Animal behavior

Animal behavior

coordinated responses of whole living organisms to internal and external stimuli

whos TINBERGEN

one of the founders of ethology, shared Nobel prize with frisch and lorenz

• developed scientific method

• refused to work with the nazis party

ethology

study of animal behavior

three foundations

natural selection, individual learning, cultural transmission

cultural transmission

transfer of information from one individual to another through teaching or social learning

Konrad Lorenz

• birth of ethology

• pioneered studies of instinct

• concept of imprinting

• served in german army as medic

• spent 4 years as pow

• strong proponent of eugenics

eugenics

selection of desired heritable characteristics to improve future generations

von frisch

• proved that animals are also capable of abstract thought

• declared ¼ jewish by the nazis

• however go funding from nazis to grow food for them

lamarck

as organisms develop to environment it will change to environment

Ex: giraffes neck will grow to reach the taller leaves by growing a longer neck overtime

darwins book

• origins of species

• common ancestor

• environments impacting which genes continue to the next generation

sexual selection

• Depends on success of certain individuals over others of same sex in relation to propagation of species

Charles turner

• Insects use memory and cognitive processes to navigate

• First example of pavlovian conditioning in an insect

• Did all of this by himself and wasn’t support from any university

artificial selection

animal breed for specific traits

domestication

domestication

• Occurs when care and breeding is under human control, occurs over many generations

natural selection

process through which evolution can occur

effects of domestication

Pedomorphosis (neoteny) is the retention of juvenile body morphology and features into maturity

• retention of juvenile features in adult animals

increased coat colors

selected breeding

risk aversion

What is evolution

• Any change in allele(gene) frequencies in a population over time

• Change in heritable characteristics of populations over successive generations

Linear hierarchy 

each member has exactly one direct superior and one direct subordinate

genotype

 composed of genes that code for two alleles among a diversity of alleles

genetic makeup that leads to a phenotype( expressed trait)

many genes code for one trait

allele

most of the time they don’t do anything but sometimes they can result in phenotype changes

• all genetic changes are the result of allele

• You have 2 alleles of each gene 1 on each homologous chromosome 1 from each parent

Knockout

means the gent for it was removed from the animal’s genome

• knockouts can be produced naturally or artificially

Habituation

• Present a subject with a stimulus animal or their odor repeatedly with each successive exposure interest gets lower and lower

Discrimination

• In the final exposure use of a novel stimulus interest should spike

novel stimulus

a new or unfamiliar sensory input that an organism encounters for the first time

Polygenic trait

• A phenotype controlled by multiple genes. Usually complex traits like behaviors

Requirements for selection

• Inheritability of phenotype

  • genes

• Variation in a trait

  • Different alleles causing different phenotypes

• Variation of fitness benefits

  • Different phenotypes lead to different amounts of offspring

Darwinian theory 

Animals with certain traits will survive and reproduce better than others

• These traits will be more prevalent in the next generation there is evolutionary change

Resources must be limited for evolution to occur

Directional selection

For: one extreme trait 

Against: the other extreme

Stabilizing selection 

For: moderate traits

Against: both extremes

Disruptive selection 

For: both extremes 

Against: moderate traits 

4 causes of Genetic variation 

 mutation 

Gene flow ( migration)

Genetic drift (due to chance)

Selection 

mutation

-errors in dna replication that lead to change in a dna sequence 

-Chang in dns sequence may lead to a change in the resulting protein product

fitness

-an individual’s fitness is measured by its reproductive contribution to the next gene pool, its reproductive success

- if an organism survives for a long time but doesn’t reproduce it matters little its all about reproduction

group selection

• Any adaption that would improve a group survival over another group would also improve the individual's survival even if it doesn't directly benefit the individual 

• By cooperating with each other they ensure each others survival

HOWEVER

Group selection will occur only if these factors happen, group selection will never be stronger than individual selection

