Behavior

What is behavior?•Behavior can be considered any response to a stimulus.

•More broadly behavior can be considered what an organism does and how it does it.

•Niko Tinbergen defined behavior as “the total movements made by the intact animal.”

Bacterial “behavior”: Quorum Sensing•Aliivibrio vischeri is a bacteria that can

either be found free living in the ocean, or within the mantle of the Hawaiian Bobtail Squid.

•When large numbers of vischeri are concentrated together within the mantle of the squid, they glow (bioluminescence)

•Free living vischeri do not glow.

Tropism – Plant “behavior”•Growth in a direction either towards

(positive) or away from (negative) a stimulus

•Photo- light•Gravi- gravity•Chemo- chemicals•Hydro – water•Thigmo – Touch or contact

Animal Behavior•What an animal does and how it does it•Includes both motor components and

concepts such as learning and memory

Every behavior has both an ultimate and a proximate cause•Proximate causes – the stimulus that activates a behavior

•Ultimate causes – ask why a behavior originated, what adaptive benefit does it produce?

Nature or Nurture?•Which determines behavior, an

organism’s genes or an organism’s environment?

Nature or Nurture?

Nature or nurture?•Both•All behavior is at least in part controlled

by genetics and at least in part controlled by the environment an organism finds itself in.

•A better question may be to what degree is a trait genetic or to what degree is a trait environmental?

Instinct•Instincts are behaviors that are considered developmentally fixed

•All individuals exhibit the same behavior despite environmental differences

Fixed Action Patterns•A behavioral act, initially by a sign stimulus, that is unchangeable.

Supernormal stimulus

Code breaking

The Four Questions•Proposed by Niko Tinbergen •1. What are the stimuli that elicit the response? (Mechanism)

•2. How does the behavior change over time and how is behavior affected by environment? (Development/Ontogeny)

•3. How does the behavior impact survival and reproduction? (Adaptation)

•4. How does the behavior compare with that of similar species? (Phylogeny)

The Four Questions•1. What are the stimuli that elicit the response? (Mechanism)

•2. How does the behavior change over time and how is behavior affected by environment? (Development/Ontogeny)

•3. How does the behavior impact survival and reproduction? (Adaptation)

•4. How does the behavior compare with that of similar species? (Phylogeny)

Learning•Modification of behavior from experience

•Learning can affect the efficacy of instincts

Maturation•Maturation refers to refinement of an

instinct with age, not with learning.

Habituation•Simple learning•An organism stops responding to a

stimulus if disturbed repeatedly with no payoff.