TT2 Flashcards
What is adaptation? What is another name for it?
Short term change in a species (microevolution)
What is evolution? What is another name for it?
Long term change that results in the appearance of a new species (macroevolution)
What is the primary mechanism that fuels change over time?
Natural selection (both adaptation and evolution)
What are the three fundamental facts of natural selection?
- Variation (inter and intraspecific)
- Inheritance
- Overproduction (more offspring produced than # surviving to adulthood)
Survival alone is not the only important thing in understanding evolution. What is the second thing to consider?
Reproduction
What is the ability to live and reproduce?
Fitness
The variance in fitness in each parental generation (________) leads to what?
Natural selection; leads to a change in the frequency of trait appearance. From one generation to the next.
Traits well suited to the environment…? (2)
Given individuals an adaptive advantage (increase fitness)
Increase expression of successful traits in future generations
What are the 4 points about natural selection and evolutionary change?
- Evolution operates on the population
- NS operates on the individual (ind reproduces or doesn’t)
- Variation has to be present
- There is no one better variation
Sociobiology examines _______ and how it affects natural selection.
Behaviour
What are the 3 main ideas behind sociobiology?
Kin selection
Reciprocal altruism
Parental investment
What is the popular definition of altruism? Biological definition?
A nice, selfless act.
An act which increases (benefits the recipient) survival and reproduction at a cost to the actor.
Originally, altruistic behavior was thought to evolve because….
It was for the good of the group
Group selection
What was the problem with group selection?
Altruistic genes reduce in frequency as selfish individuals genes increase in frequency
What is Hamilton’s Law?
Explains the cost of an action must be less than the benefit + degree of relatedness
C<BR
What is inclusive fitness?
The S&R of an individual + weighted S&R of relatives
Why was sexual selection theory developed?
To explain secondary sexual characteristics
Why was a second theory (SS) required to explain secondary sexual characteristics? (3)
Contrary to natural selection:
- SC’s don’t help with survival
- May be detrimental to survival
- Don’t appear until adulthood (although competition to survive occurs before)
According to Darwin, secondary sexual characteristics evolve because of either: (2)
Male-male competition
Female choice
What are the four differences b/w NS and SS?
- NS focuses on surviving to adulthood; SS kicks in at adulthood
- NS focuses on survival; SS focuses on reproduction
- NS selects via physical environment; SS selects via social environment
- SS operates more on males
What is the definition of parental investment?
The investment a parent makes at the cost of investing in other offspring
In parental investment, there is a great potential in conflict between…? (3)
- parent-offspring
- offspring-offspring
- parent-parent
In sociobiology, what are the four factors that differentiate male/female reproductive strategies?
- parental investment
- total reproductive output
- variation in reproductive success
- factors limiting success
What are the 5 main group possibilities?
- Solitary
- Pair living (Monogamous)
- Unimale-Multifemale (Polygynous)
- Multimale-Unifemale (Polyandrous)
- Multimale and female (Polygynandrous)
What is natal/secondary emigration?
First/secondary dispersal away from natal group; not necessarily into a breeding group
What is natal/secondary transfer?
First/secondary dispersal from natal group into a breeding group
Where do dispersing primates go? (3)
- stay solitary
- disperse into same sex groups
- disperse into bisexual groups (breeding groups)
When do dispersing primates go? (2) Primary/secondary + mvf
Primary - at maturity
Secondary
m - 5 years, perhaps due to mating choice and success
f - typically stay in group after reproducing (exception: gorilla and maybe howlers)
What is the difference between proximate and ultimate explanations?
P - immediate causes (trigger)
U - evolutionary reasoning
What are the two variants of group cohesion?
Cohesive and fission-fusion
What are the differences b/w cohesive and f-f primates? (5)
Group size, coordination, home ranges, sub-group formation, spatial proximity
What are the new terms of f-f dynamics?
High f-f (low cohesion)
Low f-f (high cohesion)
What 5 things do we examine to quantify f-f dynamics?
- size
- composition
- spread
- stability
- segregation by age/sex
Why do primates live in groups at all? (and 3 d’s)
Predation protection
detection
dilution
defense
What are five possible reasons of variation in kinds of groups?
Phylogeny - taxonomic differences (similarities - ie: cercopithecines and male dispersal)
Population density
Predation - red colobus monkeys in Tai and Gombe forests
Infanticide - parallel w/ predation
Feeding competition
What are the two types of feeding competition (2) and how do they effect within group social response? (4)
Contest and scramble
- Female residency/dispersal
- Differentiated/Undifferentiated relationships
- Dominance hierarchies/egalitarian
- Social bonds/no social bonds
What is the Human Obstetrical Dilemma and what are four adaptations females possess in light of this?
aka human infant challenge. Human big head + bipedalism (narrower birth canal).
- unfused skull plates
- hormones loosen pelvis
- very early birth
- obligatory midwife
What are two potential reasons primates might want to take care of someone else’s children?
- juvenile females learning to mother
2. mother relief hypothesis (kin selection + inclusive fitness)
What are the four socializing agents in infant care?
- mothers
- alloparents (aunting/infant care)
- adult males
- peers
What is the range of interactions b/w males and infants? (5)
- intensive caregiving (monogamous nwm)
- affiliation (some baboons)
- tolerance (some macaques)
- use and misuse (gelada)
- infanticide (gorillas, langurs, colobus, cebus, many others)
Why would males interact with infants? (2)
- kin selection
2. sexual selection
Why do males commit infanticide? (5)
- nutrition (cannibalism)
- reduce competition
- sexual selection (lactational amhorrenea)
- byproduct of aggression
- abnormal nonadaptive pathology
Explain three characteristics of the transition to adulthood (puberty)
- higher mortality
- natal dispersal
- more gradual for males than females
What are the three types of mother parity (experience)?
- nulliparous
- primiparous
- multiparous
