Communication cooperation and conflict in the animal world Lectures by Mark Manteuffel St Louis Community College Learning Objectives Be able to explain the following Behaviors are traits that can evolve ID: 534284
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Chapter 9: Evolution and Behavior
Communication, cooperation, and conflict in the animal world
Lectures by Mark Manteuffel, St. Louis Community CollegeSlide2
Learning Objectives
Be able to explain the following:
Behaviors are traits that can evolveCooperation, selfishness, and altruism can be better understood with an evolutionary approachSexual conflict can result from disparities in reproductive investment by males and females
Communication
and the design of
signals evolveSlide3
Behaviors
are traits that can evolve.Slide4
9.1 Behavior has adaptive value, just like other traits
Animals should maximize energy consumed and minimize energy usedSlide5
Humans like to eat foods high in fat and sugar.Slide6Slide7Slide8
Why do species have taste preferences?
Feeding choices directly influence fitness.
Living and reproducing require energy.Maximal extraction of energy and acquisition of essential nutrientsNatural selection can shape feeding behavior.Slide9
Behavior
Behavior encompasses any and all of the actions performed by an organism, often in response to its environment or to the actions of another organism. Feeding behavior is only one of many behaviors influenced by natural selection.Slide10
Scope of Animal Behavior
Conflict, aggression, and territorialityCooperation, alliance building, and sociality
Competing for food and avoiding predatorsMigration and navigationBehavioral control of body temperatureSlide11
Scope of Animal Behavior
Courtship and mate choicePair bonding and fidelityBreeding and parental behavior
CommunicationLearning and tool useSlide12
Take-home message 9.1
Behavior encompasses any and all of the actions performed by an organism.
When a heritable trait increases an individual’s reproductive success relative to that of other individuals, that trait tends to increase in frequency in the population. Slide13
Take-home message 9.1
Behavior is as much a part of an organism’s phenotype, and as such it can be produced and shaped by natural selection.Slide14
9.2 Some behaviors are innate.
Nearly all physical traits of all organisms
are the products not only of genes but also of environmental conditions. Slide15
The degree to which a behavior depends upon the environment varies a great deal.
Instincts
or innate behaviorsExample: Fixed action patternRole of the EnvironmentSlide16
Triggered under certain conditions
Requires no learning
Does not varyOnce started, runs to completion Fixed Action PatternSlide17
Take-home message 9.2
Like any physical trait, behavior can depend on the environment for expression, though the degree of that dependence varies.
Instincts, or innate behaviors, develop without any environmental input. They are behaviors that are present in all individuals in a population and do not vary much from one individual to another or over an individual’s life span. Slide18
Take-home message 9.2
A fixed action pattern, a type of innate behavior, is a sequence of behaviors that requires no learning, does not vary, and runs to completion once started.Slide19
9.3 Some behaviors must be learned (and some are learned more easily than others).Slide20
Learning
Involves behaviors that are altered and modified over time in response to past experiencesTremendous variation among behaviors that require learning
Some are easy to learnOthers are notSlide21
Production of Behaviors
and the Role of the EnvironmentPrimates
—fear of snakesAppears not innate, but learnedSlide22Slide23
Prepared Learning
Behaviors that are learned easily and by all (or nearly all) individuals Snake-fearing behavior of monkeys
Acquisition of language in humans Slide24
Q
Why is it so much easier for an infant to learn a complex language than for a college student to learn biology?
Examine the evolutionary basis for the acquisition of certain behaviors.Slide25
Prepared Learning
However, organisms don’t learn everything with equal ease.Slide26
Q
Humanbabies quicklyand easily develop a fear of snakes. Yet they
don’
t
easily develop
a
fear of guns.
Why
?Slide27
Take-home message 9.3
In contrast to innate behaviors are those behaviors that are influenced more by the individual’s environment.
These behaviors require some learning and are often modified over time in response to past experiences.Slide28
Organisms are well-prepared to learn behaviors that were important to the reproductive success of their ancestors.
Organisms are less prepared to learn behaviors irrelevant to their evolutionary success.Take-home message 9.3Slide29
9.4 Complex-appearing behaviors don’t require complex thought in order to evolve. Slide30
“I must maximize my
reproductive success!”
Why do animals have sex? Why do people have sex? Slide31
Q
Do animals consciously act in order to improve their reproductive success?Slide32Slide33
Evolutionary Psychology
“In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation.” Charles Darwin, On the Origin of SpeciesSlide34
Take-home message 9.4
If certain behavior in natural situations usually increases an animal’s relative reproductive success, the behavior will be favored by natural selection.
