Important words and concepts
from Chapter 51, Campbell & Reece, 2002
(3/25/2005):
by Stephen T. Abedon (abedon.1@osu.edu)
for Biology 113 at the Ohio State University
|
|
Course-external links are
in brackets Click [index] to access site index Click here to access
text’s website Vocabulary
words
are found below |
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(1) Chapter title: Behavioral Biology
(a)
[glossary of terms used in animal behavior and evolution
(Behavioral Ecology – Jane Brockmann – University of Florida)]
(b)
[behavioral biology
(Google Search)]
[index]
(a)
We expect natural selection
to attempt to maximize the Darwinian fitness
associated with the traits possessed by organisms
(b)
The goal of a behavioral ecologist is to explain behaviors in terms of
their impact on Darwinian fitness
(c)
As with any trait (given an “adaptationist paradigm”), the behavior
of an organism, too, we expect to be Darwinian-fitness enhancing
(d)
That is, behaviors that reduce Darwinian fitness we predict will be
lost from gene pools while behaviors that increase
Darwinian fitness we expect to increase in frequency within populations
(e)
Note, however, that while behaviors often have underlying genetic
components, the ability of organisms to learn complicates our understanding of
behavioral evolution; nevertheless, we have an expectation that organisms will
have a tendency to behave in a manner that enhances their Darwinian fitness
(f)
[behavioral ecology
(Google Search)]
[nebraska behavioral biology group] [animal behaviour--zoological
record (Biosis)] [index]
(a)
What is behavior?
(i)
Defined extremely broadly, behavior is how organisms act in response to
environmental stimuli, with the word "act" (as well as the phrase
"environmental stimuli") left somewhat ambiguous
(ii)
Clearly organisms act or react physiologically to all sorts of
environmental stimuli (e.g., Escherichia
coli's modification of gene expression in response to low levels of the sugar glucose and high levels of sugar lactose)
(b)
The study of behavior becomes interesting when behaviors
(i)
are not obviously in the organism's best interest
(ii)
when the cost of the behavior is high even given that ultimately the
behavior serves the organism's Darwinian interests (e.g., in terms of energy
required to learn or display the behavior, or when the maintenance of costly
anatomical features, e.g., a large brain, is necessary for the display of the
behavior), or
(iii)
when the behavior appears to be overly simplistic but still sufficient
to get the job done (e.g., FAPs)
(c)
We would say that an organism's behavior is optimized when the
organism's Darwinian fitness is optimized given the display of that behavior
relative to the display of some alternative behavior, including the display of
no behavior at all (“If you choose not to decide,
you still have made a choice.”)
(d)
Behavior typically influences the acquisition of energy, nutrients,
sex, help in child rearing, removal of ectoparasites,
survival, establishment and maintenance of dominance hierarchies, etc.
(e)
Note that whereas behavior is traditionally studied with animals,
unless defined in some way that excludes all other kingdoms (e.g., requiring
muscles or a nervous system) then behavior is the province of members of all
kingdoms (plus their viruses); nevertheless, behavior obviously is displayed
with a greater complexity by animals so the animal-emphasis of behavioral
ecology is quite justified
(f)
[behavior (Google Search)]
[index]
(a)
When we question why a behavior occurs (or, for that matter, why any
trait exists), we are posing a question of ultimate causation
(b)
Ultimate causation is simply another way of saying optimization of Darwinian fitness
(c)
The ultimate cause of a behavior is its increase in frequency within a
population due to the greater Darwinian fitness that results from organisms
engaging in that behavior
(d)
Thus, when questioning ultimate causation, one is simply asking why a
behavior evolved
(e)
The hallmark of the discipline called behavioral ecology
is its emphasis on determining the ultimate causation of behaviors
(i)
Understanding the ultimate causation of some behaviors can be very
straightforward (a female songbird mates to have babies)
(ii)
Interesting questions in
behavioral ecology are those that are less straightforward (e.g., a female songbird
mates with someone other than her lifetime mate or why a bird would push her
own eggs out of her own nest)
(f)
[ultimate causation
(Google Search)]
[index]
(a)
In contrast with ultimate causation, proximate causation
involves the mechanics of how a behavior occurs including
(i)
how stimuli are received
(ii)
how received stimuli are translated into a response, and
(iii)
the mechanisms underlying the response (i.e., the behavior)
(b)
A behavioral ecologist assumes that the proximate cause of a behavior
is simply the mechanism underlying the means by which a behavior is
manifest
(c)
"Thus, the 'how' and 'why' questions about animal behavior are
related in their evolutionary basis: Proximate mechanisms produce behaviors
that ultimately evolved because they increase fitness in some way."
