Chapter 12

Behavior

Introduction

• Observing behavior has is nearly as old as behavior itself.

• Behavior is defined as any action that is observable and describable (this varies from individual to individual).

• The scientific study of behavior is called ethology.

• All behavior is thought to have a genetic component, even aspects of sexual behavior (mating, reproducing, care of young).

• How does behavior effect our daily lives? Let’s find out, shall we?

How Do Genetics Influence Behavior?

• Genetics actually play a decisive function in our daily actions.

• In several animal studies it has been observed that behavior is also triggered by visual cues and hormones (ELH and snails & courtship rituals in Ring Doves, Mader).

Courting

C

Copulation

Nest Building

Feeding Crop Milk

Developing Behavior

• We might all agree that behavior has a genetic component.

• What about experiences? Do they shape behavior too?

• Of course they do! Experiences exhibit powerful sometimes life long influences on behavior.

• This change in behavior brought about by experience is called learning.

Behavioral Development

Other Aspects of Learning

• Let’s go one more step…How about instincts? Rewards?

• In everyday life you are operantly conditioned. You generally associate a stronger response to certain stimuli. (In actuality, you might be a dog merely learning more complex tricks.)

• Imprinting is another common behavioral aspect in animals. Basically, associating your actions with the first thing that moves once you enter the world...

• Spalding, Lorenz, and Hess have all studied this phenomenon in waterfowl.

• Although this suggests a social interaction component to behaviors; fortunately for us, imprinting doesn’t occur in humans.

• Imagine waking up to find you wanted to waddle, quack, and preen??

Silence, Sound, Social

Singing behavior in birds is a very social behavior. Male birds will learn to sing(even another species’ song) when they are exposed to the right stimulus at the correct time. However, given a teacher, they will sing what the teacher sings nomatter what time they are taught!

Culture

• Our customs, beliefs and traditions shape behavior nearly from birth.

• Language and learning help children define who they are and how they fit into society.

• Like other traits, culture evolves because individuals involved in the culture leave more offspring than those that are not. (Why is incest frowned upon?)

• Division of labor also falls into this category.

Sexual Selection

• Sexual selection, adaptive changes in males and females which ultimately lead to finding a mate, is an interesting topic for several reasons.

• It usually breeds competitive males and choosey females.

“Not tonight baby…yadda, yadda, yadda.”

Female Choice

• Yes, unless you “reach in and grab one…,” it’s predominantly female choice.

• Either by good genes, or by runaway selection.

• “But Dr. K., no one said anything about my dress code, or eloping!!”

• Wrong genes, wrong method…and a truly bad attempt at humor.

Good Genes

• In this case, females choose a male based on the traits that improve survival of offspring.

• Any examples? You tell me…

• Bower birds with more blue feathers and aggressive behavior attract more females. Is aggression good, or is blue just pretty?

Run-away Selection

• Male Raggiana birds (Birds of Paradise) and Peacock males have it all! Good looks, big tails feathers, elaborate plumage, compared to more conservative appearing female.

• This sexual dimorphism results from female choice as well. Females choose males with exaggerated traits.

• Why? Fitness, overall health, more resources?

Dominant males mate more often.

Even in humans.

Although males are seen asdominant here, females alsoestablish dominanceheirarchies.

In these cases the alpha pair have the most access toresources and therefore a greater likelihood of reproductive succes.

TerritorialityAnimals also display, defend (die) for real estate.

Territories=resources=females=reproductive success.

Animals also display, defend (die) for real estate.

Territories=resources=females=reproductive success.

Do Humans Compete?

• Is the Pope Catholic?? • Human males are physically larger and stronger on

average, are more able to mate (sperm’s cheap), and live 7 years less than females.

• There behavior tends to reflect these facts.

• Female choice still applies (how)?

Male Choice

• Do human males ever get to choose anything?

• Yes. (Finally!)

• Men prefer women with curves (hour-glass figure). Kate Moss, Paris Hilton, etc. are actually counter intuitive when it comes to male choice. Anna Nicole’s build is preferred…believe it or not!

• Wider hips and larger breasts are directly correlated with successful child bearing. (Sir Mix-a-Lot was right!)

Other Communication…

Tactile Communication Pheromones

Also, sound, taste…

Altruism?? Babysitting your brother’s kids?

If you want maximum fitness, yes. Rem: Your 50-75% genetically related to sibs and much less so to mom and dad.

Final Thoughts

• Humans engage in MANY behaviors which are directly linked to sexual reproduction.

• Reproductive fitness is important, but in our society, deceit actually plays a role too. This is also true in animals, but to a lesser exent.

• We may be more alike animals than unlike…