Biology 484 – Ethology

Chapter 3b – The Development of Behavior: Genetic and Environmental Factors

Spatial learning by chickadees

Spatial learning is learning about location and position. In this study, the bird shows it is able to display this learning by searching far longer in sites where the bird had stored food.

Differences within a species in learned behavior

The environment plays a significant role in how well learning occurs.

Here chickadees in the harsh environment of Alaska show better memory of where stored food is located than do the same species in Colorado.

Nests of Polistes paper wasps contain odors that adhere to the bodies of the wasps

The odor cues that remain in the home next of these wasps are unique to other homes of the same species. This odor is recognized because of the larvae being closely associated with the nest and walls. These odor cues allow nest mates to recognize each other in adulthood.

Different wintering sites of blackcap warblers

Different populations of this bird choose distinctly different wintering sites.

Notice how SOME birds actually winter in the location where others exist in the summer.

Thought Question: How do you explain these differences, especially the OVERLAP of areas in the SAME SPECIES?

These data show flight points that were observed in the birds from each Summer locale. Notice the clustering of the directionality.

These data are not in the text, but show what is called “circular orientation data” that is examined through the use of “Circular Statistics” a special category of statistics.

When animals are collected and taken to a different location, you see that each population maintains a flight path that is unique to its Summer group.

Funnel cage for recording the migratory orientation of captive birds

Here is an example of an in-lab method to study orientation behavior. The same sort of situation can be used to study ANY orienting animal.

These type of data require “Circular Statistics” for analysis.

Whole fields of study IN statistics are devoted to analysis of directionality. The cutting edge nature of the statistical tools used for analysis of orientation data, makes it more challenging for biologists who want to enter the field of study.

Differences in the migratory behavior of two closely related birds

Black Redstarts begin to display “migratory restlessness” far later than do Common Redstarts.

Whatever environmental/genetic factor that influenced onset of this behavior has affected the wintering site location for each species.

Thought Question: Do the data concerning the hybrids suggest the potential causes of this behavior? Why or why not?

To successfully study the data on the next slide, we need to first look at the predicted and actual correlation of IQ for different groups of humans.

Why do people differ in their test scores? (Part 1)

P – O = parent and offspring

MZ – identical twins

DZ – fraternal twins

Points to Ponder:

a)What do the data comparing MZ groups adopted apart and DZ groups raised together suggest about genes and the environment?

b)What do the P-O data comparing the together group and the adopted apart group suggest about genes and the environment?

3.16 Why do people differ in their test scores? (Part 2)

These data for Spatial ability are similar in TREND to that of Verbal ability.

However, in examining the same two groups as suggested on the last slide…. What sorts of hypotheses can you make concerning genes and the environment relative to verbal and spatial ability?

What test(s) would you recommend to further understand these ideas?

The Fruit Fly

(Drosophila melanogaster)

This species is known as the common fruit fly (or sometimes the vinegar fly).

Thanks to Charles W. Woodworth and Thomas Hunt Morgan, this species is a model organism that is widely used for biological research in studies of genetics, physiology, and behavior.

Charles W. Woodworth (left) is credited with first breeding Drosophila in quantity while he was at Harvard. Thomas Hunt Morgan (right), in his biography says that Woodworth suggested that Drosophila might be used for genetics work.

The six behaviors displayed (A F) represent the sequence of mating behaviors shown in Drosophila melanogaster. These behaviors are able to be quantified in terms of occurrence, but also in terms of time intervals.

All of the developmental stages of Drosophila are potential stages for the observation of behavior.

Fruit Fly Developmental Stages & Life Cycle

Figure 3.24 Genetic differences cause behavioral differences in fruit fly larvae (Part 1)

“Rover” and “sitter” behaviors are displayed by larvae of fruit flies.

Measurement is taken as the larva moves across an agar plate.

In the work displayed, female sitters were mated with male rovers.

Figure 3.24 Genetic differences cause behavioral differences in fruit fly larvae (Part 2)

In this example, we can see when female sitters mate with male rovers, the larvae primarily show the rover phenotype in the F1 generation, suggesting that if a single allele drives this rover behavior, the inheritance is via autosomal dominance.

Question to Ponder:

What alternative explanations are there?

A Female Fruit FlyCarrying Fertilized Eggs

Fertilized Eggs are Laid in Culture Media Containing Chemical Being Studied

Larvae develop having been exposed through egg and larval stage

OR… WITH FURTHER MATURATION

OR… WITH FURTHER MATURATION

Pupae develop having been exposed through egg, larval and pupal stage

Adults develop having been exposed through entire life

Rover/Sitter Tests

Pupation Distance Measures

Adult BehaviorTests

3.17 A single gene affects maternal behavior in laboratory mice

Gathering and crouching behavior is a stereotypical behavior seen in wild-type mice.

