Unit 1 Notes: Introduction to Animal Behavior

History of Animal Behavior Ethology

o The branch of biology specifically concerned with _______________________________________________

o While animals have always been a part of our world, the study of their behavior, or ethology, didn’t become popular until the 20th century

Lets take a look at the scientists who helped to develop the field of animal behavior

Aristotle Greek philosopher; 1st to systematically study animals He observed animals and then attempted to understand what those observations meant Believed that all living organisms could be organized on a ladder of

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Carl Linnaeus Swedish biologist and founder of botany Created system for classifying and naming animals

Taxonomyo System of classifying and naming animals in a way that the name indicates the

relationship between animals 7 taxonomic levels

____________________________ Most broad ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ Most specific

Binomial Nomenclature

o All animals’ scientific names are derived from Linnaeus’s taxonomic classification system

Each animal is identified, in Latin, using binomial nomenclature (two-part naming system)

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____________________________________________________________________________________ Ex: Cat Felis catus

Lion Panthera leo Tiger Panthera tigris

Lamarck Provided 1st systematic theory of animal evolution

o _____________________________________________________________________________________________________ Organisms inherit the characteristics that their parents had acquired with

experiences in their lifetime Ex: Giraffes developed long necks because their ancestors stretched their

necks upward to reach leaves on tall trees

Charles Darwin Presented the theory that evolution of animals (including humans) was due to

______________________________________________________ Before Darwin people, and scientists, had an ____________________________________________________ view of

the worldo Humans were at the center of the universe and superior to animals

He believed that ALL animals were related to each other through a common ancestor

George Romanes

Credited with the idea that animal behavior should be studied for the purpose of understanding the behavior of human beings

Used the _______________________________________________________________o Obtained facts and descriptions of animal behavior to try and infer what the animal’s state

of mind was at the time of the behavior, assuming that all animals have similar states of mind

Ex: If an animal was presented with a stimulus and runs away, what might we think that animal is experiencing? Why?

This method is no longer accepted in the field of animal behavior because

it_________________________________________________________ the behavioro What does this mean?

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What about the behaviors that certain animals always exhibit?

__________________________________________________________o Innate behaviors

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o Complex behavior that is typically initiated by a stimulus, but is completed until the behavior is finished, even if the stimulus is removed

Ex: Baby bird opening its mouth wide when its parent returns to the nest Ex: A bird placing food in the bright red mouths of its young

Proximate and Ultimate Causes

There are two causes to an animal’s behavior1. Ultimate Causes

o Also called __________________________________________________________________

o Answers _________________________ questions regarding an animal’s behavior

o Looks at _______________________________________________________________________________ behavior Causes that help the survival of the species

2. Proximal Causeso Answers ____________________________________ questions regarding animal behavior

o Looks at _________________________________________________________________of behavior and HOW immediate physiological or environmental stimuli can directly cause a certain behavior

Example 1:o Horns in dung beetles

Horns may be on males only, females only, or both males and females Ultimate causes:

o Use by males to battle other maleso Used to free themselves from the pupae casingo Used by females as a signal of fitness (larger horns=greater fitness)

Proximate causes:o Beetle horns arise due to hormonal signalso Horns develop due to an increase in hemolymph pressure in the

exoskeleton

Example 2:o Jellyfish migration

Jellyfish move upward to the surface of the ocean during the day and into deeper waters at night

Ultimate causes:o They eat photosynthetic organisms, which require sunlight to live,

thus their primary food source is found closer to the surface of the water

Proximate causes:o When the sun rises, they switch from a random pulsing of their bells

to a more clear, organized, pulsing, which further directs them to the sunlight

Explain each of the following human behaviors in terms of proximate AND ultimate causeso Walking and running

o Eating

o Flirting with a boy or girl

Perspectives of Ethology

Perspectives– ________________________________________________________________________________________________o Each perspective asks different questions and has different methods of answering them

ALL study behavior and consequences to behavior Perspectives of Ethology:

o __________________________________________________________________________

o __________________________________________________________________________

o __________________________________________________________________________

o __________________________________________________________________________

Developmental Perspective ________________________________________________________________________________________________________________

o _____________________________________________________________—expression of genetic potential due to interactions with the environment