(d)
As such, a behavioral ecologist is interested in proximate causation
only to the extent that these mechanisms serve to constrain the evolution of
specific behaviors
(e)
It should not be overlooked that understanding how behaviors are
constrained by an organism's anatomy and physiology is highly relevant;
however, otherwise becoming mired down in the details of the anatomy and
physiology of a behavior can be somewhat distracting to one's understanding of
the ecology of a behavior, so proximate causation is frequently accepted as a
given (i.e., the behavior happens so the organism must be anatomically,
physiologically, and mentally capable of expressing the behavior)
(f)
[proximate causation
(Google Search)]
[links related to animal
perception (Animal Learning &
Cognition)] [index]
(6) Umvelt (supplemental discussion)
(a)
This is the term used to describe the means by which proximate causation underlies the display of a given behavior,
that is, the anatomical, physiological, and environmental (?) context
underlying and allowing a behavior to occur
(b)
[umvelt (Google Search)]
[how animals see (Animal Learning &
Cognition)] [index]
(a)
Behavioral ecology as a discipline had its roots in the more proximate causation-concerned field of ethology
(b)
Ethology, however, is less concerned about learning and more concerned
about innate, not-learned behaviors
(c)
"One of the major findings of ethology was that animals can carry
out many behaviors without ever having seen them performed. In other words,
many behaviors are innately programmed. And while such behaviors seem
purposeful because they are clearly beneficial, they are carried out in ways
that show the animals are unaware of the significance of their actions."
(d)
These are examples of innate behaviors:
(e)
[ethology (Google Search)]
[ethology and evolution on the web (The International Society for Human Ethology)]
[index]
(8) Fixed action
patterns (FAP) [sign
stimulus, releaser]
(a)
A fixed-action pattern is a series of behaviors that are both innate
and, typically, are completed in full once initiated (even if their completion
is laughably inappropriate)
(b)
The initiation of a fixed action pattern is in response to an external
sensory stimulus known as a sign stimulus
or a(n innate) releaser
(c)
The reason why FAPs are not always appropriate is because the releaser
for the action is often a proximate correlate
to the stimulus ("a limited subset of the available sensory
information") that while the FAP is ultimately (i.e.,
evolutionarily) a response to some full stimulus
(d)
"We can think of a FAP as the innate ability of an animal to
detect a certain stimulus associated with the animal's umvelt, combined
with an innate behavioral program that is activated by the stimulus to direct
some kind of motor activity."
(e)
"In the case of a FAP, the animals are behaving more like
robots."
(i)
However, the important thing to keep in mind is that the FAP under natural
conditions typically represents the energetically minimal investment in the
display of a behavior that otherwise is good enough (i.e., evolution is not
just optimizing the outcome of the behavior but also optimizing the efficiency
of the behavior such that behavioral outcome for energy invested is maximized)
(ii)
"The ability to confront novel stimuli, learn about them, and
adjust behavior is a hallmark of both intelligence and self-awareness. The
evolution of intelligence is costly, in both the development of the neural
tissue necessary to process the information and its metabolic maintenance. In
addition, the evolution of intelligence requires dramatic changes in life
history patterns, such as long juvenile phases and high parental investment per
offspring. For most species, these costs, measured as reductions in
reproductive fitness, far outweigh the costs of an occasional inappropriate use
of FAPs, and extensive intelligence has not evolved in many animal
groups."
(iii)
"Some ethologists have suggested that the use of
simple cues to release programmed behavior prevents an animal from wasting time
processing or integrating a wide variety of input. Perhaps a better way of
interpreting the situation has to do with the limitations of innate behavior
and how it evolved. A frog's sensory-neural network for detecting movement is
probably much less complex than the apparatus that would be necessary to
rapidly distinguish a fly from another object of similar size. In any case,
simple cues usually work quite well in an animal's normal sensory world, though
not in the experimental world ethologists often create."
(f)
[egg rolling animated gif
(1.8 MB file), chick hatching movie
(600 KB) (Behavioral Control Systems)]
[fixed action patterns,
sign stimulus, innate releaser (Google Search)]
[stimuli and innate behavior
(Bio 170 – Animal Behavior
– Barry Sinervo)] [index]
(a)
Learning is synonymous with behavioral modification such that, ideally,
a behavior is further optimized by the change
(b)
Learning can optimize behavior most obviously in a short term sense;
however, for behavior to be truly optimized, it must be optimized in a
Darwinian sense
(c)
"Nearly all biologists today agree that most behavior is a
consequence of genetic and environmental influences. Even though an animal may
not have to witness a FAP because the basic behavior is innate, learning is
still involved. Most FAPs improve with performance, as animals learn to carry
them out more efficiently."
