Anatomical Adaptations Flashcards
Advantages of bipedalism are:
- Enables the animal to look over tall vegetation to spot predators, sources of food
- Can fight more effectively (wing their arms)
- Arms can be used to communicate and make signals
- Arms can be used to throw things
- Arms can carry things (tools, make containers so can carry more)
- Develop fine manipulative skills (tool use/writing)
4 adaptations are:
Bipedalism
Opposable thumbs
Skin colour
Surface area to volume ratio
Opposable thumbs are advantage because:
Thumb can be lined against the fingers
•allows manipulation of tools (helping them hunt and build shelters - increased chances of finding food and protected them from predators and harsh weather)
•develop grip (power - grasping large objects, precision - holding small objects)
Main pigment in human skin is …
Melanin
Melanin absorbs…
UV radiation stopping it from damaging the tissues underneath (darker skin, more melanin, better UV protection)
Melanin also interferes with the process of synthesising…
Vitamin D
Dark skin in sunny places is an advantages because more melanin protests you from UV radiation, but the intensity and length of daylight still allows the production of enough…
Vitamin D
In less sunny places, dark skin affected their ability to synthesise vitamin D - sun was less intense and daylight hours lower - so skin colour of these humans gradually became…
Paler due to a reduction in melanin
Less melanin in less sunny parts = advantage because it allowed the production of…
Enough vitamin D but was still enough to protect the skin from the less intense UV radiation in these areas
To synthesise enough vitamin D means reduces the chance of developing…
Rickets
Some Homo erectus people would have had alleles that have them slightly less pigmentation in their skin. These individuals would have absorbed more UV radiation and would have had a better supply of vitamin D. Less likely to develop rickets so would have survived and passed on their…
Alleles to their children
Mutations causing less melanin in the skin would have been a…
Selective advantage - live in more temperate regions (Europe) would have evolved paler skins
Surface area to volume ratio varies due to different ethnic groups being adapted to…
Different climates
Hot climate, a long-limbed body shape gives a larger surface area to volume ratio so it is easier to…
Lose body heat (increasing survival)
Cold climate, a more compact (shorter, broader) body shape decreases the surface area to volume ratio and helps to…
Conserve heat (increasing survival)
