What is the Out of Africa Theory?
H.erectus left Africa 1.5mya and H.sapien left Africa 100,000ya. These species replaced all out hominin populations.
What is the Multi-regional theory?
H.erectus left Africa 1.5mya and evolved through gene flow into all other hominin species depending on the area they evolved in.
How many years ago did H.erectus migrate out of Africa?
1.5mya
How many years ago did H.sapien leave Africa according to the OOA theory?
100,000ya
What is Broca’s area concerned with?
Speech- controlling the muscles of jaw, lips, tongue, vocal cords and soft palate that create speech.
What is Wernicke’s area concerned with?
The comprehension of language
What is the cerebellum concerned with?
Hand-eye coordination, balance and fine motor skills.
What behaviours is the cerebellum more developed for?
Bipedal locomotion and tool use
What are the advantages or bipedalism?
- Freeing up hands
- Keeping cool
- Spotting predators
- Energy efficient when walking
- Brandishing tools
What are the disadvantages of bipedalism?
- Lower back problems
- Harder for blood to circulate because of gravity
- Birth more painful
- Human child takes up to year to walk
- Foot arch not properly developed
How did the foramen magnum adapt to bipedalism?
Moved under the skull so that the skull is balanced on top of the spine- requires less muscular energy
How did the spine adapt to bipedalism?
C-curve to S-curve so that weight was kept above the hips
How did the ribs adapt to bipedalism?
Smaller to bring weight closer to spine
How did the pelvis adapt to bipedalism?
Short and wide to reduce stress on upper body and protect internal organs
How did the femur and knee adapt to bipedalism?
Femur became longer and developed valgus angle, allowing leg to swing and remove the lumbering motion of bipedal locomotion
How did the base of the femur adapt to bipedalism?
Became larger to absorb shock
How did the foot adapt to bipedalism?
Arch increased to act as shock absorption
How did hands change from apes to hominins?
- long and curved to short and straight
- thumb got longer and more dexterous
- independent tendons to move last joint of thumb
How did freeing up hand help with brain development?
- allowed for carrying food/ young etc.
- cerebellum became more developed as there was increase in fine motor skills
- hands then became more dexterous which increased food supply and energy for brain
- creation and use of tools became more refined further increasing food supply
= positive feedback loop
What are the possible selection pressures for bipedalism?
- Loss of forests
- Ability to catch food
- Mate selection
- Avoiding predators
- Tool production
- Team work
- Communicating
How does a feature become established in a population?
- Neutral mutation
- Change in selection pressure selects for mutation
-Mutation increases reproductive success - Increased frequency of mutation in next generation
What is biological evolution?
The transmission of genetic information from parents to offspring over time.
What is cultural evolution?
Long-term changes due to ideas and behaviours that were learned and passed onto others. Non-genetic means of adaptation.
What is the NCEA definition of cultural evolution?
Evolution of learned behaviours/ ideas/ beliefs/ abstract thought/ knowledge between generations