(d)
Learning may be differentiated into a number of different types and
associated concepts:
(i)
Maturation (not learning at all)
(ii)
Habituation (learned ignoring)
(iii)
Imprinting (learned sign stimulus)
(iv)
Associative learning
·
Classical conditioning (Pavlov's dog)
·
Operant conditioning (trial and error learning)
(v)
Observational learning (copying)
(vi)
Play
(practicing)
(vii)
Insight learning (assessment of novel
situations)
(e)
[animal learning (Google Search)]
[index]
(a)
Learning must be operationally distinguished from maturation
(b)
That is, just because an animal improves its performance of a behavior
with time does not mean that the animal is improving through learning; it could
instead mean that the animal was physiologically or anatomically unable to
properly or fully display the behavior until they have reached an appropriate
developmental stage
(c)
Such development-associated improvements in behaviors occur via
maturation
(d)
[animal maturation and learning
(Google Search)]
[index]
(a)
Habituation is one means by which animals adapt behaviorally to their
environment (i.e., learn)
(b)
Habituation is the learned ignoring of a stimulus
(c)
This occurs when an animal learns that a stimulus is not appropriately
correlated with the expected full stimulus
(d)
Thus, habituation is a means of, for example, energy conservation
employed when proximal stimuli are not followed by
subsequently expected stimuli
(f)
[animal habituation and
learning (Google Search)]
[index]
(12) Imprinting (critical period)
(a)
(b)
Two things distinguish imprinting from other types of learning
(i)
An imprint, once learned, is never forgotten (i.e., imprinting is
irreversible)
(ii)
An imprint can only be learned during a critical period, which is defined (somewhat tautologically) as the
limited time during which an imprint may be learned
(c)
"While a critical period and irreversibility characterize
imprinting, it now recognized that these phenomena are not always rigidly
fixed." That is, it is possible, though not easy, in some
situations/species for an animal to eventually modify its behavior to disregard
imprinting
(d)
See Figure 51.9, Imprinting
(e)
[imprinting, definition]
[imprinting, imprinting "critical
period" (Google Search)] [index]
(a)
Associative learning is the association of one stimulus with another
(b)
See classical conditioning and operant conditioning as examples
(c)
[associative learning
(Google Search)]
[index]
(a)
Classical conditioning is the occurrence of associative learning following repeated, correlated exposure
to two stimuli
(b)
In classical conditioning each stimulus becomes equivalent in terms of
the behavioral response
(c)
Thus, otherwise irrelevant correlates to relevant stimuli can come to
induce identical responses (e.g., the ringing of bells with the smell/taste of
food; the opening of refrigerators or the rustling of plastic bags and the
whistling response by guinea pigs used to being fed “fresh” produce)
(d)
[classical conditioning
(Google Search)]
[index]
(a)
Operant conditioning is trial-and-error learning
(b)
Operant conditioning works (in an ultimate, Darwinian
sense) so long as an animal possesses a reasonable means of distinguishing good
from bad
(i)
Using these terms in their ultimate, Darwinian sense, e.g., a good
thing results in more offspring while a bad thing results in less offspring
(c)
This means of distinguishing good from bad requires either a reasonable
idea of the future consequences of one's actions (e.g., as humans supposedly
possess) or some kind of physiological indicator of good and bad, which in
animals is represented (probably) as pleasure and pain
(d)
Thus, animals continue to do things that give them pleasure while
refraining from doing things that cause them pain
(e)
Keep in mind that the reaction of pleasure or pain is itself a product
of natural selection, such that things that tend
to enhance Darwinian fitness tend to be pleasure-filled while those things that
tend to diminish Darwinian fitness are painful
(i)
Of course, if an environment changes then the correlation between
painful and diminishment of Darwinian fitness or pleasurable and enhancing of
Darwinian fitness may be lost
(f)
Note that while classical conditioning
is the association of two stimuli such that an animal anticipates a result (one
the stimuli; e.g., food) given the stimulation by the other (e.g., a bell), in
operant conditioning the second stimulus in a sense is internal rather
than external: the animal associates stimuli either with pleasure or with pain
and learns to seek out those stimuli that elicit the former and avoid those
that elicit the latter; thus, classical conditioning involves the association
of two external stimuli while operant conditioning involves a learned
association between an external stimulus and an internal state
(g)
See Figure 51.11, Operant
conditioning
(h)
[operant conditioning
(Google Search)]