As an animal experiences and learns new things, it may change its behavior as a result

o _____________________________________________________________– the “turning on” of genes as a result of interactions with the environment

As an animal interacts with something in its environment, genes may be activated that could alter the animal’s behavior

Ecological Perspective ________________________________________________________________________________________________________________

o Environment– ecosystem, time, and space Climatic variables such as moisture and temperature, other organisms– predators,

prey, companions, mates, etc. can affect an animals behavior

Physiological Perspective

What are the biological needs of the organism and how does this affect behavior?

o The __________________________________________________________________________________________________ of an animal can have a significant impact on behavior

Hormones and pheromones Neurons—send and interpret messages from the environment to the brain Senses– smell, taste, hearing, sight, touch

Evolutionary Perspective _________________________________________________________________________________________________________________

_________________________________________________________________________________________________________________o Biological variations affect changes in traits and characteristics of animals

________________________________________________________—physical description of organism

________________________________________________________—genetic make up of an organism

________________________________________________________– change in genetic sequence resulting in a different genotype and possibly phenotype of an organism

________________________________________________________—biological unit of inheritance

________________________________________________________—cultural unit of inheritance

________________________________________________________—number of individuals that can successfully reproduce and pass genetic information on to the next generation

Research Methods There are multiple methods that ethologists can use when conducting research

1. Observational methods2. Experimental methods3. Correlational methods4. Comparative methods5. Cost-benefit analysis

Observational Method

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_________________________________________________________________________________________________________________o Includes watching, listening, videotaping, filming, photographing, and drawing what you

observe.

Ethogram _________________________________________________________________________________________________________________

Type of Behavior Behavior Description of BehaviorSolitary Groom self Animal engages in washing or smoothing its own fur or

hair using tongue or forelimbs

Sleep Animal assumes species-specific position for sleep, stays in one place and is not alert to environmental changes

Rest Animal stays in one place but may be roused easily by environmental changes

Locomote Animal moves from place to place

Food Related Eat Animal consumes food it finds in its environment

Look for Food Animal searches the environment for food items

Drink Animal consumes water or other liquids found in its environment

Experimental Method Involves manipulating the independent variable and measuring its effect on the dependent

variable while trying to hold other factors constant

o Independent variables: ______________________________________________________________________________

o Dependent variables: ________________________________________________________________________________

Method of Isolationo One group of animals is deprived (or isolated from) an experience while the other receives

it Ex: White footed deer mice

Correlational Method _________________________________________________________________________________________________________________

o Unlike in an experiment, NOTHING is manipulated by the researchero A correlation may suggest a possible causation, but only experiments can verify that a

causation actually occurs. Ex: as air temperature increases animal activity increases

Comparative Method _________________________________________________________________________________________________________________

_________________________________________________________________________________________________________________o Ex: Ungulates in Africa– each is an antelope species but they all look and behave very

differently

Cost-Benefit Analysis _________________________________________________________________________________________________________________

_________________________________________________________________________________________________________________o It is assumed that the animal will behave in a way that maximizes benefits and minimizes

costs Ex: Gulls that remove the shells from their new hatchlings when they are 1 hour old

How are animals protected by researchers?

________________________________________________________________o Reflects an interest in minimizing the pain and suffering of animals and a concern for their

care by researchers in terms of: Caging Lighting Food and water Exercise

__________________________________________________________________o Involves the idea that animals have rights similar to human rights and therefore should

have protection under the law

Darwin’s Theory of Evolution

1. _______________________________________________________________________ variation in both behavior and physical characteristics exists between individuals in a species

2. _______________________________________________________________________ Biologically relevant information is passed from one generation to the next

3. _______________________________________________________________________ In order for individuals to survive and pass their traits onto the next generation, they must be

able to adapt to their environment

4. _______________________________________________________________________ Nature will tend to select for the survival of those animals that best cope with whatever

situations confront them in their environment

Evidence of Evolution

1. ___________________________________________________________ Large scale evolutionary changes are found in the fossil record

o When we look back at the bones of animals we see a systematic change in their anatomy

