BIO3052 Lecture Notes - Lecture 19: Gene Mapping, Wild Type, Heritability
30 May 2018
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GENETICS OF BEHAVIOUR I
NATURE VS NURTURE AND EVIDENVE FOR THE GENETIC BASIS OF BEHAVIOUR
• What determines behaviour?
o Behaviour and genetics work in combination
o One cannot exist without the other
o I.e. if 100% nurture, there would be no genetic component, if 100% genetic, all
behaviours would need to be completely inherited with no scope for learned and
modified behaviours
• Phenotype: any measurable aspect of an individual eg. behaviour
= genotype x environment
• Genotype: genetic constitution of an individual and refers to either alleles of one gene possessed
by the individual or its complete set of genes
• Eiroet: athig that’s ot the gees eteral to geeti aterial
• Innate/instinctive behaviours:
o For basic life functions
o Eg. sea turtle hatching and go to sea (almost always nowhere to go)
-> social interactions with nest mates
-> urban lights disrupt spatial orientation
-> incubation temperature may influence
o Something innate has a strong environmental aspect eg. breast feeding
• Genetic basis of behaviour – what evidence do we have?
o Finding differences in different individuals
o Finding differences in twins that grew up in different environments
Behaviours are species specific
o Eg. burrowing behaviour in deer mice (peromyscus)
Burrowing is part of behaviour -> extended
phenotype
Burrows for predator avoidance,
thermoregulation, food storage, social
interaction and mating
Differences reflect: habitat/environment and
selection
Burrow attributes differ among species
o
Behaviour exhibits phylogenetic
relationships
o Eg. burrow evolution
Small and simple to long multi-tunnel burrows
Addition of an escape tunnel
Gradual changes over time
find more resources at oneclass.com
find more resources at oneclass.com
Behaviours may be inherited
o Eg. exploratory behaviour in great tit birds (parus major)
Experimental design: introduce birds to arena
and score number of flights/hops over 2 minutes.
Exploratory behaviour is measured twice for each
bird and compare to parents-offspring and
siblings
-> measuring how long it takes for individuals to
enter arena (shy = longer, bold = faster)
Results: behaviour was highly repeatable and
heritable (score of mother is related to score of
offspring, also siblings)
Behavioural change from genetic
alteration (occurs in response to
DNA alteration)
o Eg. maternal care in mice
-> fosB gene affects maternal care
Wildtype = has fosB gathered displaced pups,
kept them warm and nursed them
Mutant = no fosB displayed normal behaviour
however were indifferent to pups, failed to
round them up and had lower pup survival
-> maternal care instincts have been knocked out
o Eg. courting behaviour in mice
-> Oxt gene for oxytocin production
Mutats ith ot kok out has aesia, a’t
recognise females that have recently associated
ith ildtpe ales reeer ad do’t
inspect familiar females as much)
Behaviours can respond to selection
o Eg. Aggressive behaviour in Drosophila
Experimental design: select the aggressive males
to mate (selection process) and have 2 replicate
lines and 2 control lines (random mating)
Results: after 10 generations, massive increase in
aggressive behaviour which is consistent with the
expected results if the behaviour was inherited
-> behaviour still increased after 21 generations
o Eg. Pollen hoarding in honeybees
Experimental design: 2 selective lines, 1 hive with
high pollen and other with low pollen
-> looking at hives and sampling to see how
much pollen is present
Results: after 3 generations there was 6 times
more pollen in the high pollen strain (selected for
high pollen). Bees in high pollen hive had
preference for pollen over nectar and low pollen
bees had preference for nectar
-> different foraging strategies and preference
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Nature vs nurture and evidenve for the genetic basis of behaviour: what determines behaviour, behaviour and genetics work in combination, one cannot exist without the other. I. e. if 100% nurture, there would be no genetic component, if 100% genetic, all behaviours would need to be completely inherited with no scope for learned and modified behaviours: phenotype: any measurable aspect of an individual eg. behaviour. = genotype x environment: genotype: genetic constitution of an individual and refers to either alleles of one gene possessed by the individual or its complete set of genes, e(cid:374)(cid:448)iro(cid:374)(cid:373)e(cid:374)t: a(cid:374)(cid:455)thi(cid:374)g that"s (cid:374)ot the ge(cid:374)es (cid:894)e(cid:454)ter(cid:374)al to ge(cid:374)eti(cid:272) (cid:373)aterial(cid:895) Innate/instinctive behaviours: for basic life functions, eg. sea turtle hatching and go to sea (almost always nowhere to go) Behaviours are species specific: eg. burrowing behaviour in deer mice (peromyscus) Burrowing is part of behaviour -> extended phenotype. Burrows for predator avoidance, thermoregulation, food storage, social interaction and mating. Burrow attributes differ among species: eg. burrow evolution.