[index]
(a)
Observational learning is the copying of the actions of others
(b)
The assumption is that others, by having survived, etc., possess
behaviors that are worth knowing
(c)
Note that by this logic the worth of another's behavior (i.e.,
whether that behavior is worth copying) diminishes with the age of the other
such that while the behavior of an older individual may be worth copying
(i)
The behavior of a same-aged individual is less worthwhile
(ii)
The behavior of a younger individual has the least worth of all
(d)
[observational learning
(Google Search)]
[index]
(a)
Play is essentially practice
(b)
The more we practice, the better we get at something (which ideally
enhances our survival or reproductive success); this "getting better"
can be in terms of the acquisition of skill or in the development and
maintenance of musculature that will be relevant to possess once even extended
parental care is no longer available
(c)
Consequently, the finding of pleasure in play is our body's way of
making sure that we practice
(d)
Note that play is an expensive way to learn:
(i)
It requires a big brain that is capable of learning complex behaviors
(ii)
To the extent that play requires energy while exposing individuals to
risk, play is a costly behavior in and of itself
(e)
[play (with over 30
million hits, I suspect that “play” is not the most useful search strategy) (Google Search)]
[index]
(18) Insight learning (supplemental discussion)
(a)
This is the performance of a novel behavior that occurs as a consequence
of thinking through the behavior and at least some of its consequences
(particularly short-term consequences) before initiating the behavior, i.e.,
basically figuring something out for oneself without continuous, direct
environmental feedback
(b)
Only the very smartest animals are capable of insight learning
(c)
[insight learning (Google Search)]
[index]
(19) Moving and timing behaviors
(a)
A number of animal behaviors might (for convenience) be described as
movement and timing behaviors (a category I've made up essentially to serve as
a heading for the discussion that follows); these include
(i)
Rhythmic behaviors (supplemental discussion)
(ii)
Kinesis
(iii)
Taxis
(iv)
Migration
(b)
[(Google Search)]
[index]
(20) Rhythmic behaviors (supplemental discussion)
(a)
(b)
The mechanisms underlying these rhythmic behaviors may be categorized
as endogenous or exogenous (coming from within the animal and coming from the
animal's environment, respectively)
(c)
Typically the exogenous signal is light (i.e., the stuff that comes
from the sun)
(d)
For example, a typical animal will be able to almost-display rhythmic
behaviors at the appropriate times without exogenous signals (e.g., if deprived
or light or changes in light) but will only not be able to display behaviors at
appropriate times with high accuracy if deprived of the exogenous signals
(e)
Note that this endogenous-exogenous system allows animals to innately
display appropriate behaviors at nearly appropriate times independently of
fallible exogenous signals, but still adapt to changes in exogenous signals,
e.g., as day lengths change with the seasons
(f)
[rhythmic behaviors,
circadian rhythm, chronobiology (Google Search)]
[index]
(a)
Kinesis is a movement behavior such that movement randomly occurs given
the presence of a stimulus; in practice, an organism will tend to settle down
in a region that is preferred by tending to move particularly when not present
in the preferred location
(b)
Kinesis is a mechanism of movement that involves activity only so long
as a stimulus is present (or, alternatively, only when a signal is absent)
(c)
For example, an animal might move only when the environment is in some
way unfavorable; this movement does not occur in a specific direction but
instead is randomly directed, with attainment and maintenance of the animal
within a more favorable environment occurring simply because less movement
occurs when the movement-associated stimulus is not present
(d)
[Kinesis is the animal equivalent of the answer to “Why do so many
leaves collect in my pool?” The answer is that fallen leaves often may be blown
by the wind. However once they are sufficiently wet they no longer may be blown
around. These leaves are capable of more or less freely moving about until they
land in your pool. Thus, they tend to collect in bodies of water.]
(e)
[A kinesis-like mechanism probably also explains what radio station you
listen to. That is, as you are flicking through the “dial,” your tendency is to
change stations when a station plays a song (or whatever) that you do not like.
Therefore it is the stations that most frequently play things that you don’t
(or least) want to listen to that will be changed the most. Thus, chances are
you the station you listen to is more the one that plays the music you find
least objectionable rather than the one that plays the music you enjoy the
most.]
