive, thus making each gamete
more valuable.
• In terms of mate choice, females are usually more
discriminating in terms of the males with whom they
choose to mate.
– Females look for more fit males (i.e., better genes), the ultimate cause of
the choice.
• Mating systems differ among species.
– Promiscuous: no strong bond pairs
between males and females.
– Monogamous: one male mating with one
female.
– Polygamous: an individual of one sex
mating with several of the other sex.
• Polygyny is a specific example of polygamy,
where a single male mates with many females.
• Polyandry occurs in some species where one
female mates with several males.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
No other species
comes close to matching the social learning and cultural
transmission that occurs among humans.
Sociobiology connects evolutionary theory to human culture
• E.O. Wilson's most notable field of research, however, was in
sociobiology. In his 1975 book entitled Sociobiology: The New
Synthesis, Wilson observed behavior in insects which suggested
that one individual insect is inclined to help its colony, even at
possible cost to itself; that is to say the welfare of the entire
colony was far more important than that of the individual. This
research represented great strides in the field of biology as no
one had ever been able to substantiate that acts of altruism,
kindness and labor specialization were fundamental among
various species.
Examples:
• A great deal of controversy arose when, near the end of
Sociobiology, Wilson hypothesized that his research with insects
could be linked to animal and human behavior. He proposed
that certain specific behaviors are, in fact, genetically
determined. This prompted a huge revolt, people did not want to
believe that their actions were controlled by anything but destiny
or free will; genetics could not enter the picture.
http://plato.stanford.edu/entries/sociobiology/
Extra credit• 1 page summary of this NOVA production
on E.O. Wilson
• http://www.tv.com/video/10400901/nova-lord-of-the-ants