Evolution I Flashcards
What is an adaptation?
Biological traits that help an individual survive and reproduce in its habitat
Perform specific functions that make an organism better suited for its environment
What adaptations have helped racoons see in the dark?
Front paws became so sensitive that they often don’t require vision to discriminate food items from non-food items in total darkness
Are human eyes an adaptation?
Yes
What classifies as a “higher” mental process?
Selective Attention
Memory Encoding
Memory Retrieval
In what way are cognitive psychologists also adaptationists?
They break down large-scale cognitive processes into adaptive problems or tasks, and then look for adaptations to solve those problems
What are the four basic mechanisms of evolution?
Natural selection
Mutation
Genetic drift
Migration
What is natural selection?
Differential survival and reproduction of organisms as a result of the heritable differences between them
What are the three essential components of natural selection?
1) Variation amongst individuals
2) Differential reproduction success
3) Heritability
What is stabilizing selection?
Selection against any sort of departure from the species-typical adaptive design
Describe the situation with Darwin’s Finches and how it shows natural selection
There was a drought
Only food left were large, hard, tough seeds
Large beak Finches survived whereas small beak Finches died
(When the drought ended, average sized beaks became more frequent again)
What is Darwinian fitness?
Avg reproductive success of a genotype relative to other genotypes
Is natural selection the “survival of the fittest”?
No, natural selection maximizes fitness, which is more about reproductive success than survival
What is evolution?
Change in gene frequencies over generations
What is sexual selection?
The component of natural selection that acts on traits that influence an organism’s ability to obtain a mate
What are the two subtypes of sexual selection? Give examples of each
1) Female choice
2) Success in combat
What are the mate choice preferences of peahens (female peacocks)?
1) Number of eyespots
2) Left-right symmetry of eyespots
What traits do females tend to look out for when choosing a mate?
- Best resistance to disease
- Best genes for being healthy
How are Sanderling sandpipers different from semipalmated or Dunlin sandpipers?
Foraging behaviour
- race out after receding waves
- furiously peck at tiny insects on sand
- race back to shore in front of next wave
What classifies as species-typical behaviour?
- Physical form (topography) of the way an animal moves
(ex. do they hop?) - Habitat preference (where they go, what they eat, how they pursue and capture it)
- Group size (do they travel in flocks, etc.)
- Social system (do they mate monogamously, etc.)
What are selection experiments/behavioural genetics studies used for?
A way to confirm that behaviour evolves
What are selection experiments/behavioural genetics studies?
Selectively breeding those with extreme traits (i.e. most or least aggressive) and change the animal’s typical behaviour
How were selection experiments/behavioural genetics studies used for dogs?
People had created dog breeds for selective purposes (i.e. dogs that would kill badgers, etc)
Why is the fruit fly a popular candidate in genetics studies?
It has a short generation time (possible to see multiple generations in a short amount of time)
True or false: adaptations happen for the good of the species
False
They’re for the good of the gene, not the entire group
Why is foraging in groups advantageous?
a) Increases personal success of obtaining food
b) Increases group success of obtaining food
c) both a) and b)
C
Why is foraging in groups advantageous in terms of fitness trade-offs?
One member cannot forage and look out for predators at the same time. When in a group, few individuals can look up while others forage.
How does the rate of head-jerks amongst individual Golfinches correlate with the total number of head-jerks for the whole flock?
As group size increases, individual head jerks decrease while total number of head jerks increase
What is altruism?
Behaviour in which the actor incurs a cost to provide a benefit for the recipient
Is foraging in groups considered altruism? Why or why not?
No
The actor benefits
What is an important component of altruism?
It has to be passed down genetically, otherwise it can’t thrive
What is direct fitness?
Fitness from personal reproduction
What is indirect fitness?
Fitness from the reproduction of close genetic relatives
What is inclusive fitness?
Direct fitness + indirect fitness
What is Hamilton’s rule? (the expression)
Br > C
B = reproductive benefit to the recipient r = coefficient of relatedness C = cost to actor
What is relatedness?
The probability that the actor and recipient share the same gene in question; depends on how genes were inherited (i.e. from mother/father, uncle/aunt, etc.)
What is the r value for mom/dad?
0.5
What is the r value for first cousin?
0.125
What is the r value for aunt/uncle?
0.25
What is the r value for full siblings?
0.5
What is the r value for half siblings?
0.25
What is the r value for grandparents?
0.25
When talking about eusocial Hymenoptera, why do many individuals help the colony but do not reproduce themselves?
Colonies are founded of a small number of individuals, therefore they are very closely related
What is the relationship between aggression and relatedness?
As relatedness increases, aggression decreases
*Explains aggression between colonies
What did Dr. Daly and Dr. Wilson find about homicide?
25% of homocides are by ‘relatives’
6% are by actual genetic-relatives
Before sexual maturity, we recognize “kin” as people who are….
Living close to us
How do children recognize their mothers as ‘kin’?
She reared them from infancy
She breastfed them
She smells different
How do children recognize their siblings?
They watch them perform the same acts (as above) with their mother
They live together for a number of years
Describe the pattern of alarm calls in ground squirrels
Females give calls more often when they live near kin
Males leave kin early on and almost never give alarm calls
What is phenotype matching?
Mechanism of kin recognition
Evaluation of relatedness between individuals based on an assessment of phenotypic similarity
What is self-referential phenotype matching?
Phenotype matching by comparing yourself with another individual (as opposed to comparing a known family member with another individual)
Why do we help people who don’t look like us?
Reciprocity
What is direct reciprocity?
Situations where individuals help each other and both benefit
What is indirect reciprocity?
Individuals who help others who have helped others
Earn a better reputation, etc.
What was Dr. Debruin’s study on altruism?
Player 1 could not trust the other player and keep their money; or trust the other player and have a chance at getting more money
Player 2 could betray the other player and get more money or Player 2 could behave unselfishly and reward Player 1 but get less money themselves
Player 1 was more likely to trust Player 2 if Player 2 resembled Player 1
