LectureC1 (2025-09-11): Foundations of Learning and Memory

In this lecture, we provide foundations for discussing an important form of plasticity in animal behavior – learning. The response an animal has to its environment can be innate, or it can be modified by experience with its environment, resulting either in short-term changes (short-term learning) or long-term changes (long-term learning) with the possibility of very long-lasting changes (long-lasting learning). We discuss the different benefits and costs of these different forms of learning, which will also involve a brief description of the neural mechanisms underlying learning in animals. We then move to methods of measuring learning in behavioral experiments as well as categorizations for different forms of learning. This will allow us to introduce both non-associative learning (habituation and sensitization) and various forms of associative learning.

Topic highlights:

• the costs, benefits, and mechanisms underlying innate behavior, short-term learning, and long-term learning
  
  • protein recruitment vs protein synthesis in neurons
• "learning curve" and "forgetting curve"
• distinctions between learning, forgetting, and extinction
  • long-lasting memory and memory consolidation
• the basic models of learning:
  • imprinting (and critical periods)
  • non-associative learning: habituation (and repetition) and sensitization (and intensity)
    • the combination of the two as information filters
  • associative learning (conditioning)
    • operant conditioning
      • prepared, unprepared, contraprepared animals 
      • reinforcement and punishment
        • both positive and negative
    • classical conditioning
      • unconditioned/conditioned stimulus/response

Important terms: learning/plasticity/neuroplasticity, proboscis extension reflex (PER), forgetting, extinction, learning/forgetting/extinction curve, innate behaviors, short-term memory (STM)/working memory, memory consolidation, long-term memory (LTM), long-lasting memory, stimulus, response, imprinting, habituation, sensory adaptation, sensitization, conditioning/associative learning, classical conditioning, unconditioned/neutral/conditioned stimulus/response, operant conditioning, reinforcement (positive and negative), punishment (positive and negative), prepared/unprepared/contraprepared

Lecture B3 (2025-09-09): Quantitative Approaches in Behavioral Genetics

In this lecture, we pivot from describing behavioral methods for disentangling nature (genetics) from environment (nurture) and turn toward more quantitative approaches to assessing heritability and the contribution of genes to phenotype. First, we return to the topic of "heritability" as a measure of the contribution of genetic variance to observed phenotypic variance and define two different forms of heritability – broad-sense heritability (which includes non-additive genetic effects) and narrow-sense heritability (which only includes additive genetic effects). We show how to use parent–offspring phenotypic analyses to measure narrow-sense heritability ("h squared"). As heritability will vary in a population if the corresponding trait is under selection, we then discuss how to use genetic analyses to infer whether a population is at equilibrium or currently in the process of evolving through selection or by other means. This gives us an opportunity to discuss the "Hardy–Weinberg equilibrium" and discuss some practical ways to use it. We then conclude with an introduction to QTL mapping and GWAS for understanding which combinations of genes contribute to a particular behavior (and how).

Topic highlights:

• heritability: broad-sense and narrow-sense
• effect of selection on heritability
• Hardy–Weinberg equilibrium/principle
• quantitative trait loci (QTLs) and QTL mapping
• genome-wide association studies (GWAS, GWA studies)

Important terms: heritability, narrow-sense heritability, broad-sense heritability, Hardy–Weinberg equilibrium, quantitative traits, quantitative trait loci (QTL), QTL mapping, genetic markers, single-nucleotide polymorphisms (SNPs), linkage map, genome-wide association study (GWAS, GWA study)

Lecture B2 (2025-09-04): Methods for Disentangling Nature and Nurture

In this lecture, we continue our discussion of the combined role of genetics and the environment in the expression of a phenotype. We start by focusing on concepts from molecular genetics related to testing for the role of a single "candidate gene" using techniques like RNA knockdown. We then consider the role of epigenetics in the expression of a phenotype and discuss DNA methylation, cell differentiation, behavioral epigenetics, and genomic imprinting. Ultimately, this leads us back to seeking methodological ways to identify when a behavior has a strong genetic or environmental basis (before we look into which genes are playing the largest role). So, we introduce cross fostering, twin studies, and common gardening, which are three different ways to test whether a behavior is being determined more by the environment or by the genes.

Topic highlights:

• exploration of molecular genetics applied to the analysis of behavior
  • "candidate genes" approach and RNA knockouts and CRISPR gene editing
  • introduction of "epigenetics" ("GxExE to P")
    • brief introduction to histone modifications
    • introduction to DNA methylation 
    • discussion of role in cell differentation
    • introduction to "behavioral epigenetics" and social-insect examples analogous to cell differentiation
    • introduction to "genomic imprinting"
• exploration of common experimental methods to disentangle contribution of gene and the environment in behavior
  • definition and examples of "cross fostering"
  • definition and examples of "twin studies"
  • introduction to "common gardening"

Important terms: molecular genetics, candidate gene, RNA knockout, epigenetics, epigenotype, DNA methylation, behavioral epigenetics, genomic imprinting, sympatric, cross fostering, twin studies, common gardening/transplant experiments

Lecture B1 (2025-09-02): Foundations of Behavioral Genetics

In this lecture, we cover foundational topics in modern synthesis of behavioral genetics. The lecture starts with the nature-versus-nurture debate and its historical roots in tensions between American psychologists and European ethologists (fueled in part by geopolitical contexts at the time). Ultimately, we cover the more modern, integrative, "nature-via-nurture" perspective where phenotype reflects effects of both genes (potentially many genes) and their interaction with the environment ("GxE"), and biologists are interested in understanding the relative contributes of both (e.g., with "heritability" quantifying the relative contribution of genotypic variation to phenotypic variation in a population). We then discuss different historical fields that have contributed to the modern synthesis and examples of what they have contributed. That gives us an opportunity to discuss phenomena identified in evolutionary biology that help to explain the counterintuitive observation that, for reasons unrelated to genetic drift, many traits that have an apparent fitness cost are still maintained (or at least not purged) in a population. We close looking forward to a unit on behavioral genetics that will introduce methods that behavioral ecologists use to try to separate genetic and environmental effects as well as quantitative tools for better understanding which genes contribute in complex ways to any particular phenotype/trait.