• Weak force 

• Only if migration is very low and group extinction rates very high 

• Group selection may exist, it just cannot counteract individual selection

Natural selection is selfish and not for the good of the species as a whole

Grandmother hypothesis

Human menopause evolved because it was evolutionarily advantageous for older women to stop reproducing and instead invest their energy in supporting the survival and well being of their grandchildren

Total oxytocin 

• Either bond to receptor or free

• Not diff in aggression

Vasopressin

• Higher in animals that are more aggressive 

oxytocin

higher in companion animals

Hormone

regulatory substance produced in an organism and transported in tissue fluids such as blood to stimulate specific cells or tissues into action

• hormone travels via bloodstream to target cells

• requires a receptor in order for the hormone to get a response

• Regulates cell reactions by affecting gene expression (often gene transcription factors)  

  
  
  

endocrine system, hormones

• The endocrine system broadcasts its hormonal messages to essentially all cells by secretion into blood and extracellular fluid.

endocrine system

• Hormone: mediator molecule released in one part of the body but regulates activity of cells in other parts

• Slower responses effects last long broader influence

Endocrine and Nervous System 

• Major communication systems in the body

 • Integrate stimuli and responses to changes in external and internal environment 

• Both are crucial to coordinated functions of highly differentiated cells, tissues and organs 

• Unlike the nervous system, the endocrine system is anatomically discontinuous

 Major endocrine glands

Hypothalamus

Thyroid gland

Pituitary gland 

Parathyroids

Adrenal glands

Pancreas

Ovary

•Neurotransmitters

substances released by neurons that are received by adjacent neurons & alter their membrane potential.

•Pheromones

substances released by an individual as scent signals for another.

How to study hormones and behavior

• Remove the gland

• Add hormone

• Measure circulation levels

• Block receptors

estradiol

• causes some sexual behaviors

• Too much estradiol eliminates sexual behavior

• Can be restored by treatment with estradiol followed by progesterone

testosterone male animals

• Testes generate sperm and release testosterone

• Castrated males do not fight or mate

• Testosterone implants restore behavior

what do longer days indicate for testosterone in animals

cue increase in testosterone as it is related to breeding season

• Different selection pressures result in modifications of the hormonal mechanisms of behavior

activational effects

• Short term reversible effects that occur in the fully developed organism (ex: alteration of transmission in neural networks that respond to certain aspects of the environment)

Organizational effects

• Long term irreversible effects on tissue differentiation and development

• these effects are permanent

• occur early in life usually just before or after birth before the brain and other tissues have matured

Organizational effects can only occur during a critical or sensitive period

• ex brain or indirectly ovary that can either directly (brain) or indirectly (ovary) influence behavior

Organizational effects are asymmetric to the sexes

• T masculinizes absence of t results in female development 

In adults steroids have?

• Short term impermanent effects

• No reorganization of neural pathways

• These effects are not restricted to critical periods

steroids in early development

• Long term alteration i.e. size or connectivity of pathways or metabolism or responsiveness of neurons to steroids 

• Oxytocin and maternal behavior in house mice

• 
  
  

  • Pre maternal mice fear pups and will attack them 

  • Oxytocin injections induce maternal behavior

Oxytocin and maternal behavior in sheep

• Stimulation of birth canal during parturition results in oxytocin release in brian

• Oxytocin injection cause non pregnant females to accept unfamiliar lambs in 30 second

• Peptide hormones generally act more rapidly than steroid hormone

News and views 

1. Looking at raccoons and if they were showing any self domestication by feeding off of human waste

2. capuchin monkey

• from scoial gorup and what effects group size changes

3. 20 minute contac with nature reduces stress hromone aka cortisol

Hormones and behavior 

• Organization activation

• In utero and parental effects

what does aromatase do

• converts testosterone to estrogen

• controls what areas will be sensitive to estrogen

what happens when tesosterone increases

• increase in aggression

• parental behavior decreases

what is stress cause by

glucocoids

what does stress do to genes

• stress turns on or off genes

• stress is turned off through negative feedback

stress is good as a safety precaution but chronic stress is always bad

what traits will females surrounded by males in uterus have (2m)