(f)
[One likely can generalize the above scenario to all sorts of aspects
of your life from produce to mate choice. For instance, the above arguments
probably also help to explain the American diet: We are far more interested in
obtaining foods that we don’t find objectionable than obtaining foods that we
find absolutely wonderful. As a consequence, it is very difficult to find
absolutely wonderful food in
(g)
[animal kinesis (Google Search)]
[index]
(a)
Taxis, by contrast with kinesis, is directed movement either
toward or away from a stimulus
(b)
[animal taxis (Google Search)]
[index]
(a)
Migration is the regular (annual) movement of animals over long
distances
(b)
Migrating animals find their way via one of three mechanisms
(i)
Piloting ("map")
(ii)
Orientation ("compass")
(iii)
Navigation ("map" and "compass")
(c)
[animal migration (Google Search)]
[index]
(a)
Piloting is the movement from one landmark to another such that terrain
remains familiar throughout the migration
(b)
Because of the requirement that an animal have essentially memorized
the directions for the entire trip (an internal map), piloting is typically
employed only for relatively short trips (or trips made over well land-marked
land, e.g., over a well-worn path)
(c)
[(Google Search)]
[index]
(a)
Orientation involves straight-line travel in a direction that is
globally oriented (e.g., flying by compass)
(b)
Compasses are not necessarily artifacts (i.e., man-made devices) but
may also be small, sensory magnets found within an animal’s head
(c)
Alternatively, many animals appear to orient using the position of the
sun (or stars) and innate knowledge of the time of the day
(d)
[animal orientation Google Search)]
[index]
(a)
Navigation involves possessing both a map and a compass
(b)
Maps are not necessarily paper things, i.e., one can possess a “map”
within one's head
(c)
[animal navigation Google Search)]
[index]
(27) Foraging (generalists, specialists)
(a)
Foraging is the behavior(s) an animal employs to feed
(b)
"Food habits are a fundamental part of an animal's niche and may
be shaped in part by competition with other species."
(c)
Animals may be categorized in terms of their foraging behaviors into
generalists and specialists
(d)
Specialist tend to be better at acquiring specific kinds of food,
employing morphological adaptations as well as behavioral adaptations and
culture to maximize their yield of specific foods
(e)
Generalists are not as good at acquiring any particular kind of food,
but generalists potentially have available to them many more kinds of food;
"Generalists cannot be as efficient at securing any one type of food, but
they have the advantage of having other options if a preferred food becomes
unavailable."
(f)
[foraging, foraging behaviors
(Google Search)]
[index]
(a)
Generalists, too, can specialize in the acquisition of
specific food stuffs, particularly by temporarily specializing
(b)
When specializing the generalist employs a specific search image which
is a behavioral algorithm for catching/obtaining a certain kind of food
(c)
This search image will be employed, and even improved upon, until a
decline in the abundance of that food stuff leads to literally diminishing
returns; then, rather than suffering without adequate food supplies, the
generalist can simply switch to a new food type and new search image
(d)
[animal "search
image" -engine (Google Search)]
[index]
(a)
What makes one food type and search image preferable to another?
(b)
Basically, ideally, an organism chooses to consume the food that is
easiest to acquire on a per-unit-nutrient basis and in optimal foraging the
benefits of a given forage essentially are optimized relative to costs
(c)
Thus, for example, slow, tasty, and abundant things are consumed
preferentially to fast, rare, obnoxious things
(d)
Organisms that perform such a cost-benefit analysis are said to be
optimizing their foraging
(e)
"Optimal foraging theory predicts that natural selection will favor animals that
choose foraging strategies that maximize the differential between benefits and
costs. Benefits are usually considered in terms of energy (calories) gained.
However, other optimization criteria, such as specific nutrients, are sometimes
more important than energy. Costs or tradeoffs associated with foraging consist
of the energy needed to locate, catch, and eat food; the risk of being caught
by a predator during feeding; and time taken away from other vital activities,
such as searching for a mate."
(f)
As a consequence of the complexity of the cost-benefit analysis of
optimal foraging behavior, an organism does not necessarily do all necessary
calculations in its head prior to subduing food, but instead has certain
rule-of-thumb behavioral tendencies representing evolutionary algorithms
defining what to eat under what circumstances; it is typically these
rule-of-thumb behavioral tendencies that are optimized in optimal foraging
behavior
(g)
["Behavioral ecologists use (many) factors to predict how an
animal will forage given a particular set of conditions. Their goal is not to
test whether animals in fact forage optimally, but to use the expectations of
optimality as a guide to organizing research and generating testable
predictions. When their predictions are borne out, researchers come closer to
understanding the major factors that shape an animal's foraging behavior. When
their predictions are not borne out, they have still made progress because they
know they must consider additional factors. Predictions in optimal foraging
studies are usually quantitative; they are frequently based on direct
measurements of the calories an animal must expend to secure particular food
items and the calories it gains by doing so. Numerous studies of many species
show that animals tend to modify their behavior in a way that keeps their
overall ratio of energy intake to energy expenditure high. Their ability to do
this is sometimes quite surprising. The smallmouth bass is somehow able to
factor in all the relevant variables and forage in a highly efficient manner,
switching between minnows and crayfish as conditions change. The proximal mechanisms responsible for this process are not
known. They must include innate cues, but experience undoubtedly modulates
behavior."]