The natural selection of such behaviors does not require the organism to consciously try to maximize its reproductive success.Slide35
Cooperation
, selfishness, and altruism can be better understood with an evolutionary approach
.Slide36
9.5 “Kindness” can be explained
Does unconditional love exist in the animal kingdom?
Altruistic behaviors—behaviors that come at a cost to the individual doing the behavior while benefiting the recipient. Slide37Slide38
Darwin’s Theory
Natural selection generally works to produce selfish behavior.Altruistic-appearing behavior is common.
Fatal to his theory?Slide39
Apparent Acts of Altruism
Kindness toward close relatives: kin selectionKindness toward unrelated individuals: reciprocal altruismSlide40
Take-home message 9.5
Many behaviors in the animal world appear to be altruistic.
In almost all cases, the apparent acts of altruism are not truly altruistic; they have evolved as a consequence of either kin selection or reciprocal altruism and, from an evolutionary perspective, are beneficial to the individual engaging in the behavior.Slide41
9.6 Apparent altruism toward relatives can evolve through kin selection.Slide42Slide43
Hamilton’s Rule
Altruistic-appearing behavior will occur when the benefits to close relatives are greater than the cost to the individual performing the behavior.They are really
acting in their own genes’ best interests.Slide44Slide45
Redefining an Individual’s Fitness
Direct fitnessAn individual’s total reproductive outputIndirect fitness
The reproductive output brought about by altruistic behaviors toward close kinInclusive fitnessThe sum of an individual’s indirect and direct fitness Slide46
Conflicts
Because different individuals do not share all of the same alleles, we should always expect some conflict.Example: gestational diabetesSlide47Slide48
Kin Selection & Conflict
The less closely related two individuals are, the more likely they are to experience conflict.Male lions “Cinderella syndrome”Slide49
Take-home message 9.6
Kin selection is apparently-altruistic behavior in which an individual that assists a genetic relative compensates for its own decrease in direct fitness by helping increase the relative’s fitness and, consequently, its own inclusive fitness.Slide50
9.7 Apparent altruism toward unrelated individuals can evolve through reciprocal altruism.Slide51Slide52
Vampire Bats
In many cases, individuals give blood to unrelated individuals. How might this behavior have arisen?Slide53
Are they repaid the favor?
Reciprocal AltruismStoring goodwillSlide54
Certain Conditions Must Be Met
Repeated interactions among individuals
The benefits to the recipient must be significantly greater than the costs to the donor.The ability to recognize and punish cheatersSlide55
Q
Why are humans among the few species to have friendships? Slide56
Q
Why is it easier to remember gossip than physics equations?Slide57Slide58
Take-home message 9.7
In reciprocal altruism, an individual engages in an altruistic-appearing act toward another individual.Although giving up something of value, the actor does so only when likely to get something of value at a later time. Slide59
Take-home message 9.7
Reciprocal altruism occurs only if:individuals have repeated interactionsbenefits to the recipient are much greater than costs to the donor
individuals can recognize and punish cheatersThese conditions are satisfied in humans but in few other species.Slide60
9.8 In an “alien” environment, behaviors produced by natural selection may no longer be adaptive.Slide61Slide62
Mismatch
Between the environment organisms are in and the environment to which they are evolutionarily adapted.Slide63
Take-home message 9.8When there is a mismatch between the environment organisms are in and the environment to which they are adapted, the behaviors they exhibit are not necessarily evolutionarily adaptive.Slide64
9.9 Selfish genes win out over group selection.
Does evolution ever lead to behaviors that are good for the species or population but detrimental to the individual exhibiting the behavior?Slide65Slide66Slide67
Take-home message 9.9
Behaviors that are good for the species or population but detrimental to the fitness of the individual exhibiting such behaviors are not generally produced in a population under natural conditions. Slide68
Sexual
conflict can result from disparities in reproductive investment by males and females.Slide69
9.10 There are big differences in how much males and females invest in reproduction.Slide70
Definition of “Male” and “Female”
A female
produces the larger gamete.A male produces the smaller gamete.The mother’s material contribution to the offspring exceeds the father’s.Slide71
Evolution of Differences in Male/Female Behaviors
Extent of energetic differences in their reproductive investment.Slide72
Why do males usually compete for females rather than the opposite?Slide73
Q
Why do males usually compete for females rather than the opposite?Slide74
Male and female reproductive investment differs across species
Examples:
MammalsGestation internalLactationSlide75
Male and female reproductive investment differs across species
Examples:Birds
Gestation externalNo lactationSlide76
Examples:
Fish and amphibiansExternal fertilization
Male and female reproductive investment differs across speciesSlide77
Evolution of Differences in Male/Female Behaviors
1) Extent of energetic differences in the reproductive investment
2) Paternity uncertaintyalso has profound influence on reproductive behaviorSlide78
Take-home message 9.10
In mammals and many other animals, there are important differences between males and females relating to reproduction.Slide79
Take-home message 9.10
Fertilization usually takes place in the female.Lactation occurs only in the female.