Topic highlights:

• historical nature-versus-nurture debate and contributions to its origins in ethology-vs-behaviorism
• definitions of gene, allele, genotype, character, trait, phenotype, and expression (as in "gene expression" and "phenotypic expression")
• nature-via-nurture perspective and "GxE to P" ("G by E to P" or simply "G by E")
• definition of "epistasis" and its interpretation as GxGxE
• definition of "epigenetics" and its interpretation as GxExE
• rough definition of "heritability"
• foundations of the modern synthesis of the genotype-to-phenotype map, with focus on:
  • domestication/artificial selection
  • phylogeny (including definition of a "cladogram")
  • quantitative and biometrical genetics
    • definition of "quantitative trait"
  • evolutionary and population genetics
    • definition of "ecotype" as a genetically (and generally geographically) distinct subpopulation that has been locally adapted to its home environment
      • ecotypes are a product of natural selection (whereas the "founder effect" and "genetic bottlenecks" are related to genetic drift)
    • discussion of notable evolutionary processes that maintain traits for counterintuitive reasons, including:
      • correlated characteristics
      • phylogenetic inertia
      • the handicap principle
      • disruptive (or diversifying) selection

Important terms: G by E (GxE), G by E to P (GxE->P), GxGxE, GxExE, epistasis, epigenetics, ecotype, gene, allele, genotype, character, trait, phenotype, gene/phenotypic expression, genotypic variance, phenotypic variance, heritability, quantitative trait, artificial selection/breeding, phylogeny, cladogram, correlated characteristics, phylogenetic inertia, handicap principle, disruptive/diversifying selection

Lecture A2 (2025-08-28): Physiology and Evolution in Animal Behavior

In this lecture, we consider the different historical approaches that have led up to modern behavioral ecology, including ethology and behaviorism. This gives us an opportunity to discuss von Uexküll's "umwelt" and give various examples of animals whose sensory and perceptual experience is notably different than the experience of a human. This sets us up to discuss how important it is to consider the physiological mechanisms and constraints that can limit what kinds of behaviors are able to evolve, and we use ring dove mating as an example of this. We close by looking ahead to the next unit on behavioral genetics and discuss how the four different mechanisms of evolution (natural selection, genetic drift, mutation, and migration) also can shape the patterns of behaviors that can evolve. Overall, this lecture helps to draw boundaries around what is the field of behavioral ecology while also establishing that those boundaries are necessarily porous and permeable and must both be influenced by and influence surrounding fields from physiology and evolution.

DUE TO TECHNICAL DIFFICULTIES, THE START OF THIS LECTURE HAD TO BE DONE ON THE WHITEBOARD. EVENTUALLY, WE FLIP BACK TO THE SLIDES (which are easier to review in the recording).

Topic highlights:

• historical approaches to animal behavior, including:
  • behaviorism
  • ethology (in a classical sense)
• umwelt
• the relationship between animal behavior and each of physiology, neuroscience, sensory biology, and endocrinology
• the relationship between animal behavior and each of genetic drift, natural selection, mutation, and migration
• refresher on the meaning of genetic drift

Important terms: behaviorism, ethology, umwelt, genetic drift, mutation, migration, natural selection 

Lecture A1 (2025-08-26): Animal Behavior and the Scientific Process

In this lecture, we review the scientific foundations of animal behavior. We define a causal question, a hypothesis, a theory, an experiment, and a prediction and how they all relate to each other. We emphasize that a hypothesis is not an IF–THEN statement, but a prediction is. We also cover Tinbergen's four questions (the four different levels of analysis in biology and behavioral ecology). This is all done in the context of talking about the cephalopod eye (with an octopus and a cuttlefish example) and its comparison to the vertebrate/human eye. We end with a short discussion of how to define "behavior" most generally and with the most utility.

Topic highlights:

• cephalopod eye structure
• scientific-process terminology:
  • causal question
  • hypothesis
  • prediction
  • experiment
  • theory
• "Tinbergen's four" (questions/causes), the four levels of analysis:
  • function/adaptation/utility
  • phylogeny/evolution
  • ontogeny/development
  • mechanism (also sometimes called "causation", but I have omitted that from this course as it might be confusing)
• phylogenetic trees
  • chronograms
• evolutionary and developmental constraints between function and mechanism
• the difficulty  in defining "behavior"

Important terms: causal question, hypothesis, prediction, experiment, theory, Tinbergen's four questions (or causes), function/adaptation/utility, phylogeny/evolution, ontogeny/development, mechanism, chronogram

Lecture 0 (2025-08-21): Course Introduction

This lecture introduces BIO 331 (Animal Behavior) and its policies. Most of the lecture covers administrative and structural aspects of the course, but in the middle there is an examination of the "stotting" behavior that occurs in many ungulates where students propose different hypotheses for the phenomenon. The stotting example is meant to motivate the kinds of things that will go on in the course.