The genes believed responsible for driving these behaviors are the fosB genes.

Females who are “knockout” mice for fosB genes do not exhibit typical parental care behaviors.

3.18 Social amnesia is related to the loss of a single gene

In this example, a gene referred to as Oxt is associated with recognition behavior. In the study, the male that is a “knockout” mouse for Oxt will not show a decline in “inspections” of a female in his cage. The inspection rate of an Oxt intact mouse shows a rapid decline across trials, suggesting recognition of the female.

3.20 A coastal Californian garter snake about to consume a banana slug

Could there be a genetic component to food choice….. In Garter Snakes?!?

3.21 Response of newborn, naive garter snakes to slug cubes

In the experiment shown, the researchers obtained newborn snakes (that had never fed) from two different regions and compared their responses to banana slugs.

Prey available for both populations naturally include tadpoles, whereas slugs are found only in the coastal regions.

3.22 A tongue-flicking newborn garter snake senses odors from a cotton swab

The cotton dipped swab has the odor of different potential food items on it. Steve Arnold did this classic work examining the level of interest the snakes had in different food items.

3.27 Surrogate mothers used in social deprivation experiments

Classic work in the 1960s examined social deprivation in primates. In these studies, newborn rhesus monkeys were separated from their biological mother and only allowed to interact with an artificial “surrogate” mother mannequin.

We shall see in a future video the dramatic effects of this isolation had on the monkey’s behaviors.

3.28 Socially isolated rhesus infants

The crouched, scared body posture and poor interactive abilities displayed by these two rhesus monkeys helps to define the major effects of early social deprivation.

The monkey’s would respond in terror to very small noises or stimuli and would tend to not interact with “normally” behaving rhesus monkeys. Instead, these monkeys would tend to sit in one position and would show classic “rocking” behavior.

3.29 Developmental homeostasis in humans (Part 1)

In the graph below, we are seeing the rates of mental retardation in a study of male offspring born of mothers in two populations in WWII Europe. The red line indicates populations who had food restriction, whereas the black line is the population that had no food restriction. Results are statistically non-significant and show that the mother’s internal physiology can compensate for some stressors.

3.29 Developmental homeostasis in humans (Part 2)

Part A (the previous graph showed mental retardation rates, but the graph below (B) looks at the IQ scores of these offspring

(Note: manual and nonmanual refer to the occupation of the father of the offspring in both graphs.)

3.30 Facial symmetry and attractiveness

Humans have a tendency to view symmetry in a characteristic to be more attractive than less symmetry.

Here, we have computer enhanced images of symmetry. The perfect symmetry column was significantly preferred over the normal or high symmetry columns.

David Clark – Alma College

Dr. Clark has studied the wolf spider and how it will create visual communication displays.

3.31 Testing mate choice in a female wolf spider

One of his designs has been to use video footage of a competitor spider showing different behaviors and observe the displays the test subject makes in response.

3.32 Developmental switch mechanisms can produce polyphenisms within the same species

Polyphenism – more than one distinctive, alternative phenotypes in an organism based upon specific environmental pressures.

D = ant/bee caste developmentE = cichlid (territorial/non-territorial)F = aphid soldier caste

3.34 Activity of the gene that codes for gonadotropin-releasing hormone in Haplochromis burtoni

In the cichlid example, we see that there are statistically signficiant differences in GnRH secretion displayed in the two groups within 7 days following change in status.

The change in status gradually reshapes the genes producing this hormone in the brain that affect the gonads and testosterone production.

3.38 Sex differences in spatial learning ability are linked to home range size

Spatial learning differences are apparent in the Meadow Vole based upon sex. However, no such difference is seen in the Prairie Vole.

The difference relates to the mating strategy of each sex. Polygynous male Meadow Voles tended to display much larger territories in the wild than either female Meadow Voles or either sex of Prairie Voles.

Points to Ponder…. How may these results relate to YOUR mouse learning study? Might this article be valuable to cite?

3.39 A virtual maze used for computer-based studies of navigational skills

Virtual Mazes for human studies can find interesting results as well.

3.40 Sex differences in the hippocampus

Spatial Learning is primarily an aspect that is related to the size of the hippocampus of the brain. In the female Brown-Headed Cowbird, the greater spatial ability is associated with her sneak egg laying behavior in the nests of other bird species.

3.41 Operant conditioning exhibited by a rat in a Skinner box

Operant conditioning – a behavioral situation where an animal will associate a volutary action it does with some form of consequence…. the response can be postive, negative or neutral.

Thought Question…. What would be some potential variations seen in Operant Conditioning Responses depending upon the stimuli effect?

3.44 Vampire bats cannot form learned taste aversions

In this experiment, it appears the vampire bat CANNOT learn taste aversions. Note how the other species CAN quickly show this form of operant conditioning.

Question…..Why might this NOT be possible in the vampire bat?