L3 - Evolution of the Cognitive Brain Flashcards
What is evolution
- Descent with modification
- Species changing over time
Step by Step of natural selection
1) Env change
2) Stress = adaptation
3) Survival = reproduction
4) Gene pool decreases, new population all has same gene
5) ONLY happens when genetic variability is present to begin with
Give two examples of natural selection?
- Darwin’s finch beak lengths e.g dry env = bigger beak = more seeds
- Black death survivors had a gene preventing them from dying easily from it, but are more vulnerable now for autoimmune diseases
What key things do you need for natural selection to take place?
- variation
- competition
What factors are key for having successful offspring?
- Survival: ensuring you and kid survive
- Sex: ensuring there is a way to have them & competitive advantage being given through genetics
What was the old kind of cortex?
Allocortex, replaced by neocortex
What is the neocortex?
- Folded thing on brain
- For sensory stuff
- More neocortex = more likely to live in groups with complex societies
- Evolved from allocortex
What is the advantage of the neocortex
- Better sensory and motor coordination
- Bigger visual, parietal and frontal lobes
- More flexible and good at adapting
Example of colourvision
- Primates have 3 cones as mammals lost rods through being nocturnal
- Others have more
- Mammals are not visually driven, we are driven by other things too
How did they test the colour theory for primates?
- seeing the fruit
- If the reg/green fruit is better and is different through eyesight sensitivity for different animals.
- Go to places where animals get food, measure all light, work out signal/noise ratio
- The colour is very optimal for finding fruit in foliage.
How did humans emerge?
1) Diff skeletons
2) Trading, hunting, rituals, stood upright, use of fire and tools
3) Second wave of humans travelled the world from africa, caused interbreeding, survived ice ages etc. (Neanderthals)
4) Third wave - Homosapiens left africa
5) Homosapiens outcompeted other species probably due to group size and diseases
How did cortical areas change?
- Expansion in frontal areas, parietal and temporal lobes, as well as sensory and motor cortexes
Evidence that we use our brains
- Very expensive: uses a lot of calories
- Deaths in childbirth
- Childhood mortality: more vulnerable than other animals
How have brain functions changed from an evolutionary perspective?
- Parietal lobe: relationships of space/numbers, quantity relationships become deeper e.g math
- Temporal lobe: recognition of objects ], grows into generalisation of concepts