In species where fertilization occurs inside the female, males cannot be certain that offspring are their progeny.Slide80
Take-home message 9.10
These physical differences have led to the evolution of differences in male and female reproductive behavior.Slide81
9.11 Males and females are vulnerable at different stages of the reproductive exchange.Slide82Slide83
Predictions About Sex-Related Behavior
1) The sex that invests more will be more discriminating.
2) The sex that invests less will compete amongst themselves for access to the higher-investing sex. Slide84Slide85
Potential Exploitation at Different Stages of the Reproductive Process
At the point of mating
At the point of parental care to offspringSlide86
Two Critical Points To Keep In Mind
1. There is tremendous variability across
species in male and female behaviors.2. Throughout history, there have been many cases of people using observations and scientific findings to justify a wide variety of discriminatory thoughts and behaviors.Slide87
Take-home message 9.11
Differing patterns of investment in reproduction make males and females vulnerable at different stages of the reproductive process. This has contributed to the evolution of differences in their sexual behavior. Slide88
Take-home message 9.11
The sex with greater energetic investment in reproduction is more discriminating about mates, and members of the sex with a lower energetic investment in reproduction compete among themselves for access to the higher-investing sex.Slide89
9.12 Tactics for getting a mate: competition and courtship can help males and females secure reproductive success.Slide90Slide91Slide92Slide93Slide94
Take-home message 9.12
As a consequence of male-female differences in initial reproductive investment, males tend to increase their reproductive success by mating with many females and have evolved to compete among themselves to get the opportunity to mate. Slide95
9.13 Tactics for keeping a mate:
mate guarding can protect a male’s reproductive investment
When offspring survival can be enhanced with greater parental investment…Slide96
Tactics for Keeping a Mate:
Mate Guarding
When offspring survival can be enhanced with greater parental investment…there is an incentive for males to provide some parental care…makes him vulnerable to paternity uncertainty.Slide97
Tactics for Keeping a Mate:
Mate Guarding
When offspring survival can be enhanced with greater parental investment…there is an incentive for males to provide some parental care…even though such behavior makes him vulnerable to paternity uncertainty.Slide98
Q
Why do so few females guard their mates as aggressively as males do?
Mate guarding in order to reduce vulnerabilityAttempt to reduce paternity uncertainty“Danger zone” for malesSlide99
Mate Guarding:
From Simple to MacabreSlide100
Copulatory Plugs
Reptiles, insects, and many mammalian speciesMales block the passage of sperm into the female
Coagulated sperm and mucusSlide101Slide102
Take-home message 9.13
Mate guarding can, in general, increase reproductive success by reducing additional mating opportunities for a partner…
…and can improve a male’s reproductive success by increasing his paternity certainty and thus reducing his vulnerability when he makes investment in offspring.Slide103
9.14 THIS IS HOW WE DO IT
When paternity uncertainty seems greater, is paternal care reduced?Slide104
The System
Bluegill sunfish in lakes and rivers in North America.Males guard eggs.
“Cuckold males.”Slide105
Experiment 1
34 randomly chosen nests.Cuckold males under a glass container, visible to by male in nest.
Predator fish under a glass container.Parental care evaluated.Slide106
Would you expect the presence of cuckold males to influence a nest owner’s perception of paternity certainty?
Prediction a: The presence of the cuckold males should reduce the nest owner’s paternity certainty and therefore reduce his egg-guarding efforts.Slide107
Should the presence of cuckold males influence a nest owner’s perception of paternity certainty after
the offspring hatch?Why or why not?
Prediction b: After the offspring hatch, the nest owner can determine whether they are his genetic offspring, so he should not exhibit any reduction in parental care relative to males in the control group.Slide108
Results of Experiment 1
How much did the presence of cuckold males reduce egg guarding?
How much did it alter offspring guarding?
Egg Guarding
Offspring Guarding
Prediction
Reduced
Unchanged
Actual Results:
No rivals (control)
80 ± 10
90 ± 10
Rivals present
52 ± 7
95 ± 10
Change in care
Reduced
Unchanged
Parental Care ScoreSlide109
Experiment 2
20 randomly chosen nests.Removal of one-third of the eggs from each nest and replacement with unrelated fertilized eggs from another male’s nest.
