Evolution Flashcards
Which type of selection focuses on reducing variation to identify the most adaptive trait for the environment the individual finds themselves in and this characteristic is passed on across generations?
Natural selection
-selection of more beneficial traits
Evolution is selecting which type of traits?
selecting the most adaptive traits
-explain their adaptive function (extroversion) and variation (high/low)
Natural selection: selection of more beneficial traits
Traits have fitness, name the 2 indicators of fitness adaption:
(1) fecundity [number of offspring]
(2) survivorship [live long enough to reproduce]
Traits develop as fitness indicators
fecundity means
[number of offspring]
survivorship means
[live long enough to reproduce]
Name the 3 pattern types of Natural selection:
Directional selection
Stabilising selection
Disruptive selection
Sexual selection: caused by competition for access to mates
Name the 2 types of competition:
Inter-sexual (mate competition)
Intra-sexual (competition for dominance hierarchies in one gender)
Which type of selection arises from differences in reproductive success caused by competition for access to mates
Sexual selection
Natural selection
Which type of selection pattern is this?
-selecting traits that are overall positive for adaptation
higher levels of IQ trait expression
Directional
Natural selection
Which type of selection pattern is this?
-balancing selection of traits
birth weight not too heavy or light (median range)
Natural selection
Which type of selection pattern is this?
-extremisms of a trait (both high and low expressions) can be beneficial
Sexual Dimorphism (strong masc fem characteristics)
What is the proportion of total phenotypic variation in the population that is due to genetic variation (h2)?
Heritability
Heritability:
What does this equation stand for?
Not all genetic variance is transmitted from one generation to the next.
Name 1 which is transmitted
Name 2 that are not transmitted
Additive effects
Dominance (interaction of alleles at same locus of chromosome)
and
Epistasis (interaction of alleles at different loci of chromosome) are not
interaction of alleles at different loci of chromosome is known as
Epistasis
interaction of alleles at same locus of chromosome is known as
Dominance
Suggest three possible mechanisms for the evolution of personality:
Selective Neutrality
Mutation-Selection
Balancing-Selection
Are there traits that maybe associated with reproductive success?
measures of FFM
measures of reproductive success:
More children and children who live to 5 year
Ultimate reproductive success = the number of children times the mean survival of children to age 5, given their BMI
Yes, Neuroticism
Greater reproductive success in women is linked to average levels of neuroticism
Very high/low levels of Neuroticism= lower chance of reproductivity
Mutation-Selection:
Assortative mating (people with similar traits should be partnering with one another)
Is there evidence for assortative mating?
Yes: but only for personality traits of Openness and Contentiousness
Husbands who wanted kind-considerate wives got:
one with high Agreeableness and Extroversion
BUT
Wives who wanted kind-considerate husbands got:
ones who were aloof, submissive, unmasculine, unsociable, and unamusing: not universal
Evolution of personality:
Fitness-neutral mutations build up and lead to increased genetic variation in the trait (random variation of trait not necessarily aiding longevity or reproduction)
which type of selection theory is this explaining?
Selective Neutrality
THIS IS NOT CORRECT, theory was proven wrong
Evolution of personality:
Natural Selection (decreasing trait variance) balances the effects of mutation (increasing trait variance)
More susceptible to ‘inbreeding depression’ (siblings mate) and ‘out-breeding elevation’
Not the case for personality
Traits should be sexually attractive and show assortative mating (people with similar traits should be partnering with one another) to an extent but not all
which type of selection theory is this explaining?
Mutation-Selection
THIS IS NOT CORRECT, if everyone paired up with people who were the same level of extroversion, there would be no need for selection
What is Higher extraversion in men linked to?
Greater social status and more children
Evolution of personality:
Extremes of a trait are favoured to the same degree by different environments
Via 2 pathways:
Environmental Heterogeneity
Frequency-Dependent Selection
which type of selection theory is this explaining?
Balancing-Selection
BEST THEORY
Balancing-Selection:
What is the term:
Fitness varies across time and space, and are on average neutral across all spatio-temporal contexts
Environmental Heterogeneity
Balancing-Selection:
What is the term:
Positive = favours traits with high frequency – runaway selection
Negative = favours traits with a low frequency
Frequency-Dependent Selection
Trade-off models: Cost and Benefits
What is the idea that any traits will have an optimum fitness that varies across situations and time
Variable Optima
Name the costs of being OCEAN:
Trade-off models: Cost and Benefits
What is the idea that as the environment changes the associations between trait and behaviour change?
Implication: The adaptability of a trait will therefore depend on context
Environmental heterogeneity
Behavioural Genetics:
All traits are polygenic (affected by multiple mutations at multiple sites) What is the term used to describe this?
quantitative trait loci (QTL)
Which type of study is used to estimate the degree of genetic and environmental influence on a trait
Twin Studies (MZ, DZ)
GWAS studies are expensive. Why is this problematic?
It is more difficult to try and associate specific genes with traits
Higher h2 heritability does not mean that it is easier to find genes associated with the trait
Height has a heritability (h2 ) of .90
GWAS find 54 genes for height, these not the same genes across all studies and account for 5% of the variance
If a personality trait or disorder is very strongly determined by genes (its concordance rate is closer to 0), the expression of a trait eg. SZ would be more prevalent in MD or DZ twins?
MZ twins (Identical)
Genetic effects only emerge with respect to which type of exposure?
environmental exposure
Traits can be inherited across generation but mean levels differ as environments change (Flynn Effect; Twenge Effect)
Genes and environment interact dynamically.
Wrasse fish (females turn into males)
What is the role of environmental or E factor?
Environments can actively control how genes are expressed.
