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