Predator fish under a glass container.Parental care evaluated.Slide110
Should a nest owner show reduced parental care of eggs that were swapped in from another nest?
Why or why not?Prediction a:
Prior to hatching of the eggs, the nest owner should exhibit the same egg-guarding efforts regardless of whether or not the eggs were swapped.Slide111
Should a nest owner show reduced parental care of hatched offspring after eggs were swapped?
Why or why not?Prediction b:
After the offspring hatch, because the nest owner can determine whether they are his genetic offspring, he should exhibit reduced parental care relative to the control males.Slide112
Results of Experiment 2
How much was egg guarding reduced when unrelated eggs were swapped into the nest?
How much was offspring guarding changed? What conclusions can you draw from these results?
Egg Guarding
Offspring Guarding
Prediction
Unchanged
Reduced
Actual Results:
Eggs not swapped (control)
90 ± 10
73 ± 9
Eggs swapped
95 ± 10
50 ± 8
Change in care
Unchanged
Reduced
Parental Care ScoreSlide113
Take-home message 9.14
Experimental manipulations of the cues of paternity certainty can increase or decrease a male’s parental investment in accordance with the prediction that decision making about parental investment reflects perceptions of genetic relatedness.Slide114
9.15 Monogamy versus polygamy: mating patterns can vary across human and animal cultures.Slide115Slide116
Mating Systems
Polygamywhen some individuals attract multiple mates while other individuals attract none
Monogamy most individuals mate and remain with just one other individualSlide117
Mating Systems
Polygamy subdivided into:Polygyny
individual males mate with multiple femalesPolyandryindividual females mate with multiple malesSlide118
Mating Systems Are Not Easy to Define
Three issues complicate the task: 1) differences between animals’ mating behavior and bonding behavior
Pair bond—appears monogamous Slide119
Mating Systems Are Not Easy to Define
Three issues complicate the task: 2) mating system variation within the speciesSlide120
Mating Systems Are Not Easy to Define
Three issues complicate the task:
3) males and females vary in their mating behaviorSlide121
Examination of Birds and Mammals Reveals One Sharp SplitSlide122
Are humans monogamous or polygamous?Slide123
Take-home message 9.15
Mating systems—monogamy, polygyny, polyandry—describe the variation in number of mates and the reproductive success of males and females.
They are influenced by the relative amounts of males’ and females’ parental investment.Slide124
9.16 Sexual dimorphism is an indicator of population’s mating behavior.Slide125Slide126
Body Size Is an Important Clue to Behavior
Selection for larger and larger body size when competition is high
Coloration can also be a clue to behaviorMale-male competition sometimes results in differences in physical appearance between the sexesSlide127
It’s almost impossible to distinguish males from females in most bird species.
Why does that mean they are monogamous?Slide128
Men are bigger than women.
What does that tell us about our evolutionary history of monogamy versus polygamy?Slide129
Take-home message 9.16
Differences in the level of competition among individuals for mating opportunities can lead to male-female differences in body size and other aspects of appearance.Slide130
Take-home message 9.16
In polygynous species, this results in larger males that are easily distinguished visually from females.In monogamous species, there are few such differences between males and females.Slide131
Communication
and the design of signals evolve.Slide132
9.17 Animal communication and language abilities evolve.Slide133
Chemical Communication in AnimalsSlide134
Communication
An action or signal on the part of one organism that alters the behavior of another organism.
What types of animal behavior require communication?What types of communication do animals use?Slide135
Types of Animal Communication
Chemical Acoustical VisualSlide136
Complex Forms of Communication
Honeybee waggle dance
What is language?Slide137
How is language identified?
HoneybeesAmerican Sign Language taught to
orangutansHuman languageSlide138
Take-home message 9.17
Methods of communication—chemical, acoustic, and visual—have evolved among animal species, enabling them to convey information about their condition and situation. These abilities influence fitness and the evolution of almost all other behaviors.Slide139
9.18 Honest signals reduce deception.
Conveying accurate informationSlide140Slide141
Honest Signal
Cannot be faked
Given when both the individual making the signal and the individual responding to it have the same interestsCarries the most accurate information about an individual or situationSlide142
Deception Evolves!
“Begging” alleleEvolutionary “arms race”
Unambiguous signalsSophisticated patterns of deceptionAn organism’s phenotype includes its behaviorsSlide143
Take-home message 9.18
Animals have evolved to rely primarily on signals that cannot easily be faked, in order to gain the maximum amount of information.