Non-genetic transmission Flashcards
Definition of non-genetic transmission?
-factors acting via one individual that influence behaviour/development of another who will pass on those influences to another
Definition of vertical transmission?
- between generations, parent to offspring
- parents behaviour directly influences their offspring’s behaviour
- similar pattern to genetic inheritance
Definition of horizontal transmission?
-within generations, between peers
What are the different forms of non-genetic transmission?
- parental effects
- social learning
- symbolic representation
What are the maternal effects on behaviour?
- variation between
- can act pre or post birth
- some effects take place inside and/or outside the womb
- developmental legacy is transferred from mother to daughter
Example of maternal effect on pre-birth?
- mongolian gerbil
- when females are in the womb with a large number of brothers they’re exposed to more testosterone
- when born they have later sexual maturation and increased aggression
- also produce more male biased offspring themselves
Example of maternal effect outside womb?
- cabbage butterfly
- female selects host plant and lays eggs there
- once hatched they feed on it and acquire a preference for that plant
- will then lay their eggs on same plant
Example of maternal effect taking place both inside and outside of womb?
- rabbits
- offspring choose same foods that their mother ate when in the womb
- same effect after birth with the flavourings that come through in the milk
- pre-birth factor was stronger in the case of fostering rabbits after birth
What are the paternal effects on behaviour?
- variation between individuals is better explained by considering measures of the father than the genotype
- may act pre- or post-birth
Example of paternal effect on pre-birth?
- minotaur beetles
- horned males helped roll dung beetles that females lay eggs in
- those that hatch from the larger balls grew horns
- size of ball determined gender production of horns rather than genetic features
Example of paternal effect on post birth?
- sparrows
- males have black throat patch that differs in size regarding dominance
- those born to large patched but fostered by small patched developed a small patch
What effect does social learning have on behaviour?
- differs from self-learning as it’s heritable
- in some species there’s opportunities for vertical transmission
Galef and Wigmore (1983)
social learning in rats
- those fed a chocolate diet and cinnamon diet
- introduced to group of rats on control diet
- control rats shifted preference to match chocolate or cinnamon
Example of vertical transmission in social learning?
- zebra finches
- sons and fathers calls are almost identical
- when deafened the song the son produced was nothing alike
Example of horizontal transmission in social learning?
- song sparrows
- calls that neighbours have are more similar to each other than those who weren’t local