(h)
[optimal foraging (Google Search)]
[optimal foraging theory
(Bio 170 – Animal Behavior
– Barry Sinervo)] [index]
(a)
Social behavior is interactions between two or more organisms,
typically animals, usually conspecifics
(b)
Some animals are more social than others, with the minimal social
behavior necessary between sexually reproducing animals being that associated
with mating
(c)
"The complexity of behavior increases dramatically when
interactions among individuals are considered. Aggression, courtship,
cooperation, and even deception are part of the behavioral landscape of social
behavior. Social behavior has both costs and benefits to members of those
species that interact extensively."
(d)
[social behavior (Google Search)]
[index]
(a)
Sociobiology is the application of evolutionary theory to the study of
social behavior (just as behavioral ecology is the application of
evolutionary theory to the study of animal behavior)
(b)
“Social scientists regard culture – everything from eating habits to
language – as an entirely human invention, one that develops arbitrarily…
Sociobiologists, by contrast, emphasize that learned behavior, and indeed all
culture, is the result of psychological adaptations that have evolved over long
periods of time. Those adaptations, like all traits of individual human beings,
have both genetic and environmental components… Social science… promotes
erroneous solutions, because it fails to recognize that Darwinian selection has
shaped not only human bodies but human psychology, learning patterns and
behavior as well.” (Randy Thornbill and Craig T. Palmer, 2000, Why men rape. The
Sciences 40(1 – January/February): 30-36) (The Sciences is a
publication of the New York Academy of Sciences)
(c)
[sociobiology (Google Search)]
[Behavioral Ecology and
Sociobiology (a journal) (Springer)] [index]
(a)
Aggressive behavior between conspecifics usually involves fighting over
a limiting resource such as food, water, space, or mates
(b)
Depending on the importance of the resource as well as its scarcity,
agonistic behavior can range from all-out fighting to the death to much safer
ritualistic behavior
(c)
Animals typically lack action-at-a-distance weapons such as those
possessed by humans (e.g., guns) so risk injury or even death whenever they
engage in aggressive behavior
(d)
Consequently, animals often avoid fighting unless there is a sure
indication that they will win without incurring injury and if the resource is
worth fighting over
(e)
Animals often possess sophisticated rituals in which they attempt to
bluff their opponent into backing down, and animals also often have a good
sense of when to retreat as losers from an otherwise hopeless, potentially
injurious cause
(f)
Agonistic displays by a human female and a mandrill male:
(h)
[agonistic behavior
(Google Search)]
[index]
(a)
One way in which agonistic behavior is avoided is by
knowing one's place in the scheme of things and then avoiding any behaviors
that might be interpreted as threatening to those possessing a higher rank
(b)
Animals that are higher on dominance hierarchies risk injury to attain
that status (and often must commit large amounts of energy to maintaining that
status), but benefit by gaining preferred access to food or mates for
themselves and also potentially for their offspring
(c)
Thus, a dominance hierarchy represents an institutionalized (though not
necessarily completely static) snapshot of the results of previous agonistic
behavior, and are advantageously maintained by everyone to the extent that
previous fighting need not be repeated
(d)
[dominance hierarchies
(Google Search)]
[index]
(34) Territoriality (home
range)
(a)
Another way that all-out fighting is avoided is by institutionalizing
conflicts into territories (dominance hierarchies
might also be considered to be territories, ones where social position is
defended rather than space)
(b)
A territorial individual will typically defend a specific area
particularly against intrusion by conspecifics
(i)
Conspecifics are individuals that an individual is most directly in
competition with, against which an individual possesses a reasonable chance of
winning a fight, and with which one's mate might fool around
(ii)
Territories that are not defended are instead called home ranges
(c)
Territories may be permanent or temporary, may be defended by one
individual or many, and may be established to guard space, food, mates, etc.
(d)
Territory owners are more likely to win fights against would-be
trespassers; this is probably because the owner
(i)
Has more to lose and therefore is willing to risk more to win a fight
(since the owner but not the trespasser has learned the territory)
(ii)
May be an older, more experienced fighter (since younger, less
experienced fighters presumably are less likely to have acquired a territory)
(e)
In many species territories are indicated by more than just agonistic behavior, including expressions of sound and scent intended
to warn off potential trespassers
(f)
Note that territoriality represents an uneven partitioning of resources
that can have the effect of minimizing the excursion of populations beyond an
ecosystem's carrying capacity for that organism
(i)
(thus, one would predict that K selection and territoriality would
often go hand in hand; we will consider K selection in some detail in
the next chapter)
(g)
[territoriality (Google Search)]
[index]
(a)
"All aspects of reproductive behavior receive extensive attention from
behavioral ecologists. The reason is that researchers can often determine the
number of young an individual produces, which comes very close to determining
an animal's fitness. The correlation between measurable behaviors and fitness
may not be as strong for other aspects of behavioral ecology, such as optimal
foraging."
