New Caledonian crows have the capacity for

abstract thought (use one tool to access anohter tool that will help them reach food)

behavior (evolves)

internally generated response to external stimuli

• can evolve via natural selection due to effect on fitness
• vary from individual to individual
• variation at least partly genetic

Fox experiment

docility in foxes can be a learned behavior through specific breeding [genes influence behavio]

• Response to artificial selection extremely rapid
• QTL analysis shows heritable behavior with fox pop. (aggressive behavior correlated with neural crest cells)

Genetic influence on behavior

1. Moment-to-moment
2. Development
3. Selection

Basically, behavior can be artificially selected for in animals

Tinbergen

laid foundation for study of behavior from evolutionary perspective, four questions:

1. How does it work?
2. How does it develop?
3. What is its adaptive value?
4. How did it evolve?

juvenile stickleback sfrom freshwater lakes were

less social, more aggressive towards conspecifics, and less likely to school

under gentic ontrol, oldfield mice produce

distinctive burrow

Behavioral ecology

science that explores the relationship between behavior, ecology, and evolution -> highlights significance of animal actions

Proximate Causations

explains biological functions via immediate physiological/environmental factors (how behavior is elicited)

Ultimate Causations

explains traits via evolutionary forces acting on them

Identify behavior in organisms without brains (why particular behaviors evolved)

Cellular slime mold (Dictyostelium discoides)

organism without brains can behave in complex ways

Cope with starvation -> cells join to form a “slug” -> produce spores, but die in formation process

Plants (brainless organism)

• Venus fly traps: leaves shut to capture insects
• Australian sundews: catapult mechanism to trap insects on sticky “tentacles”

With Brains

use neurons to control behavior

Voltage spikes travel down neuron, triggers release of neurotransmitters at synapse -> triggers activity in neighboring neurons

Early nervous system

Alalcomenaeus (520 mya, very similar nervous system to modern relative)

Nervous system evolved via gene co-option

Agreement

genes for cell-to-cell communication co-opted

Uncertain

if earliest multicell animals had nervous system or if it can from more derived animals

Sponges lack nervous systems, however

make homologs of proteins found in neurons

Two hypotheses via origins of nervous system

ctenophores w/ pivotal role

1. Nervous system evolved in common ancestor, but lost in sponges
2. Nervous system evolved in ctenophores (sponge ancestor?) independently (more evidence supports this one)

Innate behavior

behavior that is genetically hardwired in organism, can be performed in response to cue without prior experience

Synaptic plasticity

ability to strengthen and weaken over time via increase/decrease in activity

[ex. Dendritic spins grow from learning behaviors]

Benefits of living in a group

• Increased vigilance
• Dilution effect (safety in numbers)
• Enhanced defense capability
• Cooperative foraging/hunting
• Improved defense of critical resources

Costs of living in a group

• Increased visibility to predators
• Increased competition for food
• Increased competition for mates
• Decreased certainty of paternity/maternity (polygamy/cheating more often)
• Increased transmission of disease/parasites

Tidbit

wild dogs, unlike orcas, do NOT have group size limit, success usually stays the same/increases as group size increases

Inclusive fitness

direct fitness + indirect fitness (WILL BE FINAL QUESTION RELATED TO THIS)

Direct fitness

organism’s own success in transferring alleles to future generations

Indirect fitness

reproductive success of other individuals carrying same allele

also explains altruism via potential to pass on same alleles to offspring

dilution effect

safety innumbers that arises through swamping the foraging capacity of local predators

Kin selection

selection from indirect benefits of helping relatives

Inclusive selection leads to kin selection via accounting for both your own fitness and the fitness of those related to you, coefficient of relatedness w/ greater chance of success of carrying down similar alleles

HAMILTON’S RULE

describes when altruism is favored

rB>C

Female ground squirrels (kin selection)

do not venture far from birthplace (unlike males), more likely to give warning calls

If hawk seen, net benefit of alarm (warns relatives), but danger to squirrel who made call

White-fronted bee-eaters

during drought, offspring stay with parents and help raise siblings

Giant water bugs

males keep eggs on back, aerate via coming to water surface (very risky)

Certainty of paternity via only accepting eggs after mating with same female several times

Male side-blotched lizards

3 different behaviors, varying frequency from year to year based on mating success (types oscillate in frequency over time) ornage, blue, yellow

Bred flies

quickly learned to identify quinine laced bread -> fast-learning flies produced fast-learning offspring -> cost: fast-learning flies died sooner than normal flies

capacity to learn can evolve, but may come at a cost

earliest fossil evidence of brain

vertebrate development was the evolution of the brain, 530 bya Haikouichthys

vertebrate organization is

relatively conserved

Bilaterian (organisms with right and left sides) development

trend towards cephalization (concentrating scent organs into “head”)

Somatosensory cortex

senses, if function occurring inside and outside (pictures shows enlarged areas where somatosensory cortex effect is strongest) -> disgusting

Cerebellum

maintaining balance

Broca’s area

speech

Prefrontal cortex/neocortex

attention, thought, perception and episodic memory

Hypothalamus

homeostasis

Amygdala

emotional responses

As you get older your amygdala degrades, meaning that you have a less of a social filter

parts of brain vary in size depending

on vertebrate species

Complex (sometimes not understandable) animal behaviors

• Octopus “randomly” hits passing fish, no reason found, did it have a bad day?
• Chimps communicate via gestures, can identify group based on these gestures
• Dolphins wear sponges to protect rostrum (nose) during feeding