• higher testosterone

• better at competing for resources aka more aggressive

• decreased fertility and less attractive to males

• have less contact to young as opposed to 2f females

mother might be able to influence hormones that her young can be exposed to in womb

• might be controlled, might not

Human studies examining opposite sex twin adult outcomes

• Theses studies vary extremely 

• No effects found in males 

• Twinning has nearly doubled since 1980

• Female-male pairs

  • Females more likely to drop out slightly less likely to graduate, no effect on choice of STEM major

  • Less likely to be married, fewer children

challenge effect

• Transient (short) increase in testosterone occurs in response to a challenge from another male 

• Testosterone increases probability of winning a fight AND winning a fight increases the level of testosterone 

  
  
  

Winner challenge effects

• Function of transient increases in encounter in males is to increase chances of  winning a fight against another male

• More wins they have more likely they are to win future encounters

adrenal gland

releases cortisol in humans

behavior of penguins

• It appears that penguins have habituated to humans and display fewer defensive behavior in response to humans

acute stress

sudden typically short lived threaten event

chronic stress

ongoing environmental demand

• marital conflict, work stress

• can lead to slower healing

• ex:Postmenopausal women

who serve as caregivers for

chronically ill spouses

displayed higher cortisol

levels and slower wound

healing from a biopsy wound

on the arm compared to

age-matched controls

Learned Helplessness human definitions

• The acquired sense that one can no longer control the

environment, with the result that one gives up trying

learned helplessness humans Perceive negative events as:

• Stable: Caused by factors that don’t change with time

• Internal: Caused by you

• Global: Causes of one negative event apply to other

events

• Loss or perceived loss of control can result in

depression

Proximate

• immediate causes

• Mechanistic

• Developmental

• Questions about HOW behavior happens

• Focus on internal mechanisms of behavior

• 
  

ultimate

• evolutionary forces

• Questions about WHY a behavior occurs

• Deals with evolutionary value of behavior or evolutionary forces that shape

• Survival value

• Evolutionary

what are the mechanistic, developmental, survival, and evolutionary/phylogenetic inquiries of behavior

Mechanistic: how neuronal-hormonal mechanisms control animal behavior

Developmental: how genetic-developmental mechanisms influence the assembly of animal, including nervous/endocrine system

Evolutionary: how behaviors evolved over generations of a species (ex: disposable thumb in all primates)

Survival: the ways in which specific behaviors have adaptive value

information-center hypothesis

the idea that foragers can learn critical learning about the location and identity of food by interacting with others that have recently returned from foraging bouts

Learned helplessness in dogs

• Behavioral task for studying how uncontrollable outcome stress can influence later responding

• When an outcome is experienced as an uncontrollable event, an individual might not respond later when given the opportunity

Seligman method

1. Phase 1: Two groups of dogs receive shocks while strapped in hammocks

Group A had control: Lever next to nose turned off shocks (control via lever)

Group B had no control: No lever to affect shocks, but same duration of shocks as Group A

Result: learned helplessness when no control (also higher stress)

2. Phase 2: Brought into divided pen (2 compartments, separated by short barrier)

Electrified floor of one compartment 10 seconds after a buzzer rings

If dog leaps to other compartment in less than 10 seconds, they won’t get shocked

Result: learned helplessness if no individual control over getting shocked

Learned helplessness: after training even if there is a lever or a way to escape the stressor the animal does not act

can dogs get depression

yes

anhedonia

chronic mild stress in rats decreases sucrose intake

what happened in forced swim test when Anti-depressant fluoxetine (increases serotonin) was added

decreases immobility

increases swimming

what is separation anxiety reduced with

antidepressants for example fluoxetine

news and view covid

• Effect of covid and the change to human behavior

• Lot more animals move around during covid

• Mammals go nocturnal in bid to avoid humans 

learning

durable modification of behavior in response to information acquired through specific experiences

benefits of learning

the animal benefits from experiences so that its behavior is better suited to environmental conditions