Lecture 1: Overview

• What is Behavior?


  The way an individual interacts with their environment or others .

  Internally coordinated responses to internal/external stimuli.
• Ethogram: a formal description or inventory of an animal’s behavior.

  • can include time, frequency, rate, time until occurence, and strength.
• Observational data can raise new and interesting questions and hypotheses.

  • Ex: A negative correlation between time spent feeding and stereotypic behavior.
• Tinbergen’s Four Questions: development, mechanism, evolutionary history, and adaptive value. 
• Proximate: explanations of behavior are immediate, mechanistic, and act within the lifespan of an individual.

  • Answer how questions.
  • Development
  • Mechanism
• Ultimate: explanations of behavior focus on the adaptive value and evolutionary history of behaviors. 

  •  Answer why questions. 
  • Evolutionary History
  • Adaptive Function
• Development: how genetic developmental mechanisms influence the assembly or an animal and its internal components.
• Mechanism: how neuronal hormonal mechanisms that develop in an animal during its lifetime control what an animal can do behaviorally.
• Evolutionary History: the evolutionary history of a behavioral trait as affected by descent with modification from ancestral species. 
• Adaptive Function: the adaptive value of a behavioral trait as affected by the process of evolution by natural selection.
• "Nothing in biology makes sense except in the light of evolution.”
• Explanatory Power of Evolution Example:

  Why does a male sometimes harm the offspring of females in his group? 

  • Hypothesis 1: Aggressive response caused by overpopulation and crowding when languars are being fed.
  • Hypothesis 2: Causes females to resume ovulation, providing a reproductive advantage to killer males.
  • Predictions Made: Males are unlikely to attack their own progeny. Females will resume ovulation after losing an infant.
• How are Hypothesis Generated?

  Observations of animal behavior made in the field or lab.

  Models based on algorithms about ecology or evolution of organisms.
• Measures of Central Tendency is one number that indicates the centrality of the data values. 

  • Mean: add up all the values and divide by the number of data points.
  • Median: the middle value of a set of ordered data. 
  • Mode: most common value in the data. 
• Measures of Dispersion describe the variation in the data.

  • Range: difference between the highest and lowest measurements.
  • Variance: a non-negative number that provides information on the data spread. The larger the variance, the more the dispersion. 
  • Standard Deviation: square root of the variance. 
  • Standard Error: the standard deviation divided by the square root of the sample size. 
• Correlations:

  Correlations represent two variables that vary together predictably.

  • Positive Correlation: X increases as Y increases
  • Negative correlation: X decreases as Y increases
• Correlation does not dictate causation.

  • Pirates decreasing as global temperatures increasing example.
• Research Question: a brief statement of something we would like to understand 

  Research Hypothesis: an explanation based on assumptions that make a testable prediction. 
• Digger Bees Centris pallida)

  Q: Why are the males digging?


  A: To get to the new virgin females that have developed and are leaving the larva.
• Scramble Competition: males fight to get to the new females first.
• Observational Studies: observe certain aspects that are already there and then draw conclusions.

  Experimental Studies: set up an actual new variable to test.
• Statistics uses probability theory to produce conclusions from available data.