(b)
[mating behavior (Google Search)]
[index]
(a)
(b)
Part of courtship behavior can additionally involve some degree of
assessment by one individual of the other individual
(c)
In addition to assuring that matings are successful in the sense that
they produce viable offspring, an animal additionally is motivated to increase
the likelihood of the success of offspring by finding, via courtship, mates
that have the best genes or behaviors, i.e., animals, given a choice, like to
"marry up"
(d)
[courtship behavior
(Google Search)]
[The Mating Habits of
Earthbound Humans (a mockumentory)] [index]
(a)
An animal that is destined to invest a lot of time and energy in the
parenting of offspring would prefer to mate with individuals who bring more to
the mating rather than less
(b)
Typically, especially given internal fertilization, the gender that
invests the most in offspring is the female
(c)
This investment can come in the form of large gametes, internal
development of the young, or raising the young following birth or hatching
(i)
Most females contribute to a least one of these parental investments
(ii)
Many males do not (though, to be fair, there are many males out there
that contribute to the sheltering and nourishment of females, the sheltering or
internal development of young, and the raising of young)
(d)
Sexual selection is the means by which a gender (typically males)
either compete directly over a female or compete for a female's favorable
attention; these battles in turn select for secondary sexual characteristics
that aid in the fighting of battles over females or the attracting of females
(e)
In some species, e.g., humans, both parents often invest mightily in
the raising of offspring and sexual selection
consequently impacts directly on both genders
(f)
[parental investment
(Google Search)]
[index]
(38) Mating systems [promiscuous,
monogamous, polygamous, polygyny, polyandry]
(a)
(b)
Promiscuous mating systems exist particularly where one parent (e.g.,
the guy) does not participate at all in the raising of offspring whereas
monogamous relationships occur particularly when two parents share the raising
of children
(c)
Various mating-system types include:
(i)
Promiscuous = low likelihood of
subsequent mating with same individual
(ii)
Monogamous = high likelihood of
subsequent mating with one individual
(iii)
Polygamous = high likelihood of
subsequent mating with more than one individual
(iv)
Polygyny = one male mates with
several females
(v)
Polyandry = one female mates with
several males
(d)
It is important to keep in mind that a mating system usually exists to
serve some ultimate cause, i.e., enhancement of both male
and female fitness
(e)
[mating systems, promiscuous mating systems,
monogamous mating systems,
polygamous mating systems,
polygyny, polyandry, (Google Search)]
[index]
(a)
Altruism is cooperative behavior in which the actor's Darwinian fitness is reduced by the behavior
(b)
Particularly, this is when the actor's individual (as opposed to inclusive) fitness is reduced by the behavior
(c)
[altruism (Google Search)]
[index]
(a)
Cooperative behaviors are acts that increase the Darwinian fitness of others
(b)
These same acts may or may not increase the Darwinian fitness of the
actor, or may even decrease the fitness of the actor
(c)
Since natural selection favors individuals who increase their own
fitness (i.e., not necessarily that of other's), it is not always obvious nor
easy to understand either why cooperative behavior occurs or how it might have
evolved
(d)
The evolution of cooperative behavior is typically considered to result
as a consequence of either
(i)
Kin selection
(iii)
Group selection
(e)
["cooperative behavior"
ecology (Google Search)]
[index]
(a)
Kin selection is another way of saying that it pays to help those to
whom we are most closely related
(b)
Why?
(i)
Individuals with which an individual is closely related share genes
including genes that code for cooperative behavior
(ii)
Increasing the Darwinian fitness
of relatives therefore can serve to increase the Darwinian fitness associated
with cooperative behavior
(c)
Note that key to kin selection is the ability to distinguish
non-relatives from relatives, either by recognition of some kind or via
correlates such as when relatively non-mobile individuals tend to be more
closely related to individuals who are near to them than they are to
individuals who are a greater distance from them
(d)
Kin selection essentially is cooperative behavior among kin (relatives)
resulting in greater Darwinian fitness for these relatives in comparison to
groups that do not mutually cooperate; the basis of kin selection is that
relatives share genes and therefore that enhancing the fitness of a relative to
some degree is equivalent to enhancing ones own Darwinian fitness (and, in
particular, it enhances the inclusive fitness associated with ones
genes/alleles)
(e)
(f)
[kin selection (Google Search)]
[index]
(a)
Inclusive fitness is the idea that the fitness associated with an
individual's genes is a function not just of the Darwinian fitness of the individual, but
additionally the Darwinian fitness associated with the same alleles found in
relatives
(b)
Thus, as far as your genes are concerned, your survival (and consequent
reproduction) is no more important than the survival of two full siblings
(i.e., brother or sister; with each you share half of your genes) or eight
first cousins (with each you share 1/8 of your genes); note that we are
implicitly assuming that all considered individuals have identical reproductive
potentials, e.g., are of the same age and health, etc.
