BIOL 3360 Animal Behaviour - Lecture Notes PDF

BIOL 3360: Animal Behaviour Instructor: Dr. Kevin F 1  Reminders Quiz this Fri, Oct 25th in EITC E2 155 Ethogram full project due Fri, Oct 25th, 10:30am, submit through UM Learn BIOL 3360: Today The Developmental and Molecular...

BIOL 3360: Animal Behaviour Instructor: Dr. Kevin F 1  Reminders Quiz this Fri, Oct 25th in EITC E2 155 Ethogram full project due Fri, Oct 25th, 10:30am, submit through UM Learn BIOL 3360: Today The Developmental and Molecular Bases of Behaviour spatial learning cont’d, evo-devo, polyphenisms and polymorphisms, case studies  LAST DAY: spatial learning Location Colour Spatial task: remember a location of a circle on a screen Non-spatial task: remember colour of a circle on a screen  LAST DAY: spatial learning Location Colour Non-spatial task: remember colour of a circle on a screen =Clark’s nutcracker’s have not evolved all-purpose learning ability  Evolutionary Development (Evo-Devo) approaches: Case study – montane and prairie voles Vastly different animals Prairie voles: (insects to humans) can share form pair bonds genes with similar functions (e.g. Hox genes for body plans) Evo-devo approach (modification of an ancestral pattern of developmental mechanisms) can extend to research on behaviours E.g. hormone vasopressin and associated gene common across mammals (including us) Montane voles: do not Involved in social bonding; differs form pair bonds across polygynous montane vole  Examining vasopressin in 2 closely related species of voles (comparative method) Prairie voles  in many populations, males & females are monogamous Form long-term relationships Both provide parental care to offspring Montane voles  males & females are polygynous Do not form long-term relationships Females provide parental care to offspring  Evolutionary Development (Evo-Devo) approaches: Case study – montane and prairie voles E.g. hormone vasopressin and Prairie voles: associated gene common form pair bonds across mammals (including us) Questions: Do monogamous prairie voles differ from polygynous montane voles in production of vasopressin? Is vasopressin and associated gene (avpr1a) important for social behaviour/mating system? Montane voles: do not form pair bonds  Evolutionary Development (Evo-Devo) approaches: Case study – montane and prairie voles E.g. hormone vasopressin and Prairie voles: associated gene common form pair bonds across mammals (including us) Experiments: 1) compare distribution of vasopressin receptors in brain 2) add avpr1a gene and measure behaviour 3) increase vasopressin levels in brain of pair-bond species and measure social behaviour/V1a Montane voles: do not form pair bonds  Applying Evo-Devo to behaviour Vasopressin  sent to ventral pallidum  stimulates vasopressin 1a (V1a) receptors  provides rewarding sensations S. Phelps Prairie Vasopressin receptors in black Vole Hormone is linked to a gene  Vasopressin 1a protein is encoded avpr1a gene  Case study – montane and prairie voles 1) compare distribution of vasopressin receptors in brain Vasopressin receptors in black Montane voles: do not form pair bonds V1a-receptors Fewer receptors in VP Montane vole brain More receptors in VP Prairie vole brain Prairie voles: Higher reward feedback to prairie voles form pair bonds Variation matches social behaviour!  Case study – montane and prairie voles 3) increase vasopressin levels in brain of pair-bond species and measure social behaviour/V1a Experimentally increased vasopressin directly to brain Increasing levels of vasopressin only increases affiliative behaviour in monogamous species (PVs) =evidence avpr1a/ vasopressin critical in vole social behaviour Affiliative behaviours (positive social interactions) increased in prairie voles only, no montane voles Why did increasing vasopressin not increase Prairie voles: form pair bonds affiliative behaviour of montane voles?  Case study – montane and prairie voles 2) add avpr1a gene and measure behaviour Add additional copies of avpr1a gene in VP brain region = more receptors = increased affiliative behaviour for prairie voles with familiar females ventral caudate Control palladium -different gene Prairie voles: putamen form pair bonds  Evolutionary Development (Evo-Devo) approaches: Case study – montane and prairie voles Prairie voles: Putting all vole work form pair bonds together! evidence avpr1a/ vasopressin critical in vole social behaviour =direct causal link from genetic variation (allele length in regulatory gene avpr1a) to receptors to behavioural variation(reproductive/aff iliative behaviour) Montane voles: do not form pair bonds  Early life developmental conditions: proximate hypotheses for how early life conditions influence later life fitness Some species develop normally without much interaction from their species… contrast to our song Brush Turkey: Incubation temperature learning predicts sex. 34℃ leads to equal sex ratio discussions! Young develop normally without adult interaction  Early life developmental conditions: developmental homeostasis (despite deficient conditions) Development under poor Embargo=food shortage conditions does not always impact future behaviours Developmental homeostasis: Species-typical development despite inadequate developmental environment E.g. humans reared under Nazi occupation of Netherlands during WW2 with food deprivation had similar test scores to those not food deprived Early life developmental conditions: developmental homeostasis Development under poor conditions does not always impact future behaviours But it’s complicated! Recall developmental constraint hypothesis where early-life environment can impact fitness later in life (e.g. development of song learning under nutritional constraints)  Developmental switch mechanisms: switching between different behavioural phenotypes Polyphenism = special type of phenotypic plasticity (developmental plasticity) – 2 or more distinct phenotypes are produced by the same genotype as a result of differing environmental conditions (think epigenetics) Challenge: identifying the proximate causes (environmental cues) that drive the expression of each phenotype  Developmental switch mechanisms caste/job territorial or not Anti-predator armour or not (aphids)  Developmental switch mechanisms: Case study: Tiger Salamander (Ambystoma tigrinum) Phenotype: Cannibal Non-cannibal Cannot be predicted ahead = evolution of switch Larger, Not larger, Environmental most others share pond with relatives Triggers: unrelated  Developmental switch mechanisms: Case study: dung beetles High nutrition = horns Low nutrition = no horn Regulated by genes: reduced expression of InR gene (insulin receptor gene expression) in smaller males, Hh gene part of signaling pathway of switch point for horn growth Switch-point Developmental time in which the phenotypic expression occurs (e.g. grow horns or not)  Developmental switch mechanisms: Polyphenism can occur later in life cycle changes can occur after development Subordinate males of the fish Astatotilapia burtoni react very quickly (within minutes!) to the absence of a dominant rival Behaviour and morphology change connected to surge in activity egr-1 gene Subordinate male Dominant male  Reproductive morphs in ruffs – related to supergenes (whole bunch of linked genes stuck on same chromosome) Ruff (Calidris pugnax)  Reproductive morphs in ruffs – related to supergenes (whole bunch of linked genes stuck on same chromosome) Behavioural polymorphism: not changing during development or later Territorial Non-territorial Non-territorial Supergene: DNA region containing many linked genes that influence a behavioural phenotype  Reproductive morphs in purple martins Polyphenism, not polymorphism, because changes between 1st-2nd yr. Adult female After-second year Second year male, male, female-like appearance, arrive earlier arrive later Reproductive morphs in white-throated sparrows – related to supergenes Responses to song intrusion ERS1 expression assoc. aggression Polymorphism - does not change over lifetime of animal ERS1 expression higher white stripe Reduce ERS1 expression = less aggression White stripe males pair with tan stripe females & vice versa White stripe phenotype = more aggressive; tan stripe = more parental care  BIOL 3360: Assigned Readings Chapter 3, The Developmental and Molecular Bases of Behaviour , pages 68-87. Animal Behaviour. 12th Edition. Rubenstein 28