ANS104 - Midterm 1

what is fitness?

how well the traits an organism possesses enable it to leave behind its genes under current environmental conditions

how is fitness determined?

an organisms ability to survive to reproductive age and reproduce

how does effective interaction promote fitness?

how well an animal uses its behavioral repertoire to survive long enough to reach sexual maturity and to reproduce

what must an animal to do to survive?

• explore/acquire information

• find food

• find shelter

• avoid being killed

• communicate

• negotiate social interactions

what must an animal do to reproduce?

• explore/acquire information

• find mates

• provide for young

• communicate

• negotiate social interactions

how does an animal choose which behavior to perform?

• weigh the costs and benefits to fitness

• evaluate tradeoffs

what is domestication?

• the process of adaptation to humans and captive environments

• result of interplay between genetic changes across generations and environmental stimulation and experiences during animal development

is it possible for an animal to not experience domestication within its lifetime?

yes

when did the first wave of domestication occur? what species were domesticated?

• 8000-15000 years ago

• traditional agricultural species, dogs, cats

when did the second wave of domestication occur? what species were domesticated?

• within the last 100 years

• new meat producers, lab animals, fur animals

what shapes animal behavior in the wild?

• forces of evolution: natural selection, random drift, mutation, gene fow

• natural selection

• maximizing fitness and favoring traits

what shapes animal behavior in domesticated/captive animals?

• same forces of evolution, but in captivity

• relaxation of natural selection

• artificial selection

captivity is a…

novel environmental condition

fitness in captivity is made up of…

survival and reproduction in captivity

when natural selection becomes relaxed, expression of traits in the population can…

• stay the same

• shift in frequency

• become more variable through the population

what is anthropogenenic?

generated by humans

what are the three selection pressures in captivity?

• natural selection in captivity

• relaxation of natural selection

• artificial selection

what is natural selection in captivity?

animals better adapted to the captive environment have better survival and produce more offspringwh

what is relaxation of natural selection?

environmental modification/change that eliminates or dramatically weakens selection pressures that were formerly important for the maintenance of a particular trait

what is artificial selection?

selective breeding for particular traits; controlled by humans and does not occur naturally

what are the three results of domestication?

1. domestication does not change motor patterns, but it can change when and how often animals perform a behavior

2. domestication changes the quantity (threshold/amount), not its quality (motor patterns)

3. for the most part, no new behaviors are created

what is a threshold?

stimulation required to elicit a specific response

what is contrafreeloading?

behavior where an animal chooses to work for food even when identical food can be obtained w/o any effort

what are some common physical outcomes of domestication?

• piebald coloring

• wavy or curly hair

• rolled tails

• floppy ears

• shortened tails

• changes in reproductive cycles

behaviors can be performed across a spectrum from….

rigid to highly flexible

fitness equals…

survival + reproduction

tamness is a result of…

training and environment. not enough time for artificial selection to have an effect

for behaviors to evolve, there must be…

a heritable component to behavior (for the most part)

behavior is a…

gene product

what are the heritable components of behavior?

• selective breeding

• hybridization

what is the assumption for selective breeding?

• if the frequency in a trait in a population can be shifted over generations by choose to breed individuals with or without the trait

• correlations between genes and trait

what are the four potential outcomes of hybridization if a behavioral trait a genetic component?

1. F1 pop. expresses the trait intermediately

2. F1 pop. resembles one parent strain and not the other

3. F1 pop. expresses the trait more vigorously than either parent

4. no correlation = F1 pop expresses the trait randomly

what is pleitropy?

a single gene produces multiple genes/phenotypes/behaviors

what are the two different faces of social behavior?

• social tolerance

• cooperation

what is social tolerance?

the likelihood individuals will remain in close proximity to one another w/o expressing aggression

what is cooperation?

requires social tolerance, individual recognition, fairly strong bonds, and communication

what are two costs of being social?

1. more likely to be exposed to parasites and diseases

2. your group is more conspicuous and easier for prey/predators to notice you

what are four benefits of being social?

1. you can gain access to better and greater variety of food

2. disgust responses can provide useful information about food quality

3. you’re less vulnerable to predators

4. you can get help with a variety of tasks

what is the dilution effect?

chance of an individual being detected goes down in a larger group

heritable behaviors and traits can be shaped by their…

environments

what are the two types of social organization?

1. dominance hierarchy

2. territoriality

what is linear dominance hierarchy?

• more common

• seen in smaller groups

• usually more stable

• typically linear (variations exist)

what is despotic dominance hierarchy?

• not common

• observed when territorial individuals found in high density situations

• one individual is dominant over ALL others in ALL situations

what is territoritality?

geographical area maintained to exclusion of others

wildtype/ancestral social organization will influence…

how a species responds to social situations in captivity

what are the three prerequisites for maintaining stability in a hierarchy?

1. individual recognition

2. means for reinforcing relative status

3. integrity of group composition

what is altricical?

• born offspring that needs nourishment

• less developed

• sensory systems are not fully functional

• may be dependent on mother for warmth + food

what is precocial?

• mature before its time, more developed

• functional sensory system

• able to move on its own

• may be able to forage on its own

what is parity?

having borne offspringwh

what is nulliparous?

never having offspring

what is primiparous?

1st time having offspring

what is multiparous

having borne offspring more than once

what are the four parts that make up maternal care?

1. nesting

2. responsiveness

3. discrimination

4. termination

why care for offspring?

• all about maximizing fitness

• need to produce as many surviving offspring as you can

direct care immediately helps offspring by…

provisioning (lactation/nursing, feeding, thermoregulation)

indirect care helps…

• offspring survive in the long run

• protection (defending nest sites, keep predators away)

what are the two things parents that can breed more than once must do?

1. survive from one breeding to the next

2. successfully reproduce from one breeding to the next

what are the trade-offs for prioritizing the mothers fitness?

maximize lifetime reproductive fitness success, not just one kid/brood

what are the trade-offs for prioritizing the offsprings fitness?

maximize survival, use maternal resources to grow, set up future ability to reproduce, take maternal resources while you can

what is nesting characterized by?

• separation from others

• seeking protection

• creating means to provide warmth, depending on need

what is responsiveness characterized by?

• heightened behavioral response to young

• willingness to interact w/ stimuli that otherwise might not be attractive

what is a sensitive period?

a discrete window of time which a specific behavior is acquired

how does the sensitive period begin and end with the mother-offspring bond?

• begins with an increase in responsiveness to all young

• ends with individual recognition and discrimination of offspring by mother

how to does the mother respond to the placenta/amniotic fluid during the sensitive period?

both are highly attractive; stimulates grooming and licking of the neonate

how to does the mother respond to the placenta/amniotic fluid after the sensitive period?

amniotic fluid and placenta become reuplsive

how long does the sensitive period last in cattle?

less than 5 hours

how long does the sensitive period last in sheep?

less than 8 hours

how long does the sensitive period last in primiparous goats?

less than 2 hours

how long does the sensitive period last in multiparous goats?

less than 3 hours

what is discrimination characterized by?

• being able to recognize own young and tell them apart from others

• relies on sensory info like small and sound so it can indicate offspring’s level of need

what is weaning?

termination of lactation and/or provisioning of food

when does weaning occur in cattle in nature?

7-14 months old

when are beef calves weaned on ranches?

6 months