(c)
[inclusive fitness (Google Search)]
[index]
(43) Coefficient of relatedness
(a)
The coefficient of relatedness is the means by which these
fractional-sharing-of-genes ideas are formalized
(b)
The coefficient of relatedness is the proportion of alleles in two
individuals that are identical by decent (the calculation of which can get
messy if inbreeding has occurred)
(i)
For example, half of your genes came from your mom and, on average,
each of your siblings shares half of these genes (since the same is true for
your father, one-half * one-half + one-half * one-half = one-half, i.e., you
share half of your genes with each full sibling)
(c)
[coefficient of relatedness
(Google Search)]
[index]
(a)
Reciprocal altruism is a means by which cooperative behavior can evolve
even between non-relatives
(b)
In reciprocal altruism, one individual performs a cooperative act in
the (evolutionary) hope that individual who is the recipient of the act will
cooperate in return
(c)
Reciprocal altruism likely requires a means by which individuals can
distinguish reciprocators from those who refuse to cooperate in return
(d)
[reciprocal altruism,
prisoner's dilemma
(Google Search)]
[prison project home page (site dedicated to the
iterated prisoner’s dilemma, a metaphor for the evolution of cooperation via, particularly,
reciprocal altruism) (LifL)] [index]
(a)
Group selection is a means by which cooperative behavior
might evolve, though chances are that in the real world it makes little
contribution except, perhaps, in the evolution of culturally learned behavior
that is cooperative
(b)
The basic idea is that two groups are competing either over resources
or directly fighting against each other; if in one group individuals cooperate
whereas in the other they do not, then the overall fitness of the cooperating
group will exceed that of the non-cooperating group, thus driving the latter,
along with its non-cooperative behavior, to extinction
(c)
For example, humans even within large groups are very willing to put
aside differences to fight against a common enemy
(i)
(which is why no change of significance is ever achieved by a
government except during times of crisis; the flip side of this is that
individuals who selfishly benefit from the status quo can always be expected to
fight, with gusto, for their benefit from the way things are)
(d)
[group selection (Google Search)]
[index]
(a)
Lastly, individuals can be willing to display cooperative behavior if doing so means avoiding punishment
(e.g., in human societies, as mediated by the police in human societies, or via
banishment by friends for exhibiting a particularly selfish behavior)
(b)
In evolutionary terms, however, punishment is some act by another that
decreases an individual's Darwinian fitness;
thus, cooperating to avoid a decline in Darwinian fitness is not necessarily an
unselfish act
(c)
Governments exist basically to foster altruism particularly by
punishing selfish behavior either directly (e.g., sending people to prison) or
indirectly (e.g., by rewarding selfless behavior such as by providing a break
on taxes for contributing to charity or by paying people directly to work in
the public's interest)
(d)
[avoidance of punishment
(Google Search)]
[index]
(47)
Vocabulary [index]
(b)
Altruism
(h)
Coefficient of relatedness
(j)
Courtship
(k)
Critical period
(m)
Ethology
(n)
FAP
(p)
Foraging
(q)
Generalists
(r)
Group selection
(s)
Habituation
(t)
Home range
(u)
Imprinting
(w)
Insight learning
(y)
Kin selection
(z)
Learning
(aa)
Mating behavior
(bb)
Mating systems
(cc)
Maturation
(dd)
Migration
(ee)
Monogamous
(ff)
Navigation
(hh)
Operant conditioning
(ii)
Optimal foraging
(jj)
Orientation
(kk)
Parental investment
(ll)
Piloting
(mm)
Play
(nn)
Polyandry
(oo)
Polygamous
(pp)
Polygyny
(qq)
Promiscuous
(ss)
Reciprocal altruism
(tt)
Releaser
(uu)
Rhythmic behaviors
(vv)
Search image
(ww)
Sign stimulus
(xx)
Social behavior
(yy)
Sociobiology
(zz)
Specialists
(aaa)
Taxis
(bbb)
Territoriality
(ccc)
Ultimate causation