Evolution Flashcards
Adaptations
the working parts - the fundamental systems and subsystems - that animals are made up of.
biological traits that help an animal to survive and reproduce in its habitat. they perform a specific function that make an organism better suited to its environment.
Relevant adaptations
processes that are capable of accomplishing certain tasks that allow us to see, hear and respond to stimuli
Adaptationists
describe how hypotheses about adaptive function guide investigations
Adaptive Functions of Mental Activity
Selective attention
Memory Encoding
Mental Retrieval
Word Recognition
Natural Selection
differential survival and reproduction of organisms as a result of the heritable differences between them - one of the four basic mechanisms of evolution
3 Essential Components of Natural Selection
Individual Differences
Differential Reproduction
Heritable
Individual Differences
within any population, there is variation among individuals for an given characteristic
Differential Reproduction
Caused by individual differences to affect individuals’ chances of surviving and reproducing - some individuals will have more offspring than others
Heritable
traits that five rise to differential reproduction have a genetic basis. The offspring of successful reproducers will resemble their parents with respect to these variable characteristics
Selective Transmission
specific characteristics that are best adapted for survival and reproduction are going to be reproduces at higher rates (as this continues, adaptively undesirable traits are weeded out)
Stabilizing Selection
selection against any sort of departure from the species-typical adaptive design
- keeps traits stable over generations
- selection favours a-typical traits when there has been a significant change in the environment
Darwin’s Finches
drought left only big seeds - large beaks are desirable - they survive to reproduce (small beaks die out)
end of drought led to more small seeds - small beaks are favourable - average beak size returns to normal
Survival of the Fittest
misleading because natural selection doesn’t necessarily favour those who are best at surviving, but also those who are best at reproducing
Darwinian Fitness
average reproductive success of a genotype relative to alternative genotypes (fitness in evolutionary biology does not equal physical fitness)
Evolution
change in genefrequencies over generations - the competition between genotypes to leave copies of themselves
Sexual Selection
the component on natural selection that acts on traits that influence an organism’s ability to obtain a mate. Often no help for survival but contributes to fitness via increased chances of mating
- peacock’s display
- elk courting
Subtypes of Sexual Selection
Female Choice: being chosen by the opposite sex (more attractive)
Success in Combat: defeating same-sex rivals in mating competition
Signs of Sexually Selective Traits
anatomical trait differentiation between sexes
differences existing only during breeding season
Species-Typical Behaviour
physical form
habitat preference
group size
social system
Behaviour Genetics Experiments
keep animals in captivity and selectively breed based on behavioural traits
- can change typical behaviour in a few generations
- animals with short generation times are desired for experiments (usually fruit flies)
Types of Social Behaviour
Cooperation
Altruism
Selfishness
Spite
Cooperation
positive effect on recipient’s well being; positive effect on actor’s well being
Altruism
positive effect on recipient’ well being; negative effect on actor’s well being
behaviour in which the actor incurs a cost to provide a benefit for the recipient
Selfishness
negative effect on recipient’s well being; positive effect on actor’s well being
Spite
negative effect on recipient’s well being; negative effect on actor’s well being
Group Selection
selection favours the good of the group as a side effect of favouring the good of the individual (this does not explain the good of the gene nor does it explain altruism)
Lemings
myth about suicidal population control
one gene for altruistic suicide and one for selfish restraint - the on that leads to altruism will die in the bodies of their suicidal bearers
Eusocial Hymenoptera
includes all ants, some bees and some wasps
most individuals spend their lives serving the colony without reproducing
W.D. Hamilton
troubled by altruism because he believed that standard accounts of natural selection could never code for self sacrifice - realized that genes for altruism could be successful if they left identical copies of themselves
Inclusive Fitness
Direct fitness + indirect fitness
natural selection can favour behaviours that lead to your own reproductive success, but also behaviours that increase the reproductive success of close genetic kin
Direct Fitness
fitness from personal reproduction
Indirect Fitness
fitness from the reproduction of close genetic relatives
Hamilton’s Rule
rB>C
the reproductive benefit to the recipients (B) multiplied by the probability that the recipients actually have identical copies of the same gene, or coefficient of relatedness (r), must be greater than the reproductive cost to the actor (C)
Relatedness
probability that actor and recipient share the gene in question (REVIEW SPECIFICS)
Dr. Daley and Dr. Wilson
found that genetic kin are rarely involved in homicide - child abuse rates are higher amongst step-children than biological children
Mechanisms of Kin Recognition
Neighbours as Likely Kin
Alarm Calls
Cues of Kinship
Neighbours as Likely Kin
in organisms with limited migration, neighbours are more likely to be close kin - be altruistic towards individuals that are spatially close to you
Alarm Calls
altruistic warming of approaching predators
Cues of Kinship
mother’s association, co-residence with other children
Phenotype Matching
an evaluation of relatedness between individuals based on an assessment of phenotypic similarity
De Bruine’s Matching Game - Monetary Gains
player 1 maximizes gains if she trusts player 2; player 2 acts unselfishly
player 2 maximizes gains if player 1 trusts her and then acts sefishly
De Bruine’s Matching Game - Prediction
player 1 will be more trusting of a player 2 who resembles, compared to one who doesn’t (in the experiment, a morphed photo was used)
De Bruine’s Matching Game - Results
subjects were more trusting when face looked like theirs
Direct Reciprocity
individuals help each other and both benefit
Indirect Reciprocity
when individuals help those who ave helped others
