Diversity of Life

**BIODIVERSITY TITLE

About 1 million species have been named/described to date. There are estimated to be up to 50 million species total (or more?).

Most of these are animals, and each species is unique in its behavior.

 **KNOWN SPECIES

**ESTIMATED SPECIES

What is behavior?

**DEFINITION TEXT

A definition of behavior: All observable or measurable muscular and secretory responses an animal makes to changes in its internal or external environment.

Problem- doesn't fully account for analysis of cognitive/neural processing.

In practice, the study of animal behavior often involves measuring movement and its products/results.

-Example: Learning in laboratory rats and pigeons- learning is measured by changes in the probability of performing tasks (e.g., pressing a bar) with experience.

**SKINNER BOX

-Example: the study of birdsong relies heavily on measuring the consequences of movement (sound).

**SONGBIRD/SONOGRAM

-Example: The study of behavior can also rely heavily on measuring an animal's physiology.

 **MOTH EAR NEURON ACTION

How does animal behavior fit into psychology?

**FIT TEXT

**WILSON DIAGRAM

To understand a major practical difference between animal behavior and the rest of psychology, think of some common ways of collecting psychological data.

In practice, animal behavior differs from most of psychology because humans don't share a common language with other species.

However, the methods of observation used in animal behavior can be and often are used by psychologists. What are some situations where use of animal behavior methods is necessary in psychological research?

Why should scientists, including psychologists, study animal behavior?

**WHY TEXT

**LIST OF REASONS

1. We depend on other species for our own survival and well-being. Animals provide food, clothing, pollination, waste removal, companionship, etc. Humans have been interacting with other species, both domesticated and non-domesticated , throughout our existence. Our interactions with other species, and our understanding of them, has a behavioral basis.

Biophilia concept (E.O. Wilson): we rely so heavily on animals (and other life forms) that they are essential to our psychological and cultural health.

2. We are animals. Knowledge of other species informs us about ourselves. As evolutionary biologists we recognize that distantly related life forms, as well as closely related ones, have much to teach us about the human condition.

What is the only non-human species known to have an abstract, symbolic language?

Animals provide useful model systems for studying the mechanisms and function of human behavior. There is not necessarily a requirement for close evolutionary relatedness for predicting behavioral similarity.

For example, a model for studying Alzheimer's disease has been developed in Drosophila (fruit flies).

Recent advances in molecular biology (genetics) show that we are more genetically similar to other species than was previously recognized.

Rough estimates of gene sharing: 98% with other great apes; 70% with insects; 30% with plants.

3. Biological conservation: an understanding of behavior is critical to preserving functioning ecosystems (including their human occupants).

The History of Animal Behavior as a Science:

**ETHOL/COMP PSYCH TABLE SLIDE

Two major schools of thought have contributed to the development of modern animal behavior.

	Comparative Psychology (USA)	Ethology (Continental Europe)
Main approach	Experimentation	Observation
Setting of research	Laboratory	Field, natural conditions
Focus of theory	Learning	Instinct
Main level of questioning	Development	Evolution
Motivation	Animals as models of humans	Animals for own sake
Subjects	Mammals (Norway rat)	Birds, Fish, Insects

Ironically, there was a heavy emphasis on a few (or one!) model species in behavioral analysis in "comparative" psychology. In part as a response, ethologists stressed the need to embrace life's diversity, in order to fully understand behavior.

**PUBLICATIONS BY DECADE

In 1973, the Nobel Prize in Medicine was awarded jointly to three European researchers for developing Ethology as a science: Konrad Lorenz, Niko Tinbergen , and Karl von Frisch.

**PORTRAITS

A modern approach to framing hypotheses in animal behavior:

Types of behavioral hypotheses can be classified based on Niko Tinbergen's four levels of questions about causation.

**4 LEVELS TEXT

1. Control: Also called proximate mechanisms of behavior. For example, we might ask, "What are the physical and chemical mechanisms that lead to behavioral patterns?"

Can be studied in an individual

Can involve both internal and external factors, and their interaction

EXAMPLES OF CONTROL QUESTIONS AND HYPOTHESES

2. Ontogeny (Development): Patterns of change in behavior over time

Can be studied in an individual

EXAMPLES OF DEVELOPMENTAL QUESTIONS AND HYPOTHESES

3. Function: Also called adaptive value of behavior. Answers the question, "How are certain behavioral patterns maintained in populations or species?"

Studied in populations

Involves measuring both genetic and cultural transmission of behavioral traits

The goal is to determine the effects of behavioral characteristics on evolutionary fitness- often assumes evolution by natural selection

EXAMPLES OF FUNCTIONAL QUESTIONS AND HYPOTHESES

4. Phylogeny: Tracing the evolutionary history of behavior

Studied in populations

Involves comparison of behavior among different species. Must include some information on evolutionary history- how different species are related to each other.

EXAMPLES OF HISTORICAL QUESTIONS AND HYPOTHESES

Note that proximate and ultimate hypotheses are not alternative explanations: they are different levels of explanation.

There are several levels of complexity of behavioral patterns that we can measure:

**COMPLEXITY TEXT

1. Action pattern- Basic unit of behavior; a simple motor act or movement. Performance is often stereotyped (little variation).

2. Sequences of action patterns

3. Spatial distribution of action patterns (e.g., home range)

4. Interactions with other animals- can be either ecological (with other species) or social (with the same species).

Types of variation that are important to animal behavior:

**VARIATION TEXT

-animal species differ from each other (dogs and cats);

-individuals differ from each other (your companion animal versus someone else's);

-individuals change over time (your companion animal as a baby versus as an adult).

In animal behavior research, it is very important (and sometimes difficult) to define how variables are measured (methods of data collection) and the context in which they are measured.

Behavioral variables must be defined operationally to insure repeatability of scientific results: operations is the attempt to define variables and how they are collected in a precise way, so that other scientists understand them clearly. Ideally, if another scientist repeats the study, the same relationships between variables will be found. In a scientific paper, the Materials and Methods section aims to make the study operational and repeatable.

A final note: be aware of the difference between Observations and Experiments.

**OBS/EXPER TEXT

-In an experimental study, typically the values of one or a few variables (conditions) are set by the scientist, and the effects on the other variable are measured. Subjects are assigned randomly to different treatments (values of the manipulated variable). Experiments can give strong evidence for causation.

-It does not involve a difference between laboratory and field studies.

-Observational studies (often used in animal behavior) involve measuring the values of variables and testing whether they are correlated. Observational studies can be used to test hypotheses- what is their weakness, when compared to experiments?