Ex: fossil evidence traces all mammals back to a shrew-like organism

2. __________________________________________________________

o Particular organisms are found in particular environments and not others. This implies that the environment plays a role in selecting which species can live there

o Ex: polar bears, not black bears, are found in the arctic

3. __________________________________________________________________________________o Similarities in species exist due to having a common ancestor

Ex: ants, bees, beetles and butterflies all look different, but are all insects because they have 6 legs, hard exoskeletons and wings

4. _________________________________________________________________o There is evidence of evolution in the imperfections that many organisms have in the

form of useless organs or anatomical structures Ex: appendix, all mammals having gills during embryonic development, hip

bones in snakes

Isolation and Speciation Darwin’s theory of evolution allowed us to further understand the process of speciation, or how

new species formo __________________________________________________________________________

Most important factor leading to speciation Occurs when one species begins to diverge into two separate populations when

members become isolated by environmental circumstances (earthquakes, separating continents, storms etc.)

o ____________________________________________________________________________ Process that occurs when a species spreads to new habitats and its offspring

evolve into different species in response to habitat differences

Types of Selection Evolutionary forms of selection:

o ________________________________________________ An extreme phenotype is favored over all other phenotypes, causing the

allele frequency to shift over time in the direction of that phenotype

o _________________________________________________ Extreme values of a trait are favored over the intermediary ones causing

the single group to diverge into 2 very different groups

o __________________________________________________ Favors the “average” individual, not those who are above or below

average

Directional Selection An extreme phenotype is favored over all other phenotypes, causing the allele frequency to shift

over time in the direction of that phenotypeo Ex: Long necks in giraffes OR coloration in peppered moths

Causes the population to move in one direction toward a particular phenotype

Disruptive Selection Extreme values of a trait are favored over the intermediary ones causing the single group to

diverge into 2 very different groups

Also called ____________________________________________________________________

Favors either extreme, but nothing in the middle Occurs in areas that provide different resources

o Ex: Galapagos finches have a variety of food choices Small birds feed on small seeds and large birds feed on large seeds Natural selection favors both large and small birds, not medium sized

birds who would compete for both resources

Stabilizing Selection Favors the “average” individual, not those who are above or below average

Also called ____________________________________________________________________o Ex: Sizes in lizards—large lizards may be subject to predation, small lizards have a hard

time defending territories, natural selection favors the average sized lizard

Sexual Selection Process whereby nature selects different traits and behaviors in males and females because

different characteristics _________________________________________________________________________________________________________________

o Sexual selection can take the mode of directional, disruptive, or stabilizing selectiono Behaviors involved:

Courtship Mating rituals Parenting

Mutations and Evolution Mutations

o _________________________________________________________________________________________________________ sometimes due to radiation, chemicals, or other unknown factors

o NOT ALL MUTATIONS ARE BAD Most are meaningless or harmless and do not change the appearance or behavior of

the animal…BUT occasionally they can cause new physical characteristics or structures in an animal and may also lead to changes in its behavior

Some of these mutations may lead the animal to be more adapted and fit in their environment

Gene flow and Evolution Gene flow

o Alleles may move into or out of a population due to the movement of breeding individuals from one geographic area to another

oo Can change the ____________________________________ of specific alleles or introduce ______________

alleles into a population

o An _________________________________________in gene flow causes a _________________________________in genetic variation between populations, making them more similar to one another

Genetic Drift and Evolution Genetic drift

o Changes in the gene pool that are attributed to _________________________________________

o Mostly impacts _____________________________________________________________________________ An allele can quickly disappear if by chance those individuals who possess it are

unable to reproduce

Bottleneck effect

Genes and Behavioro The nature vs nurture question

How can we determine if a behavior is due to genes or the environment?

_______________________________________________o After several generations animals will be almost genetically identical

allowing scientists to manipulate their environment and observe their behaviors

________________________________________________o Raising genetically identical organisms in different environments and

comparing their behaviors

Do you think these types of studies can be done with any species of organism? Why?