Natural Selection (1) Flashcards
What will we talk about in natural selection
- Evolution 2. Natural Selection 3. Sociobiology 4. Kin selection 5. Reciprocal Altruism 6. Mutualism
What is Adaptation & Evolution
Process of biological change over time
What is evolution (2)
- Change in the FREQUENCY of heritable traits in population from one generation to the next.
- These maybe physical or behavioural
Describe a micro evolution (2)
- Change in the physical or beahvioural traits of a population
- Short time scale & depend on circumstances
Describe a micro evolution - Adaptation (2)
- When the adaptation of a population to local conditions as the result of micro evolution
- Moth changes wing colour
Macro Evolution (2)
1) Long term changes that result in the appearance of a NEW species
What is the difference between Micro and Macro evolution (3)
- They are fundamentally the same,
- The time scale is different
- Extent of change
How do species change over time? (4)
- Mutation
- Geneflow
- Genetic Drift
- Natural Selection
What is the primary driver of species changing out of all 4 components?
Natural selection
Who proposed natural selection
Darwin & Wallace
What 4 fundamental observation facts are key to natural selection (4)
1) Variation
2) Inheritance
4) Overproduction
4) Differential survival and reproduction
What 4 fundamental observation facts are key to natural selection - Variation ?
- Lots of variation for a given trait within a species/ population
ex) Homosapiens: tall and small - black and white - eye colour
What 4 fundamental observation facts are key to natural selection - Inheritance ?
Variations passed from parent to offspring
What 4 fundamental observation facts are key to natural selection - Oveproduction ? (3) & over arching point (1)
1) More born > survive to adulthood
2) Limited resources ( scarcity)
3) Each gen experiences substantial mortality
4) There is competition due to the quantity that survive, to the limited resources, to the experience of death among members. This drives competition to survive
What 4 fundamental observation facts are key to natural selection - Differential survival and reproduction ?
- Only the SURVIVER for resources will survive
2. The ENVIROMENT natural selects some variations from others
Say you survive and your healthy - what is the next important thing to natural selection
Survival and REPRODUCTION is key to understanding adaptation, and evolutionary change over time
What is fitness?
Reproductive success
What is high vs low fitness
lots of kids to no kids
Traits that are well suited to the enviroment give individuals what (2)
1) Advantage in survival and fitness
2) Appear in increased frequency in future generation
Why is the Peppered Moths the perfect examples of natural selection and evolutionary change? 4
1) Evolution change: Operates on the population - no individual moth changed
2) Natural selection: individual survive and reproduce
3) No such things as an absolute best variant - depends on environment
4) Variation HAD to be there in the first place
Do individual evolve
NO progressively a pop changes
The inevitable differential survival and reproductive success in each parental generation AKA natural selection leads to
A change in the FREQUENCY of HERITABLE TRAITS in a POPUlatiON
What is socio biology ?
- Applying evolutionary principles, in particular natural selection to BEHAVIOUR
What do sociobiologist do?
Try to understand how behaviour might be naturally selected / adaptive / evolved
What do sociobiologist ask?
Ask how behviroal variation gives individuals an advantage to survive and reproduce
What are the 3 main ideas of sociobiology (3)
1) Kin selection
2) Reciprocal Altruism
3) Parental investment
What are the 3 main ideas of sociobiology (3) - What is altruism?
Helping / selfless behaviour
What are the 3 main ideas of sociobiology (3) - What is altruism - Biology definition
1) Behaviour that potentially improves the survival & reproductive success of the recipient while potentially endangering the actor
2) Behaviour that helps the recipient and cost the actor
Aultrism examples (2)
1) Predatory call
20 Backing someone up in a fight
How can altruism co exist and be passed on if it may result in behaviour that decreases survival and reproductive success
It may not favour that individual BUT your KIN since it can result in an increase in the contribution to the next generation
It is possible to have some of your traits that can be represeneted in the next generation if they reproduce
How can altruism co exist and be passed on if it may result in behaviour that decreases survival and reproductive success - PREVIOUS theory
Group selection - help out
Kin Selection - Inclusive Fitness (2)
1) Your individual fitness
2) The fitness of your relatives
What does evolutionary theory predict that individuals should do (3) AKA INCLUSIVE FITNESS -1
1) Promote their own survival
2) Promote their own fitness
3) Promote the survival and fitness of their KIN
What is Cooperative Polyandry ? (3)
- In a group of females only one female reproduces and the others help raise offspring.
