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Chapter 52
Behavioral Biology
Innate behavior

Some behaviors are
“preprogrammed”
into the nervous
system
 Triggered by a
stimulus - can vary
 Other examples??
 Proximate
causation defines
how something works…
 Ultimate causation discusses
why it works!
Behavioral genetics

Take the “rats in a maze”…
– Some learn faster than others to get the
cheese
– Genetic superiority??

Can also witness differences between
identical twins!
– Some say nature over nurture, but what
about twins separated at birth who lead
“parallel” lives?
– Creepy??
Some behavior is learned…

Touch a hot flame, learn to stay away from
fire!
 Salivation at the sound of a bell…example of
_____?
 Trial and error to get a desired result…
 Some are simply due to the biology of the
animal.
– Now have I.D.ed specific genes that may govern
behavior
Learning influences behavior

When we learn, we change our behavior to
reflect that learning
 Some are not stimulated (habitual) and some
require an association between a stimulus
and a response. Ex: Pavlov
 Instinctual learning - biologically influenced goes back to evolution…
– Burying seeds and remembering where to find
them = larger memory center in the brain of those
animals who exhibit this behavior
Parent-Offspring interactions

Most behavioral biologists recognize that
behavior is both learned and genetic
 We imprint on our parents to a degree - this
may influence some decisions later in life
 Other animals may imprint on the first thing
they see!
 Genetically, animals may be attuned to
certain songs, sound, or smells that guide
them to the correct species:
– Ex: Cuckoos - have pre-programmed songs for
their species even though they are raised by
others
Migratory Behavior



Taxis - moving toward
or away from a stimulus
ex: moths to light
Kineses - changing
activity in response to
an increasing stimulus
Animals who migrate
use the stars, sun,
landmarks, and
magnetic fields to
navigate Ex:
monarchs, geese, sea
turtles
– Others?
Communication
Some species
have distinct
sounds
 Pheremones
 Levels of
specificity - to
make the
individual stand
out

Social animals sometimes have designated
individuals to carry out specific jobs
 ~ honeybees - guards, drones, queen
 ~ other examples?
 Language among higher animals - primates in
particular - help convey meaning to others in the
group

Evolution shapes behavior

Behavioral ecology - study of how natural
selection shapes behavior
 ~ after a baby bird hatches, the parents
often remove the shell to reduce predators
seeing the broken shell and eating the
offspring - is adaptive
 Is all behavior adaptive?
– Not necessarily…can be caused by genetic drift,
gene flow, or consequences of conscious
selection
– Could also be past adaptations that evolved and
are no longer useful!
Examples of behaviors…

Foraging - looking for food and weighing the
cost of finding it with the amount of reward at
the end

~ must be energy efficient to be productive
- max input per foraging time
 Territorial - defend your ground against
predators and intrusion!
 Reproductive Strategies - benefit of choosing
this mate over that one…
– Parental investment - each sex makes a different
contribution to making and rearing offspring
– Vary greatly among species!
Evolution of social behavior?



Altruistic - benfits one
while costing the one
who is helping
* Seen in lions - all cubs
nurse from more than
just the mother
Reciprocity - “you
scratch my back and I’ll
scratch yours”

Social animals are more likely to
behave in a way to protect their kin if
they have a higher number of related
members in the group
– ~ ie - if a mother has many children in a
group, she will act to protect them more
than if she was a “aunt” to those children
Haplodiploidy
Bees have distinct roles
within the social group
~ members are of differing
sizes and abilities
~ do not stray from their
roles
~ males are haploid,
females diploid
~ eusocial system


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Vertebrate systems are
less organized and are
less altruistic
Usually kin selected
altruism
So which is evolutionarily
more advanced???
Still up for debate!