The role of environmental or E factor:
What is associated with
Passive, - random gene depending on the favourability of the environmental conditions it will express
Active, - people gravitate towards specific environments that favour the expression of genetic potential
Evocative - environment interacts and affects your genes vis traits eg. studying in a library will make you more introverted
GE Correlations
The role of environmental or E factor:
What is associated with early exposure to stress hormones during
Uterus
Chorion
c2 – prenatal
The role of environmental or E factor:
What is associated with
Extrafamilial
Age
Sex
Order of siblings in environment
Parent-Child relationship
c2 – postnatal
The role of environmental or E factor:
What is associated with
Postnatal Experience
Chance prenatal events
Temporal Fluctuations
e2
Trait expression:
For traits to be adaptive they need to have some variation
People should have a preferred way to express their trait (their average score on a personality trait) but also be able to express aspects depending on context
Which model describes the expression of certain behaviour varies according to sub change in the environment?
Behavioural Reaction Norms
Eg. A person high in extraversion will be quite in a library, but probably less so than a person who is more of an introvert.
A more introverted person will be more outgoing at a party, than they are on average but probably less so than a more extraverted person.
Behavioural Reaction Norms:
Designed to examine how people change in their expression of behaviour as the environments they are in change.
What are the 2 terms?
Personality
Behavioural plasticity
Findings or Behavioural Plasticity:
Individuals vary as much from moment to moment (with variation) as they do between each other (between variation). True of false?
True
variation within is bigger than between tho
Behavioural Reaction Norms:
Designed to examine how people change in their expression of behaviour as the environments they are in change.
Which term is used to describe the flexible expression of the trait and people have an average response but that they can vary their behaviour depending on context.
Behavioural plasticity
Behavioural Reaction Norms Model
Behavioural Reaction Norms:
Designed to examine how people change in their expression of behaviour as the environments they are in change.
Which term is used to describe the average behavioural response across contexts, how personality is traditionally defined (average response) what traditional personality measures are supposed to tap into.
Personality
Which approach explains that traits reflect ‘accumulation of everyday personality states (Personality) and it also describes the distribution of an individual traits and dynamic interaction with context (contingencies): (Behavioural Plasticity)
Density Distribution Approach
Finding 2 & 3: Personality
Individual have a central tendency (mean) and these are very stable (correlation of .80 and .90)
There is also stability in the amount of variability (.50) – therefor variation is fairly stable and a part of personality to be studied
so basically lots of consistency in the correlation
Which sampling technique looks at the natural history of behaviour.
Assess people at multiple time point (4-8 times a day)
In the last half hour how hardworking have you been…
And looks at the variance
Experience Sampling Methodology (ESM)
Which model is this?
Including bio factors (genes) plus environment which shapes expression of genes, plus traits that allow different ways for personality to be expressed
Socio-Genomic Model
-This implies that both the expression of behaviours associated with trait and the mean level of the trait can vary as a function of (1) the influence of the environment via biological factors (route A) and (2) the dynamic interaction of environment, states (emotions, values, beliefs), biology and the trait. (route B)
When civilian group was paired with Military group, which trait was increased over time?
Agreeableness
What evidence is there that shows that personality may be a neural pathway impacted by drugs?
Extroversion was increased while Neurotism decreases after an 8 week SSRI treatment for patients with depression
Darwinian Mechanisms: Sexual Selection
which term describes
Dominance hierarchies and aggression?
Intra-sexual (competition) selection
Darwinian Mechanisms: Sexual Selection
which term describes
What traits may a life mate desirable?
Inter-sexual (mate selection/choice)
Darwinian Mechanisms: Sexual Selection
What must Sexually selected traits must show?
Variability
-other wise choice and competition are not possible.
if we were all the same (homogeneous) on a trait then who would you choose to be a sexual partner
Miller & Todd’s (1998) Two-Stage Lens Model identifies which 4 cues we may use to identify a good mate?
-Certain traits may survive as they are the basis for selecting a
long term mate
-The preference for the trait and the trait itself are heritable
Participant plays a number of economic games and indicates
how much they would donate to charity.
Play on their own or in dyads watched by someone of the same or
opposite sex.
When Male p were observed by female observer how much did they donate to charity
Men donated much more when observed by a woman
Participant plays a number of economic games and indicates
how much they would donate to charity.
Play on their own or in dyads watched by someone of the same or
opposite sex.
When P were observed by observer regardless the sex (male of female) how much did they donate to charity
around 40%
Which theory describes the fact that it is hard to fake indicators of an animals fitness?
Costly signals offers a solution to the problem of cheating/lying/faking
‘If I can fake a signal of fitness, but don’t have to waste the costs of developing it, then I can get more sexual partners’
The signal has to be high cost, so that only healthy, high status, high condition animals are able to
produce and maintain it. Therefore,
it is a reliable indicator of evolutionary
fitness
Costs can be matter, energy, time, risk,
Peacock’s tail
Costly Signaling Theory
When looking for a partner, what do phenotypes indicate?
Good genes:
Correlate with fitness indicators (fecundity, longevity)
Extraversion and fecundity
Low mutation load
High IQ is linked to lower fluctuating bodily asymmetries (mutation load)
Good Partner:
Show benefits for long term sexual relationships
Loyalty, faithful, generous
Good Parents:
Traits for parental care
Feeding, protection, conflict resolution in siblings, teaching etc..
But these can be faked in humans!
Which 2 components interact with one another to generate personality?
Preference: “I like creative and artistic people”
Trait Expression: Openness to Experience
Preference for a trait (e.g., openness) and the trait itself should not only be correlated in terms of responses but also at a genetic on level.
Both variation in the preference for the trait and the trait itself have to pass onto the next generation
Which theory describes humans signalling our biological potential to be fake?
Costly Signaling Theory
Sexual Selection Hypothesis:
Genetics of Mate Preference and Altruism