- Must be related
- Altruistic behaviour
What is Cooperative Polyandry ? Give example
Callitrichidae ( tamarins)
Between who does altruism happen the most in primates
their kin
What is Hamiltons rule? aka selfish benefits
The cost to the donor / aultristic individuals fitness is LESS than the recipient individuals fitness x the degree of relatedness
What is Hamiltons rule - Formula
C < b*r
What is Hamiltons rule - Formula - C, b , r
c = Cost to Aultristic donor b = benefit to donor r = level of relatedness
What is Hamiltons rule - Formula - r
r is from 0-1 where 1 is you and 1
What is nepotism?
Favouritism towards ones kin
What is Female philopatry?
1) a social system in which females remain in the groups or home ranges in which they were born while males leave at sexual maturity
2) this means that a group of females is related it some way - sisters, mothers, aunts, or cousins and these females attract unrelated males.
Who do females affiliate + form alliance with ?
Old world Female kin members with r> .125
The higher the grooming the higher the
relatredness
How does a primate recognize a kin? (3)
1) Odour
2) Facial Recognition
3) Close association between infant and mother results in recognition or familiarity with maternal kin
Why does nepotism drop off? 2
1) Can’t recognize your kind after a certain threshold
2) Reach a level where kin discrimination does not become profitable - r
What are the 3 main ideas of sociobiology (3)
1) Kin selection
2) Reciprocal Altruism
3) Parental investment
What are the 3 main ideas of sociobiology - Reciprocal Altruism- Does altruism happen between non relatives
YES
What are the 3 main ideas of sociobiology - Reciprocal Altruism - Can Altruism between non relativeness be explained by kin selection
Altruism between non relativeness cannot be explained by kin selection rather it is explained by the theory reciprocal altruism
What are the 3 main ideas of sociobiology - Reciprocal Altruism -
Helping behaviour between non-relatives that will be paid back later
What are the 3 main ideas of sociobiology - Reciprocal Altruism - Example
Seyfarth’s grooming for Support Model
What are the 3 main ideas of sociobiology - Reciprocal Altruism - Example - What is the Seyfarth’s grooming for Support Model (2)
1) Grooming between goes up as the hierarchy. Meaning lower ranking members groom more frequently - vice versa
2) support in a conflict goes down the hierarchy. Meaning the higher ranking members provide support at a higher frequency and vice versa
What are the 3 main ideas of sociobiology - Reciprocal Altruism - Example - What is the Seyfarth’s grooming for Support Model - If A is the highest rank and E is the lowest by which member is grooming directed at the most (i), giving the most grooming to the highest member (ii), is getting the most protection (iii)
i) A
ii) B
iii) B
Does “helping” behaviour ever occur between no-kin without evidence of reciprocal altruism?
Yes, this is called mutualism!
Does “helping” behaviour ever occur between no-kin without evidence of reciprocal altruism? - Mutualism
Cooperation between tow or more individuals where each has the potential to gain a direct benefit / shared advantage
Does “helping” behaviour ever occur between no-kin without evidence of reciprocal altruism? - Mutualism - Note because each individuals GAINS it does not fit into our definition of ….
altruism
What does altruism require?
a cost to the actor
Summary: What is altruism
potentially improves survival & fitness while potentially costing the actor
Summary: What is Sociobiology? (3)
1) Used to explain altruistic behaviour
2) Kin selection
3) reciprocal altruism
Summary Behaviours evolved through mutualism may LOOK superficially like altruism, but they aid both participants
IDK MAYBE MUTUALISM? Behaviours evolved through mutualism may LOOK superficially like altruism, but they aid both participants
