Animal Behavior Unit 1

Tinberg’s 4 questions

1) Developmental

2) Genetic architecture

3) Evolutionary history

4) Adaptive function

Proximate cause

Immediate, mechanistic behavioral triggers

Ultimate causes

The ecological function of a behavior

Epigenetics

Non-genetic heritable genomic alterations

Microevolution

Allele frequencies

Macroevolution

Changes in species numbers

3 requirements of evolution

1) Trait variations on the population level

2) Differential fitness

3) Trait heritability

Parent-offspring regression

A + or - relationship existing between trait values of parents and offspring

Experimental evolution

Groups of individuals are subjected to different survival regimens

Stabilizing natural selection

Reduces variety, more intermediates

Directional natural selection

Increases frequency of extreme end of trait

Separative natural selection

Separation into two extremes

Phenotypic plasticity

Ability for a genotype to produce multiple phenotypes depending on extrinsic characteristics

Phenotypic flexibility

Ability to change phenotype in response to environment or demand, reversible

Developmental flexibility

Environment during developmental process produces permanent effects

Phylogenetic tree branch length

Indicates evolutionary time

Nodes

Represents divergence of lineages

Principle of parsimony

Rule stating the simplest tree with the least number of changes is most likely

Common garden

Controlled environment in which captive animals can be tested

Major genes

Large effect on phenotype

Minor genes

Usually interact to produce phenotype

Pleiotrophy

Multiple genes convening to produce phenotype

Quantitative traits

Exist on a continuous spectrum, multiple genes

Qualitative trait loci

DNA stretches that contain or are linked to an organismal trait

SNPs

Variations in nucleotides between splice sites

KO studies

A gene is disabled and behavior analyzed

Personality

Consistent behavioral changes over time or across different contexts

Steroids

Cholesterol derived, sex hormones from gonads and cortisol from adrenals

Monamines

Single amino acid pheromones. Hydrophilic

Peptides

Amino acid chain pheromones. Hydrophilic

Monamine and peptide transportation

Hydrophilic, allowing mixing with blood

Steroid transportation

Hydrophobic, requiring transport proteins

Steroid bonding

Bond to internal receptor, influence gene expression

G protein steps

Hormone triggers GTP→GDP, triggers enzyme, enzyme triggers cAMP production,

Upregulation

Increases number of receptor = greater sensitivity

Pathway involved in sex change hormones

Aromatase

Testosterone

Increases competitiveness, decreases parental care

Oxytocin

Receptor richness rewards monogamous behavior

Steroid effects

Immunity and reproductive reduced, feeding and movement altered

Protein-bound pheromones

Longer ½ lives

Corticosteroids

Cortisol form of birds and reptiles

Protandry

Male → female

Protogyny

Female → male

Dominance

Determined by testosterone