E.g. why do birds sing? -- One of the defining features of songbirds is the ability
to learn and produce song. The 4 questions covered in lecture 2 describe
influences on how this develops.
GENES & BEHAVIOUR
“Jim twins”
Adopted 4wks old
Both named James by adoptive parents
(unknown to each other)
Reunited at age 39 in 1979
Part of large study on identical twins raised apart, trying to identify
genetic vs environmental determinants of behaviour. Definitely a genetic
influence on behaviour here. Study found that identical twins raised apart
are as similar in factors such as personality and intelligence as identical
twins raised in the same environment.
Both:
six feet tall and 180 pounds
suffered tension headaches since age 18
gained ten pounds at the same time
did carpentry, mechanical drawing,
and block lettering
had law-enforcement training and had been a part-time deputy sheriff in
Ohio
married to women named Betty and divorced from women named Linda
first son James Alan or James Allan
named their pet dog "Toy”
vacation in same 3-block beach area in Florida
SINGLE GENE – ROVERS VS.
SITTERS
Behavioural traits are often determined by many
genes but some are dictated by single genes.
Natural polymorphism in wild
o 70% rovers (move around more to search for
food)
o 30% sitters
, Cross sitter x rover
o F1 generation nearly all rovers
o F2 generation gives a 3:1 ratio of rovers:sitters, revealing that this
is a single gene effect with the Rover allele dominant
for gene
o Encodes brain-expressed protein
o Differences in foraging behaviour
o Differences in memory
rovers have better short-term memory
sitters have better long-term memory
o Both rover and sitter traits may be adaptive in different contexts.
FEW
GENES –
BURROW
BUILDING
MICE
However, most
behaviours are
more complex
than this
Different species
of mice have
different burrow
shapes that are
associated with